Well done, however there is one more issue that could be mentioned as I have experienced which is the fuel pump pressure. I believe the Q-jet carb is supposed to operate at a fuel pressure range between 4.5 - 7 depending on the vehicle it’s on. Mine happens to be on a Chevy 5.7 V8 and the fuel pump is putting out 11.5psi without a regulator which is over powering the needle and seat and was causing fuel to dump directly into the manifold and sometimes onto the manifold. I have since placed a Holley regulator set to 5.5psi and the thing runs great. Just an FYI...
That's exactly what's happening.... today I got home reached under the carburetor and got a handful of gas I'm going to check for intake leaks also. thank you so much for your video! I am going to pull the carburetor apart and I'll be watching your video and studying it very closely... I am subscribed very educational
Thanks for spending time to explain the workings of the carb, I have 2 on Crusader V8's and 1 is running rich, now I know the engineering behind how they work I can look at investigating the problem with a good idea of what to look for. Thank you for spending the time to explain and show its internals.
I'm so glad I found your video. I had the quadrajet on my 79 gmc rebuilt last June and have under 1000 miles. My truck just died on me last week. I had it towed home last week. I took the plugs off and found all the plugs with heavy carbon. I would not start and thought it was my distributor. . I changed that out cause it was under warranty and got it started but found the gas was coming out from the pump plunger and around the top gasket. The truck starts after its cold big starts to die out as it warms up. I'm guessing it's the float or seat like you say. I wax getting ready to order a new Edelbrock but I'm going to check the seats and floats first. I hope that's it. Thanks again
thank you so much you have literally kept me from presently living in this Texas Rv park forever, lol. I'm from Boston. don't get me wrong Texas is Great but its too damn HOT and HUMID. I'm gonna start taking apart the carb tomorrow and checking everything float wise. I can't thank you enough.
Hi, I've been tinkering with Rochester Quadrajet for 40-years years I guess, I'm old lol. I just bought a 1984 K5 Blazer in San Francisco, 350 crate engine, it's got California emissions which means it has a pulsating valve on the passenger front side of the carburetor. Anyways I drove it from California 4300 miles to New York, and the last stretch of the trip it started running rich at idle and the fuel mileage dropped. So my first thought was those well plugs, but I talked to a couple of rebuilders and they said they seldom cause a problem. So I'm going to open the carburetor up as soon as the rain stops, and I did put a new fuel filter in before I left California, but that was 4300 miles and many many Phillips, so maybe some dirt got past the filter, maybe the needle is slightly worn or not seating properly. It was a rebuild carburetor, but who knows how long ago since this is a 35 year old truck. I've opened up many Quadrajets over the years, and I always have trouble with that power valve plastic ring snapping back into place and getting the gasket and all the tubes perfectly aligned. But I do have several parts carburetors that I've collected over the years, along with so many other Chevy parts. I'll make a video of my results, and I post videos of all kinds of stuff regularly, maybe you'll enjoy watching mine the way I enjoyed watching yours. Oh yeah, last thing, what's that pulsating valve on the front pass side of the carburetor called? I've also seen it on 1981 Oldsmobile 307. Cadillac with an Olds or Chevy engine etc. Could that be something that affects the accelerator pump action like one fella mentioned to me the car show last weekend?
Thx. for the video's... So, I have a Quadrajet (factory) on my '71 Ford 429 cj Mustang. It has not run right since I bought the car already rebuilt by somebody. It spews black smoke and actual wet fuel droplets at idle and is marginally better once the choke is fully open. Basically the car runs rich at all times... I had a guy look at the carb, both on and off the car. He seemed pretty knowledgeable. We checked everything, trying to get this engine to run proper; timing, fuel pressure, choke operation, changed plugs, checked the well plugs, you name it. He even tested the CO output and actually in the end tried to set the carb solely on the amount of CO being produced by the engine. The factory calls for something like 4-5 ppm, off the top of my head. He set the idle speed just where it would not go off the idle circuit causing more gas to enter the engine. However, the engine still run's rich, real rich... I have not been able to drive the car on a regular basis in four year's since completing the rotisserie restoration - truth... The engine was rebuilt and I spent a lot of $$$ bringing the entire car back to factory specs, including buying this date matching rare Ford Q-jet at a cost of $1400.00 - yep that much! Your video does not offer me anything new that I can check, maybe more of something that I can recheck once again... A question I have for you is the term, "factory idle circuit setiings". Apparently as per my guy these are preset and non adjustable somewhere in the carb. He felt that the factory setting had become altered due to the fact that the thickness of the rebuild gasket used by the shop between the base and upper body of the carb was too thick??? He indicated that he opened the sealed factory setting up and made an adjustment to allow for the new thickness of this aftermarket gasket so as to bring the idle circuit back in line to factory settings. I am confused about this... Anyway, if you have any expertise you care to share on my plight with my very expensive show quality rebuilt Ford used Q-jet, I would like to hear back from you. Cheers.
Hey bud: That's a rare, rare carb. However, no real differences from one used on a GM big-block, like a Buick or Pontiac other than linkage and external variations. I realize you don't have a familiarization with carbs, but I would encourage you to learn all you can about it. Regarding the idle circuit: The "circuits" in the carb are factory-drilled passages that transfer fuel from the float bowl down to the area in the baseplate where the idle mixture screws are. Along that route, there are a pair(one each side) of additional vertical passages that draw in air to mix with the fuel. Those are called air bleeds. All of those tiny passages are impossible to modify. So, there are NO adjustments to be made to the idle mixture or idle speed other than external adjustments to fine-tune them. That stuff about the gasket thickness I think is someone trying to pass you off with an excuse because it doesn't affect anything other than the adjustment of the rods that run up to the accelerator pump and choke, and that's only imperceptibly. The very first thing i suggest you do is try to borrow a good running Quadrajet from someone to see whether your engine is capable of running right. Many people have chased carb problems that turned out to be distributor issues, cam issues, valvetrain issues, etc. In other words don't blame the carb until that's all there is left to blame. If the engine runs good, then you know you have a poorly rebuilt carb. If it has the same issues with the borrowed carb, then you know there is some other issue with the engine itself. To "me", it sounds like a simple issue of a sticking float or dirty inlet needle. Remember, carb float works just like a toilet float. If it sticks, the liquid keeps on running until it overflows. Be sure you change that gas-thinned oil ASAP. Good luck!
Just barely made it home from a long day at work. it was night time when I left work. this Carter is flooding real bad I can't figure it out I check the choke plates sprayed a whole bunch of carburetor cleaner. but now that I've watched your video I know the pin must have some sort of dirt in it cuz I'm getting fuel everywhere it's coming out of the carburetor through the sides thank you for your video Tyler I sure do appreciate it
You're welcome. Just remember that carb floats work just like toilet floats. When the fuel needs to shut off when the bowl is full, it has to shut OFF, otherwise you get fuel everywhere.
8:35 -the press-fit plugs in the bottom! Nobody EVER mentions this,and I know that more than one person has had problems with them leaking. I might pull the carb off the Chevelle,and make a video about it myself.
I am suspecting this on my bus. I rebuilt the carb about a year ago and noticed that they had previously been covered with JB weld. It looked solid so I just left it alone. It's been starting to run richer over the last few months, and after a couple hard backfires now it's running so rich it's barely driveable. Figured I'd do some quick internet research before tearing it apart, but this is going to be the first thing I'll check. It's had a hard life and I wouldn't be surprised if the JB weld cracked or broke off. At any rate I know someone else has had this problem before on mine.
My 327 1968 corvettes quadrojet is flooding right now. It’s brand new and clean but I know nothing about them nor did my “mechanic” that was “hooking me up”…. I’ve just gotten her back after a nightmare year and 7 months waiting for this guy thinking he was trying to steal my car by making it unaffordable. I literally went picked it up and drove it home while he was still turning screws. It was close to 8 grand in repairs for what was supposed to be a $4000 tune up and “refresh” originally… and then a new carburetor (couldn’t figure out the original Holley he stole off of it) and then a gas tank kit and then brakes and then 10 other things I could have done myself or didn’t even need to be done. Most of it was unwarranted. I’m sick of waiting, excuses and getting robbed. I’m sure after watching a few of these videos I’m going to be able to work on my own, and actually get it right without nickel and diming myself to death with lightbulbs and gauges when I want the car running. I came across the car at a deal by helping a friend yadda yadda and it’s not going to turn into a money pit just to be able to drive. I work as a machinist and my hobby is firearms and gunsmithing so I am surely capable.Time to learn something new so I just subscribed my friend, with a brand new sense of confidence. Thanks.
We had two 1968 Vettes. One was black, nearly new, and the second was a red, originally green convertible that came much later. The red convertible is still floating around out there. You can fix yours. A quadrajet is intimidating only the first time you work on it. Remember that EVERY problem has a cause and even a novice mechanic's job is to learn what that problem is. Work like a doctor...treat the cause, not the symptom. I would use my videos as reference and also grab the How to rebuild your Quadrajet book that is still out there and take your carb off and go through it yourself. Keep in mind that a carb won't work right on an out of tune engine.
I had rebuild my quadrajet carburetor twice now and I m tired spending $250 per,, tired of getting crap from the cheap gas there making and all the soot in the bottom of the tank, so I decide to cut off one inch of the pickup line and see if that will solve the problem of flooding.
Mine Quadra jet brand you ordered it out for Internet. I received it. about three days ago. My car has a fuel pump electric I have tried fuel pressure regulator, but it still running rich to where is smoking a little bit of black smoke. I watched your video and thank you for the video, want to ask you What pressure Do I need on the Quadra jet or do you might have any ideas what would be causing it to run rich to burn your eyes it don’t do it when it first starts running. It’s after it runs a little while then it starts smoking a little bit black and then starts burning your eyes.
Hi great video! I just rebuilt my dual jet because of flooding but it still floods,If I look down the barrels I can see it dripping out when motor is running straight down into the engine. My needle and seat is new and installed correctly Any Advice ??
Thanks for the video. The Q jet you are working on has a dome with an adjustment on top on the left front of the bowl. Do you know what circuit this adjust? I can't find any info on this, not even a part number. Please help if you can. Thanks
I have a E4ME carburetor that is running rich no matter what I do. Rebuilt it twice, new float second time, set everything factory, never touched the air bleed valve still plugged, never touched the rich mixture stop screw still capped. The m/c solenoid works from what I can tell while running also... new tps, all vacuum lines hooked up correctly, fuel gets into the vaccum canister (not the charcoal can) from the float bowl vent. I'm at a loss of wft it could be... float level? I set it to spec... 🤦♂️🤦♂️🤦♂️
Great videos very informative . After watching a lot of them I got inspired to put a new Quadra jet on my 1985 k10 Was in the process of fine-tuning it and getting the choke to function correctly but when I shut it off after about 30 seconds my muffler exploded what in the world would cause that to happen? Any advice on how to proceed would be greatly appreciated Thanks
I think you answered my question about gas on top of the carb at the accelerator pump. It looks like the carb is due a rebuild. Mine is running rich bad.
When I see videos on carburetor adjustments I see everyone talk about the Jets I see everyone talk about the floats and I see everyone talked about the choke but no one ever talks about that pain in the middle of the float that is adjustable what is that and how does it work
Ok so I'm not flooding externally, but idle mixing screw don't change,timing is right. My question is if at idle is there suppose to be fuel coming out of those center ring jets or just the bottom mixing screws. I look down the choke plate and there is noticeable fuel coming out in those middle rings. The motor is running ok but has a lope. Ok it's a Rochester two barrel on an s10 2.8l seems nobody has any information on these on utube can u please help me out thanks, Tim
My quadrajet on my 85 seems like it's dumping a ton of gas into the engine. Not over flowing but I can see/smell fuel on the spark plugs. Before giving it a few taps u could see fuel coming out of the exhaust manifold. Ran good before I replaced all the freeze plugs.
Just put rebuilt carb on poured up gas everywhere. Rebuilt mine fid the same thing. Watched your vid and redid float still doing the same thing. Its on a 455 olds in a gmc motor home.
Thanks tyler, great video. I have one flowing fuel out the slot between the primary and secondaries so I'm assuming stuck float or debris in the needle seat so I'll be checking that. I know that these carburetors are tough to adjust. Can I take it apart to this point without messing up major adjustments? Thanks again for the great information.
I have a quadrajet with a manual choke and often times at a low rpm it will sputter one time and make a spitting noise when it does the sputter then close the choke on its own. What could this be?
Flooding also occurs when the primary power valve seal fails. Quadrajet.com sells this seal as a split seal, cut the old seal off of the power valve and replace with new split seal. the power valve works off vaccine on the power valve piston.
Great tutorial. I have a question regarding what would cause dieseling upon showdown of a motor. I have a 85 Blazer K5 with a 305 , all stock, all original, the quad jet has never been touched since it rolled out of the assembly plant. The truck has ordinal 92k miles, was bought new . A few years ago it started idling high , 1500-1700 rpm and wouldn’t kick down for nothing, i managed to lower the idle but it doesn’t do anything for the dieseling which is severe upon shut down. To prevent the dieseling I’m forced to shut down the truck while in drive gear, what do you recommend that I should look at first? Thank you
I have a 1988 Olds Cutlass Supreme with a 5.0 liter engine and the 4 barrel electronic quadrjet carb on it. I had some electrical issues with the car and didn't know it and replaced the distributor, carb, spark plugs and wires, and fuel filter trying to fix the car from dying on me. Found out the wires on the alternator were burned and frayed and causing a short. So I then replaced the alternator and battery and the wiring that goes to the alternator. I had gone through 3 rebuilt carbs and figured the car would run fine now. Well, the check engine light wasn't coming on anymore and it wasn't dying on me but the idle was so low the car wouldn't idle sitting still. For a temporary fix, I moved the cruise control rod to one position up and that worked to keep it running at a stop. It had no power much still but wasn't choking out when I accelerated like before. I felt like the car's timing wasn't set right and that the new carb needed adjustment. I just took it to the shop this week and they set the timing, which was out, and adjusted the carb. I went to pick it up and it started great. Then when I went to pull out of the repair shop's lot, it started bucking and spitting when I tried to give it gas. I turned around and took it right back to them. The guy who had fixed it had gone to lunch and told me to bring it back next day. I was afraid I wouldn't make it home, but as long as my foot was on the gas, it would stay running. Now the idle is real rough, but it has power and takes the gas. I talked to the repair man today and he just shook his head and said it could be the carb. I told him it was brand new rebuilt and he said it could still be bad. So I told him I still had the other "new" rebuilt carb I had taken off and replaced with this one and maybe it would work? He said it might....but who knows. I have had this car for 29 years and taken good care of it but it seems unfixable for the past 5 years. ANY SUGGESTIONS????
The first suggestion is to change shops and get one that is reputable. These cars are not hard to repair but they require someone who has intuitive diagnostic ability rather than just read a scanner. There have been a lot of parts "thrown" at your car to get it to run right and obviously none did any good. The very first thing is check and adjust the base timing per the sticker on the fan shroud. The computer controls the spark advance so there are no adjustments other than base timing. There are miles of vacuum lines on that engine that need to be checked for breaks and routed to the proper device. The EGR valve needs to be checked that it isn't stuck open...it will barely idle if it is. The carburetor is also computer controlled and there ARE no adjustments on it. The only thing to check is that the choke is opening all the way when the engine is warm. You didn't mention whether this is a US or Canadian car. Canadian cars do not have the same engine and the computer controls as the US versions. You might call your local Chevrolet/Buick dealer and ask them if they still have a mechanic old enough to have worked on those cars when they were fairly new. If so, you might inquire discreetly whether he would be interested in fixing your car on his own time, or you can go through the dealer as long as they are fair about it. Good luck!
@@TylersNeighborhoodGarage Thanks for your advice. I agree with getting someone who knows what they are doing but that is getting harder and harder around here. The EGR valve was replaced, the vacuum lines all replaced and made sure they were in the proper places. I did find one that was off the front of the carb after this garage had worked on it and I put it back on. Still runs rough on idle. He said he set the timing to 0 but the sticker on the fan shroud says it is supposed to be set to 20. He said you have to run the vin# to get the timing setting. Looks like that was wrong too. Our local GM dealers suck at fixing anything so I don't trust them with this. I called the garage back and told him about the vacuum line and he is going to check it again tomorrow. I am going to say something to him about the timing too. Thanks again.
Hi Tyler! Great video series on these. Quick question though..... have you ever come across the early 65' and 66' QJets? They're quite different than the ones they made in 67' and onwards as they had a weird diaphragm inlet needle and a fuel damped secondary rather than the vacuum break style. I have one..... have not come across a single clip on CZcams that shows them and their troublesome features.
my quad randomly floods. either after a few full throttle runs or anytime when its cold. gas comes out the top and I take it off and the airhorn off. the gas level is normal along with float. needle isn't stuck. and the primary rods aren't stuck. it runs great and idles good when warm and not acting up. could clogged air bleeds cause this$
From trial and error I found out from dealing with thermoquad's and quadrajets don't use any epoxy except for : marine-tex white epoxy ! This the only thing that will seal up the fuel bowel metal plugs/plastic caps ! You just have to make sure the area is sanded ruff or sand blasted on and around the plugs and then properly cleaned. And apply marine-tex takes 48 hours to make it's fully cured! It's the only epoxy that stood the test of being submerged in gasoline for 48 hours with no leaks and no deterioration .
My needle valve was just sitting in the seat. No little wire to dangle from the float. I do have an older carb from a 1972 cutlass but I'm guessing that it's still suppose to dangle? Correct? Awsome vid though very informative!
a Tyler u helping me I got a 350 quadrajet u teaching me and I'm drinking u a good dam teacher a u need make a book on dis and a full DVD ima watch all videos u got thank up for u being able too show me
I’m trying to solve a fuel mileage issue with mine. I used to average 17mpg hiway and lately I’m getting 13. Spark plugs have tan deposits. No black. Oil doesn’t smell like gas. No idea why my mileage fell off the face of the earth.
Hey, I Rebuilt my quadrajet because it was leaking gas from around the accelerator pump. After rebuilding I have the same problem. Checked float level 3-4 times. Will I faulty fuel pump cause THIS? I haven't checked fuel pressure yet but I should only have 3-5 psi right. Any ideas about this?
Gerald Crutchfield double check your float level . Make sure your needle is on the float in the right position . wher it hangs on the float . Take any fillters out of fuel inlet ! Run a good in line gas filter ! The glass tube kind . Little pieces of rust will tear through the paper filter resulting in flooding ! Go to my youtube channel The Weldor . Thers good tips in ther . I also show how to properly fix well plugs so they dont leak . Dont band aid with epoxy . waste a time !
Once you go past half throttle the secondary throttle plate will start to open. However, the upper portion of the throttle plates don’t open until the air demand reaches a certain point.
Hey Tyler. Im doing my first Q-Jet rebuild ever and your videos are just what I was looking for to talk me through it. I have a couple questions if you have time. My carb is off an 84 chevy pickup. Carb number is 17084226. Mine does not have a needle and seat. It has a piece that screws into the body where the needle and seat would go, and has a little rubber washer or diaphragm. The kit I was given for this build HAS an needle and seat. Does it replace the "Diaphragm" type one that I have. Also In this particular video you see the dome shaped area with a screw in the top on the passanger side of the carb. My carb just has a big empty hole where that is, although the air horn has a relief built into it to house the dome shaped area. Is something missing from my carb or did some not have the internals in that area?
I have never heard of something like that originally installed in a Quadrajet. It's possible that it's a repair assembly designed to work around stripped or damaged inlet seat threads. Does it have a small plunger that looks like the end of the float would act upon it? Are there o-rings on it? Even the early Q-jets that had a bolt-on seat used a needle valve. As long as the replacement, original-style seat will screw in and tighten then it's perfectly fine to use it. Remember there is a small metal washer that goes under the seat, supplied in the kit.
www.tocmp.com/manuals/Carbs/Rochester/QJet/HTML/MCarbRoch1973_4M_0003.htm Here is something I found that talks about it.I dont think its very common My Brother has built a bunch of Q-Jets over the years and he says hes never seen it either Il send you a link to a video if you would like to see what it looks like. It is pretty much like you described Im going to put the video up on youtube anyway but will take me a bit so check in with my page later if you want . Thanks.
I overhauled my quadrajet a few years ago and the chock never worked the same after that. Any suggestions why it would stop working? The chock worked just fine before hand. The strange thing that i couldn't figure out is when you overhaul the carb you don't even touch the choke. I overhauled it because it was leaking gas through the gaskets. I've watched most or all of your vids. (thanks for sharing them) Any idea's on why it would stop working? Another issue i'm having is my car (78 olds delta 88) is running SUPER rich. I'm gonna mess with the air mixture screws in the morning and hopefully i can lean her up a bit. Thanks again!
Use a vacuum gauge on your biggest vacuum port on bottom of carb when adjusting air/fuel mixture. Set them both to the highest point of vacuum. Starting with the fuel mixture.
Great video... I have a question on an issue i'm having with a rochester 4jet. I'm not sure if this is normal or not, but when its idling ....i can see fuel dripping down the secondaries onto the plate.
Thanks, you're probably right...i've dialed down the pressure from 8.5lbs to 4. I'll take a look and see if the dripping has stopped. It does seem to run better. I'm trying to avoid taking it apart to adjust the floats again. I measured them last time and were spot-on according to the sheet that came with the kit.
I have a new rebuilt quadrajet from a reputable company. When I had it off, I was working on the intake and I accidently placed it on its side... Not realizing what I did. I found it running Rich and preventing my start on three 77 Corvette. Would my new carb have this issue?
Very unlikely. Check that the choke is working correctly first. Is it dumping gas out anywhere? Check all your bases first as far as your engine before blaming the carb. If you feel the carb is the culprit, then do NOT tinker with it. Just send it back for a replacement.
Rebuilt mine but can't get it to idle down?? Disconnected choke and backed out both idle screws (not air mixture screw) still won't come down below 1200 rpm ??
I've got a '69 Buick Electra 225/430cu.in that's hard starting when sitting too long. Have too pump the pedal multiple times to get the fuel to flow. I've heard that the new higher ethanol fuels have a different specific gravity that requires older carbs to need different calibration or different floats. Do you have any ideas about that?
B. E. Atles if you have to pump it a lot . That more than likely means your secondary metering well plugs are leaking . Thats wher the gas sits till you start it again . Well plugs leak the fuel out . So your starting it dry . Ya pump it till the fuel bowl is filling up again and then it lights off . I show how to properly fix well plugs on my youtube channel The Weldor ! Dont waste time slobberin epoxy on them ! Common problem on q jets !
B. E. Atles not sure how to copy a link but youtube channel The Weldor . Youll see D dog with some saftey glasses on ! One shows how to properly install secondary metering well plugs . Ive ran premium 91 octane my whole life ! 40 years now ? You definetly get a cpl more miles to the gallon with it over 85 octane . You can run more timing with it . Timing builds horsepower . My crowd plugs the vacum advance on the distributer . That way you can run more intial timing ! Makes the bottom end a little stronger and snappier . I run my sbc stuff at around 16 degrees with the vaccum advance always plugged . My last trip ta phenoix my stock 400 averaged 16.6 miles ta the gallon ! Once i got down ther i had ta take about 6 , 8 degrees out of it cause she was knockin . Another guy that went down with his 5.9 cummins in his dodge we raced around with . My 400 sbc ate that 5.9s lunch for the 2 weeks we were down ther ! If we did a rolling like 20 mph race . Hed be about a truck length back . From a dead start . Id get him by about 4 truck lengths ! Spreadbores pull like a train when ther set up right ! If i can help in anyway just hollar brother ! Be safe !
After I run the car for a while and turn off the engine, it will chug a few times like it is still trying to run before it quits. Then, unless I wait a while, I have a hard time getting it started again. Could this be because the carb is running too rich / flooding?
A good way to check is use a bright flashlight to peer down in the carb throat after a shutdown(with the engine off) and see whether you observe gas dripping out into the throat of the carb, which would indicate a problem. Also check whether the choke is open ALL the way when the engine is warmed up. The ethanol gas we have now tends to boil easily, so besides the couple checks I recommended, you should make sure the base timing is spot-on, no vacuum leaks, and ensuring the engine isn't running too hot.
good video, I have a question I have a 1988 Monte Carlo SS that shows code 21 which is the tps sensor I changed the tps sensor and I'm still getting the the check engine light with the same code, do you think I should rebuild the carburetor?
Did you clear the code from the ECM first? Disconnect the battery, leave disconnected for a few minutes then reconnect. That should reset the ECM. Then start and run the car and see if the fault codes reappears.
my quad runs good at idle right after starting as long as you let it idle. Once i get the boat up on plane and run for a bit, slow it back to idle, it floods the engine off. what would i look at
Float level first of all. It sounds like it needs a general overhaul anyway, and setting float height is part of that. I'd replace the float as well. You may want to run it with the cover and air cleaner off temporarily and watch whether the vent tube on the carb is discharging fuel when it does this flooding bit. That will confirm a float issue.
@@GJJC13 should be able ta get a reasonable priced gauge . Rule of thumb back in the day was manually check it . Get a clean cas can or jug . Should be a no less than a pint of gas every 15 seconds !
@@GJJC13 the factory filters will also restrict flow if your secondaries open all the way . If you shut it off and 15 mins later its floodin . 90 percent a the time its the secondary metering well plugs . I did a vid on my channel on how to replace them !
I just purchased a 1969 Chevy C-20. I got it from a lady who's Father purchased it new. Most of it is still original! I took off the air cleaner to spray carb cleaner on carburetor and found a small ball bearing, like a steel bb, right next to the exellerator pump. What the could that be?
They are NOT steel well plugs ! Do NOT slobber epoxy on them . The gas will desolve the epoxy and yr carb will be flooding in 30 days again ! Go to my youtube channel The Weldor . I show how to properly fix your well plugs from leaking ! Ther aluminum plugs with aluminum solder . The solder cracks and starts dripping fuel out the secondary metering well . They make a well plug kit ! Takes 10 mins ta properly fix well plugs ! Ive rebuilt 70, 80 a these ? ben running them for almost 40 years now ! Ill take a Q-jet over any other carb every time ! Gotta know how ta set em up though !
u goning to make DVDs I will buy your first 1 I got my car in shop they said they set my timing on my Delta but I don't see how when Carb flooding out but if u make dvdv I want 1st copy and ima build my Carb up and put video saying how u help me make a monster out my Carb plus people going to hate cause you showed me sum a 22 experience machnic. can't do
Well done, however there is one more issue that could be mentioned as I have experienced which is the fuel pump pressure. I believe the Q-jet carb is supposed to operate at a fuel pressure range between 4.5 - 7 depending on the vehicle it’s on. Mine happens to be on a Chevy 5.7 V8 and the fuel pump is putting out 11.5psi without a regulator which is over powering the needle and seat and was causing fuel to dump directly into the manifold and sometimes onto the manifold. I have since placed a Holley regulator set to 5.5psi and the thing runs great. Just an FYI...
awesome, thank you
That's exactly what's happening.... today I got home reached under the carburetor and got a handful of gas I'm going to check for intake leaks also. thank you so much for your video! I am going to pull the carburetor apart and I'll be watching your video and studying it very closely... I am subscribed very educational
Thanks for spending time to explain the workings of the carb, I have 2 on Crusader V8's and 1 is running rich, now I know the engineering behind how they work I can look at investigating the problem with a good idea of what to look for. Thank you for spending the time to explain and show its internals.
I'm so glad I found your video. I had the quadrajet on my 79 gmc rebuilt last June and have under 1000 miles. My truck just died on me last week. I had it towed home last week. I took the plugs off and found all the plugs with heavy carbon. I would not start and thought it was my distributor. . I changed that out cause it was under warranty and got it started but found the gas was coming out from the pump plunger and around the top gasket. The truck starts after its cold big starts to die out as it warms up. I'm guessing it's the float or seat like you say. I wax getting ready to order a new Edelbrock but I'm going to check the seats and floats first. I hope that's it. Thanks again
Wow thanks you for this, I think my 82 Cadillac eldorado needs carburetor rebuild and you sir just educated me very nicely, God bless.
Glad to help.
thank you so much you have literally kept me from presently living in this Texas Rv park forever, lol. I'm from Boston. don't get me wrong Texas is Great but its too damn HOT and HUMID. I'm gonna start taking apart the carb tomorrow and checking everything float wise. I can't thank you enough.
Hi, I've been tinkering with Rochester Quadrajet for 40-years years I guess, I'm old lol. I just bought a 1984 K5 Blazer in San Francisco, 350 crate engine, it's got California emissions which means it has a pulsating valve on the passenger front side of the carburetor. Anyways I drove it from California 4300 miles to New York, and the last stretch of the trip it started running rich at idle and the fuel mileage dropped. So my first thought was those well plugs, but I talked to a couple of rebuilders and they said they seldom cause a problem. So I'm going to open the carburetor up as soon as the rain stops, and I did put a new fuel filter in before I left California, but that was 4300 miles and many many Phillips, so maybe some dirt got past the filter, maybe the needle is slightly worn or not seating properly. It was a rebuild carburetor, but who knows how long ago since this is a 35 year old truck. I've opened up many Quadrajets over the years, and I always have trouble with that power valve plastic ring snapping back into place and getting the gasket and all the tubes perfectly aligned. But I do have several parts carburetors that I've collected over the years, along with so many other Chevy parts. I'll make a video of my results, and I post videos of all kinds of stuff regularly, maybe you'll enjoy watching mine the way I enjoyed watching yours. Oh yeah, last thing, what's that pulsating valve on the front pass side of the carburetor called? I've also seen it on 1981 Oldsmobile 307. Cadillac with an Olds or Chevy engine etc. Could that be something that affects the accelerator pump action like one fella mentioned to me the car show last weekend?
Thx. for the video's... So, I have a Quadrajet (factory) on my '71 Ford 429 cj Mustang. It has not run right since I bought the car already rebuilt by somebody. It spews black smoke and actual wet fuel droplets at idle and is marginally better once the choke is fully open. Basically the car runs rich at all times... I had a guy look at the carb, both on and off the car. He seemed pretty knowledgeable. We checked everything, trying to get this engine to run proper; timing, fuel pressure, choke operation, changed plugs, checked the well plugs, you name it. He even tested the CO output and actually in the end tried to set the carb solely on the amount of CO being produced by the engine. The factory calls for something like 4-5 ppm, off the top of my head. He set the idle speed just where it would not go off the idle circuit causing more gas to enter the engine. However, the engine still run's rich, real rich... I have not been able to drive the car on a regular basis in four year's since completing the rotisserie restoration - truth... The engine was rebuilt and I spent a lot of $$$ bringing the entire car back to factory specs, including buying this date matching rare Ford Q-jet at a cost of $1400.00 - yep that much! Your video does not offer me anything new that I can check, maybe more of something that I can recheck once again... A question I have for you is the term, "factory idle circuit setiings". Apparently as per my guy these are preset and non adjustable somewhere in the carb. He felt that the factory setting had become altered due to the fact that the thickness of the rebuild gasket used by the shop between the base and upper body of the carb was too thick??? He indicated that he opened the sealed factory setting up and made an adjustment to allow for the new thickness of this aftermarket gasket so as to bring the idle circuit back in line to factory settings. I am confused about this... Anyway, if you have any expertise you care to share on my plight with my very expensive show quality rebuilt Ford used Q-jet, I would like to hear back from you. Cheers.
Hey bud: That's a rare, rare carb. However, no real differences from one used on a GM big-block, like a Buick or Pontiac other than linkage and external variations. I realize you don't have a familiarization with carbs, but I would encourage you to learn all you can about it.
Regarding the idle circuit: The "circuits" in the carb are factory-drilled passages that transfer fuel from the float bowl down to the area in the baseplate where the idle mixture screws are. Along that route, there are a pair(one each side) of additional vertical passages that draw in air to mix with the fuel. Those are called air bleeds.
All of those tiny passages are impossible to modify. So, there are NO adjustments to be made to the idle mixture or idle speed other than external adjustments to fine-tune them. That stuff about the gasket thickness I think is someone trying to pass you off with an excuse because it doesn't affect anything other than the adjustment of the rods that run up to the accelerator pump and choke, and that's only imperceptibly.
The very first thing i suggest you do is try to borrow a good running Quadrajet from someone to see whether your engine is capable of running right. Many people have chased carb problems that turned out to be distributor issues, cam issues, valvetrain issues, etc. In other words don't blame the carb until that's all there is left to blame. If the engine runs good, then you know you have a poorly rebuilt carb. If it has the same issues with the borrowed carb, then you know there is some other issue with the engine itself.
To "me", it sounds like a simple issue of a sticking float or dirty inlet needle. Remember, carb float works just like a toilet float. If it sticks, the liquid keeps on running until it overflows. Be sure you change that gas-thinned oil ASAP. Good luck!
Your teaching pretty well people gotta pay attention thanks for the video
Dear.. you are real capable teaching
Such experience baised on knowledge
Real exlent demonstration , hope UTUBE consider how it was useful teaching
Hey Tyler, thanks so much for this video. Great job and a lot of help for a novice like me.
Just barely made it home from a long day at work. it was night time when I left work. this Carter is flooding real bad I can't figure it out I check the choke plates sprayed a whole bunch of carburetor cleaner. but now that I've watched your video I know the pin must have some sort of dirt in it cuz I'm getting fuel everywhere it's coming out of the carburetor through the sides thank you for your video Tyler I sure do appreciate it
You're welcome. Just remember that carb floats work just like toilet floats. When the fuel needs to shut off when the bowl is full, it has to shut OFF, otherwise you get fuel everywhere.
You answered my problems. When you touch base on the float and needle having trash around the rubber tip
Thank u 4 such a great and detailed video. Very helpful!
Yes def watch the whole video. Thank you sir. Will watch some more. Great video
The secondary air valve can cause where are you located?
Great set of videos!
Great video. Extremely informative.
Thank you for doing these videos.
8:35 -the press-fit plugs in the bottom! Nobody EVER mentions this,and I know that more than one person has had problems with them leaking.
I might pull the carb off the Chevelle,and make a video about it myself.
I am suspecting this on my bus. I rebuilt the carb about a year ago and noticed that they had previously been covered with JB weld. It looked solid so I just left it alone. It's been starting to run richer over the last few months, and after a couple hard backfires now it's running so rich it's barely driveable. Figured I'd do some quick internet research before tearing it apart, but this is going to be the first thing I'll check. It's had a hard life and I wouldn't be surprised if the JB weld cracked or broke off. At any rate I know someone else has had this problem before on mine.
go for it
PhattyMo go to my youtube channel The Weldor . I show how to install well plugs properly and other tips
Can you do a video about the altitude compensating side of quadrajet
This video really helped me. Thank you man!
I rebuilt the carburetor with a kit that has the new version of the needle valve and seat. Do you have any suggestions why fuel leaks thru the ex
My 327 1968 corvettes quadrojet is flooding right now. It’s brand new and clean but I know nothing about them nor did my “mechanic” that was “hooking me up”…. I’ve just gotten her back after a nightmare year and 7 months waiting for this guy thinking he was trying to steal my car by making it unaffordable. I literally went picked it up and drove it home while he was still turning screws. It was close to 8 grand in repairs for what was supposed to be a $4000 tune up and “refresh” originally… and then a new carburetor (couldn’t figure out the original Holley he stole off of it) and then a gas tank kit and then brakes and then 10 other things I could have done myself or didn’t even need to be done. Most of it was unwarranted. I’m sick of waiting, excuses and getting robbed. I’m sure after watching a few of these videos I’m going to be able to work on my own, and actually get it right without nickel and diming myself to death with lightbulbs and gauges when I want the car running. I came across the car at a deal by helping a friend yadda yadda and it’s not going to turn into a money pit just to be able to drive. I work as a machinist and my hobby is firearms and gunsmithing so I am surely capable.Time to learn something new so I just subscribed my friend, with a brand new sense of confidence. Thanks.
We had two 1968 Vettes. One was black, nearly new, and the second was a red, originally green convertible that came much later. The red convertible is still floating around out there. You can fix yours. A quadrajet is intimidating only the first time you work on it. Remember that EVERY problem has a cause and even a novice mechanic's job is to learn what that problem is. Work like a doctor...treat the cause, not the symptom. I would use my videos as reference and also grab the How to rebuild your Quadrajet book that is still out there and take your carb off and go through it yourself. Keep in mind that a carb won't work right on an out of tune engine.
Thanks for the video, my quadrajet was flooding even so much as to getting fuel into one of the vacuum lines, turns out my float was set too high.
I had rebuild my quadrajet carburetor twice now and I m tired spending $250 per,, tired of getting crap from the cheap gas there making and all the soot in the bottom of the tank, so I decide to cut off one inch of the pickup line and see if that will solve the problem of flooding.
My carb choke is stuck wide open cold. How do I fix stuck choke?
Please advise
Mine Quadra jet brand you ordered it out for Internet. I received it. about three days ago. My car has a fuel pump electric I have tried fuel pressure regulator, but it still running rich to where is smoking a little bit of black smoke. I watched your video and thank you for the video, want to ask you What pressure Do I need on the Quadra jet or do you might have any ideas what would be causing it to run rich to burn your eyes it don’t do it when it first starts running. It’s after it runs a little while then it starts smoking a little bit black and then starts burning your eyes.
Hi great video!
I just rebuilt my dual jet because of flooding but it still floods,If I look down the barrels I can see it dripping out when motor is running straight down into the engine.
My needle and seat is new and installed correctly
Any Advice ??
hey i have question for you the screw on the top of the choke linkage it has spring on it does it mater how it's ajusted ??
I have a cam. Not stock 350. Had to back idel screws out 6 turns to get it to ideal right rockchester carb.
Good Video!
Thanks for the video. The Q jet you are working on has a dome with an adjustment on top on the left front of the bowl. Do you know what circuit this adjust? I can't find any info on this, not even a part number. Please help if you can. Thanks
Can the fuel pump pressure too high cause flooding. I put on an electric in line pump. 1.5 - 5 psi
I have a E4ME carburetor that is running rich no matter what I do. Rebuilt it twice, new float second time, set everything factory, never touched the air bleed valve still plugged, never touched the rich mixture stop screw still capped. The m/c solenoid works from what I can tell while running also... new tps, all vacuum lines hooked up correctly, fuel gets into the vaccum canister (not the charcoal can) from the float bowl vent. I'm at a loss of wft it could be... float level? I set it to spec... 🤦♂️🤦♂️🤦♂️
Great videos very informative . After watching a lot of them I got inspired to put a new Quadra jet on my 1985 k10 Was in the process of fine-tuning it and getting the choke to function correctly but when I shut it off after about 30 seconds my muffler exploded what in the world would cause that to happen? Any advice on how to proceed would be greatly appreciated Thanks
What about gas not getting sprayed into venturi? Gas being pumped to carb ?
Thanks for the Video! It really helped me. It's not proffessional, but that's what i like ;-) Car guys helping car guys!.
Thanks man.
What could be wrong when only one side of the primary. Flood. On a quadrajet. Cab.
I think you answered my question about gas on top of the carb at the accelerator pump. It looks like the carb is due a rebuild. Mine is running rich bad.
Good video bro 👌 👍
Holly smoke....I've never seen so many weeds on a lawn....lol
When I see videos on carburetor adjustments I see everyone talk about the Jets I see everyone talk about the floats and I see everyone talked about the choke but no one ever talks about that pain in the middle of the float that is adjustable what is that and how does it work
Ok so I'm not flooding externally, but idle mixing screw don't change,timing is right. My question is if at idle is there suppose to be fuel coming out of those center ring jets or just the bottom mixing screws. I look down the choke plate and there is noticeable fuel coming out in those middle rings. The motor is running ok but has a lope. Ok it's a Rochester two barrel on an s10 2.8l seems nobody has any information on these on utube can u please help me out thanks, Tim
Great video thanks for the help
My quadrajet on my 85 seems like it's dumping a ton of gas into the engine. Not over flowing but I can see/smell fuel on the spark plugs. Before giving it a few taps u could see fuel coming out of the exhaust manifold. Ran good before I replaced all the freeze plugs.
Just put rebuilt carb on poured up gas everywhere. Rebuilt mine fid the same thing. Watched your vid and redid float still doing the same thing. Its on a 455 olds in a gmc motor home.
I like this video and the comments, Quadrajets are super-carbs
Great video thank u for your time doing it
At 0:07 where you have two springs for the metering rods, mine has one spring and an adjustment screw. I don't see it in my carb sheet. What is it?
What happens if your carburetor has no choke like they took it off??
Very informative, I appreciate you brother!
Thanks tyler, great video. I have one flowing fuel out the slot between the primary and secondaries so I'm assuming stuck float or debris in the needle seat so I'll be checking that. I know that these carburetors are tough to adjust. Can I take it apart to this point without messing up major adjustments? Thanks again for the great information.
Definitely could
I have a quadrajet with a manual choke and often times at a low rpm it will sputter one time and make a spitting noise when it does the sputter then close the choke on its own. What could this be?
Flooding also occurs when the primary power valve seal fails. Quadrajet.com sells this seal as a split seal, cut the old seal off of the power valve and replace with new split seal. the power valve works off vaccine on the power valve piston.
+Bernie Smith Yes. Thank you for noting that.
If the float is set to high will that cause flooding as well?
yes!
Great tutorial. I have a question regarding what would cause dieseling upon showdown of a motor. I have a 85 Blazer K5 with a 305 , all stock, all original, the quad jet has never been touched since it rolled out of the assembly plant. The truck has ordinal 92k miles, was bought new . A few years ago it started idling high , 1500-1700 rpm and wouldn’t kick down for nothing, i managed to lower the idle but it doesn’t do anything for the dieseling which is severe upon shut down. To prevent the dieseling I’m forced to shut down the truck while in drive gear, what do you recommend that I should look at first? Thank you
Had a vacuum leak on a 79 corvette that caused exactly that.
I have a 1988 Olds Cutlass Supreme with a 5.0 liter engine and the 4 barrel electronic quadrjet carb on it. I had some electrical issues with the car and didn't know it and replaced the distributor, carb, spark plugs and wires, and fuel filter trying to fix the car from dying on me. Found out the wires on the alternator were burned and frayed and causing a short. So I then replaced the alternator and battery and the wiring that goes to the alternator. I had gone through 3 rebuilt carbs and figured the car would run fine now. Well, the check engine light wasn't coming on anymore and it wasn't dying on me but the idle was so low the car wouldn't idle sitting still. For a temporary fix, I moved the cruise control rod to one position up and that worked to keep it running at a stop. It had no power much still but wasn't choking out when I accelerated like before. I felt like the car's timing wasn't set right and that the new carb needed adjustment. I just took it to the shop this week and they set the timing, which was out, and adjusted the carb. I went to pick it up and it started great. Then when I went to pull out of the repair shop's lot, it started bucking and spitting when I tried to give it gas. I turned around and took it right back to them. The guy who had fixed it had gone to lunch and told me to bring it back next day. I was afraid I wouldn't make it home, but as long as my foot was on the gas, it would stay running. Now the idle is real rough, but it has power and takes the gas. I talked to the repair man today and he just shook his head and said it could be the carb. I told him it was brand new rebuilt and he said it could still be bad. So I told him I still had the other "new" rebuilt carb I had taken off and replaced with this one and maybe it would work? He said it might....but who knows. I have had this car for 29 years and taken good care of it but it seems unfixable for the past 5 years. ANY SUGGESTIONS????
The first suggestion is to change shops and get one that is reputable. These cars are not hard to repair but they require someone who has intuitive diagnostic ability rather than just read a scanner. There have been a lot of parts "thrown" at your car to get it to run right and obviously none did any good. The very first thing is check and adjust the base timing per the sticker on the fan shroud. The computer controls the spark advance so there are no adjustments other than base timing. There are miles of vacuum lines on that engine that need to be checked for breaks and routed to the proper device. The EGR valve needs to be checked that it isn't stuck open...it will barely idle if it is. The carburetor is also computer controlled and there ARE no adjustments on it. The only thing to check is that the choke is opening all the way when the engine is warm. You didn't mention whether this is a US or Canadian car. Canadian cars do not have the same engine and the computer controls as the US versions. You might call your local Chevrolet/Buick dealer and ask them if they still have a mechanic old enough to have worked on those cars when they were fairly new. If so, you might inquire discreetly whether he would be interested in fixing your car on his own time, or you can go through the dealer as long as they are fair about it. Good luck!
@@TylersNeighborhoodGarage Thanks for your advice. I agree with getting someone who knows what they are doing but that is getting harder and harder around here. The EGR valve was replaced, the vacuum lines all replaced and made sure they were in the proper places. I did find one that was off the front of the carb after this garage had worked on it and I put it back on. Still runs rough on idle. He said he set the timing to 0 but the sticker on the fan shroud says it is supposed to be set to 20. He said you have to run the vin# to get the timing setting. Looks like that was wrong too. Our local GM dealers suck at fixing anything so I don't trust them with this. I called the garage back and told him about the vacuum line and he is going to check it again tomorrow. I am going to say something to him about the timing too. Thanks again.
Hi Tyler! Great video series on these. Quick question though..... have you ever come across the early 65' and 66' QJets? They're quite different than the ones they made in 67' and onwards as they had a weird diaphragm inlet needle and a fuel damped secondary rather than the vacuum break style. I have one..... have not come across a single clip on CZcams that shows them and their troublesome features.
put the quote mark before the number. like this : '65 or '67. it is taking the place of the number 19 .
Good job
my quad randomly floods. either after a few full throttle runs or anytime when its cold. gas comes out the top and I take it off and the airhorn off. the gas level is normal along with float. needle isn't stuck. and the primary rods aren't stuck. it runs great and idles good when warm and not acting up. could clogged air bleeds cause this$
only with the chok closed does Rochester 4G keep running
you have a clogged fuel passage somewhere. Dissasemble and let sit in a solvent bath for several days, then blow out every passage with air.
My quadrajet is spitting at full throttle, could it be the float or the seat sticking ?
From trial and error I found out from dealing with thermoquad's and quadrajets don't use any epoxy except for :
marine-tex white epoxy ! This the only thing that will seal up the fuel bowel metal plugs/plastic caps ! You just have to make sure the area is sanded ruff or sand blasted on and around the plugs and then properly cleaned. And apply marine-tex takes 48 hours to make it's fully cured! It's the only epoxy that stood the test of being submerged in gasoline for 48 hours with no leaks and no deterioration .
marine tex is the best
john barrett they make a secondary well plug kit . Go to my channel The Weldor . I show how to properly fix well plugs !
My needle valve was just sitting in the seat. No little wire to dangle from the float. I do have an older carb from a 1972 cutlass but I'm guessing that it's still suppose to dangle? Correct? Awsome vid though very informative!
Correct. A kit will have all of that. Glad you enjoyed.
a Tyler u helping me I got a 350 quadrajet u teaching me and I'm drinking u a good dam teacher a u need make a book on dis and a full DVD ima watch all videos u got thank up for u being able too show me
+Guy St Louis You are very welcome.
I’m trying to solve a fuel mileage issue with mine. I used to average 17mpg hiway and lately I’m getting 13. Spark plugs have tan deposits. No black. Oil doesn’t smell like gas. No idea why my mileage fell off the face of the earth.
Hey, I Rebuilt my quadrajet because it was leaking gas from around the accelerator pump. After rebuilding I have the same problem. Checked float level 3-4 times. Will I faulty fuel pump cause THIS? I haven't checked fuel pressure yet but I should only have 3-5 psi right. Any ideas about this?
Gerald Crutchfield double check your float level . Make sure your needle is on the float in the right position . wher it hangs on the float . Take any fillters out of fuel inlet ! Run a good in line gas filter ! The glass tube kind . Little pieces of rust will tear through the paper filter resulting in flooding ! Go to my youtube channel The Weldor . Thers good tips in ther . I also show how to properly fix well plugs so they dont leak . Dont band aid with epoxy . waste a time !
Thanks for the information brother, question when do the 4 barrels open? I'm new to the Quadrajet. I have mine on a 455 olds, I believe.60 over.
Once you go past half throttle the secondary throttle plate will start to open. However, the upper portion of the throttle plates don’t open until the air demand reaches a certain point.
Hey Tyler. Im doing my first Q-Jet rebuild ever and your videos are just what I was looking for to talk me through it. I have a couple questions if you have time. My carb is off an 84 chevy pickup. Carb number is 17084226. Mine does not have a needle and seat. It has a piece that screws into the body where the needle and seat would go, and has a little rubber washer or diaphragm. The kit I was given for this build HAS an needle and seat. Does it replace the "Diaphragm" type one that I have. Also In this particular video you see the dome shaped area with a screw in the top on the passanger side of the carb. My carb just has a big empty hole where that is, although the air horn has a relief built into it to house the dome shaped area. Is something missing from my carb or did some not have the internals in that area?
I have never heard of something like that originally installed in a Quadrajet. It's possible that it's a repair assembly designed to work around stripped or damaged inlet seat threads. Does it have a small plunger that looks like the end of the float would act upon it? Are there o-rings on it? Even the early Q-jets that had a bolt-on seat used a needle valve.
As long as the replacement, original-style seat will screw in and tighten then it's perfectly fine to use it. Remember there is a small metal washer that goes under the seat, supplied in the kit.
www.tocmp.com/manuals/Carbs/Rochester/QJet/HTML/MCarbRoch1973_4M_0003.htm Here is something I found that talks about it.I dont think its very common My Brother has built a bunch of Q-Jets over the years and he says hes never seen it either Il send you a link to a video if you would like to see what it looks like. It is pretty much like you described Im going to put the video up on youtube anyway but will take me a bit so check in with my page later if you want . Thanks.
I overhauled my quadrajet a few years ago and the chock never worked the same after that. Any suggestions why it would stop working? The chock worked just fine before hand. The strange thing that i couldn't figure out is when you overhaul the carb you don't even touch the choke. I overhauled it because it was leaking gas through the gaskets. I've watched most or all of your vids. (thanks for sharing them) Any idea's on why it would stop working? Another issue i'm having is my car (78 olds delta 88) is running SUPER rich. I'm gonna mess with the air mixture screws in the morning and hopefully i can lean her up a bit. Thanks again!
Use a vacuum gauge on your biggest vacuum port on bottom of carb when adjusting air/fuel mixture. Set them both to the highest point of vacuum. Starting with the fuel mixture.
Great video... I have a question on an issue i'm having with a rochester 4jet. I'm not sure if this is normal or not, but when its idling ....i can see fuel dripping down the secondaries onto the plate.
+Travis Madison that's not normal. Sounds very much like fuel level is too high
Thanks, you're probably right...i've dialed down the pressure from 8.5lbs to 4. I'll take a look and see if the dripping has stopped. It does seem to run better. I'm trying to avoid taking it apart to adjust the floats again. I measured them last time and were spot-on according to the sheet that came with the kit.
@@TravCanFixit 8.5lbs of fuel pressure is way to high. Mine run good at around 5-6lbs usually with Q-jets.
I have a new rebuilt quadrajet from a reputable company. When I had it off, I was working on the intake and I accidently placed it on its side... Not realizing what I did. I found it running Rich and preventing my start on three 77 Corvette. Would my new carb have this issue?
Very unlikely. Check that the choke is working correctly first. Is it dumping gas out anywhere? Check all your bases first as far as your engine before blaming the carb. If you feel the carb is the culprit, then do NOT tinker with it. Just send it back for a replacement.
Rebuilt mine but can't get it to idle down?? Disconnected choke and backed out both idle screws (not air mixture screw) still won't come down below 1200 rpm ??
Check the timing. If it's too far advanced at idle it will override the idle screw.
It's in the same place as it was with the Holley and it idled fine with it.
I've got a '69 Buick Electra 225/430cu.in that's hard starting when sitting too long. Have too pump the pedal multiple times to get the fuel to flow. I've heard that the new higher ethanol fuels have a different specific gravity that requires older carbs to need different calibration or different floats. Do you have any ideas about that?
B. E. Atles if you have to pump it a lot . That more than likely means your secondary metering well plugs are leaking . Thats wher the gas sits till you start it again . Well plugs leak the fuel out . So your starting it dry . Ya pump it till the fuel bowl is filling up again and then it lights off . I show how to properly fix well plugs on my youtube channel The Weldor ! Dont waste time slobberin epoxy on them ! Common problem on q jets !
@@theweldor757 Thanks. I'll look at your site. Which one is it? I kinda figured that, but was trying to wish it away. lol
B. E. Atles not sure how to copy a link but youtube channel The Weldor . Youll see D dog with some saftey glasses on ! One shows how to properly install secondary metering well plugs . Ive ran premium 91 octane my whole life ! 40 years now ? You definetly get a cpl more miles to the gallon with it over 85 octane . You can run more timing with it . Timing builds horsepower . My crowd plugs the vacum advance on the distributer . That way you can run more intial timing ! Makes the bottom end a little stronger and snappier . I run my sbc stuff at around 16 degrees with the vaccum advance always plugged . My last trip ta phenoix my stock 400 averaged 16.6 miles ta the gallon ! Once i got down ther i had ta take about 6 , 8 degrees out of it cause she was knockin . Another guy that went down with his 5.9 cummins in his dodge we raced around with . My 400 sbc ate that 5.9s lunch for the 2 weeks we were down ther ! If we did a rolling like 20 mph race . Hed be about a truck length back . From a dead start . Id get him by about 4 truck lengths ! Spreadbores pull like a train when ther set up right ! If i can help in anyway just hollar brother ! Be safe !
After I run the car for a while and turn off the engine, it will chug a few times like it is still trying to run before it quits. Then, unless I wait a while, I have a hard time getting it started again. Could this be because the carb is running too rich / flooding?
A good way to check is use a bright flashlight to peer down in the carb throat after a shutdown(with the engine off) and see whether you observe gas dripping out into the throat of the carb, which would indicate a problem.
Also check whether the choke is open ALL the way when the engine is warmed up. The ethanol gas we have now tends to boil easily, so besides the couple checks I recommended, you should make sure the base timing is spot-on, no vacuum leaks, and ensuring the engine isn't running too hot.
good video, I have a question I have a 1988 Monte Carlo SS that shows code 21 which is the tps sensor I changed the tps sensor and I'm still getting the the check engine light with the same code, do you think I should rebuild the carburetor?
Jose Boyzo qw
Pp
Did you clear the code from the ECM first? Disconnect the battery, leave disconnected for a few minutes then reconnect. That should reset the ECM. Then start and run the car and see if the fault codes reappears.
Could be wiring
Thanks !!!
my quad runs good at idle right after starting as long as you let it idle. Once i get the boat up on plane and run for a bit, slow it back to idle, it floods the engine off. what would i look at
Float level first of all. It sounds like it needs a general overhaul anyway, and setting float height is part of that. I'd replace the float as well. You may want to run it with the cover and air cleaner off temporarily and watch whether the vent tube on the carb is discharging fuel when it does this flooding bit. That will confirm a float issue.
Tyler's Neighborhood Garage make sure your fuel pump isnt over pressuring . should be about 5 ta 7 psi
@@theweldor757 How can I measure the psi of my fuel pump?
@@GJJC13 should be able ta get a reasonable priced gauge . Rule of thumb back in the day was manually check it . Get a clean cas can or jug . Should be a no less than a pint of gas every 15 seconds !
@@GJJC13 the factory filters will also restrict flow if your secondaries open all the way . If you shut it off and 15 mins later its floodin . 90 percent a the time its the secondary metering well plugs . I did a vid on my channel on how to replace them !
I just purchased a 1969 Chevy C-20. I got it from a lady who's Father purchased it new. Most of it is still original!
I took off the air cleaner to spray carb cleaner on carburetor and found a small ball bearing, like a steel bb, right next to the exellerator pump.
What the could that be?
Is it possible that it can run fine and occasionally flood then clear up
+Mario Braga Sure. That tends to happen more often when you are passing rust and debris through the fuel system.
They are NOT steel well plugs ! Do NOT slobber epoxy on them . The gas will desolve the epoxy and yr carb will be flooding in 30 days again ! Go to my youtube channel The Weldor . I show how to properly fix your well plugs from leaking ! Ther aluminum plugs with aluminum solder . The solder cracks and starts dripping fuel out the secondary metering well . They make a well plug kit ! Takes 10 mins ta properly fix well plugs ! Ive rebuilt 70, 80 a these ? ben running them for almost 40 years now ! Ill take a Q-jet over any other carb every time ! Gotta know how ta set em up though !
Nice Lawn Boy...lol !!
i just rebuilt my quad. it was missing the cap/ lid to left of needle seat. but vehicle ran prior
I misread that needle hanger part I guess. Back apart
JB Weld, (Just Barely Weld).
I Subscribed!
Accelerator pump
u goning to make DVDs I will buy your first 1 I got my car in shop they said they set my timing on my Delta but I don't see how when Carb flooding out but if u make dvdv I want 1st copy and ima build my Carb up and put video saying how u help me make a monster out my Carb plus people going to hate cause you showed me sum a 22 experience machnic. can't do
I just paid 200.00 for just what you did