How To Quadrajet Carburetor Rebuild - Part 3 - Tuning
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- čas přidán 12. 08. 2019
- Part 1 - Disassembly: • How To Quadrajet Carbu...
Part 2 - Assembly: • How To Quadrajet Carbu...
Part 3 - Tuning: You're Here Now
Carb Kit from Mike’s Carburetor Parts: www.carburetor-parts.com/
shoptoolreviews.com
So the Quadrajet is back together and ready for tuning. This is a pretty easy process that only requires a straight-slot screwdriver and a vacuum gauge. If you don't have a vacuum gauge, you can pick one up for about $20. Quadrajet tuning shouldn't be intimidating.
If you haven't seen the first two videos in the How To Quadrajet Rebuild, make sure you check them out. The links are above. - Auta a dopravní prostředky
No 'music' no bs, to the point, good video.
Thank you very much.
I agree 1000%
I can’t understand what is being said in many videos because of the background music. I just skip over them.
That was hands-down the best rebuild video I have found all the rest of them skip over things go too fast and are unclear this man was very clear on everything he didn’t go into irrelevant rants he didn’t have loud background music playing while you’re trying to concentrate I rarely subscribe to anything but I did subscribe to this one great job thank you and God bless
This is exactly the video I needed! Going to tune up my 350 Small Block tomorrow. I finally understand the process now, haha. Thanks a million for taking the time to make this video!
What about the choke vacuum break (pull off) adjustment also a very important choke adjustment. Oh and fast idle.
Thank you! Informative, straightforward, and clear tuning to demystify the QJet. Keep it up! Looking forward to more videos.
Excellent video series on how to set up the RQJ correctly. Pretty much to the point, good explanations that make it easy to follow step by step. Welll done, thanks.
Great video! Very informative and explained where everyone understands and very well displayed.
This quality info couldn't have come at a better time! Thank you!
Awesome! Glad that we could help.
A simple, easily-understood, informational vid. that I've been looking for! Though what IS omitted here, is that after max. vacuum is attained, adjust the idle speed screw to the proper RPM, AFTER plugging the PCV hose back on to the carburetor.
Hey Tim, thanks for great instruction. I'm rebuilding a 17080206 quadrajet. Everything I'm learning about vacuum ports metered vacuum and manifold vacuum, pullover enrichment tubes etc, it's all important to me. Thanks!!!
Thankyou for the video, like you say in your bit - I was one of those people that worried about the setup of my Qjet on the 500 in my '74 Caddy Eldorado. Using this vacuum pressure method I was able to improve the running. My engine only had 15 inHg, but after tuning the engine seemed happier and I got it to 19 inHg. I was able to check the operation of the choke and convince myself that isn't causing problems itself too. Unfortunately the Qjet on my engine has lots of stuff crammed around it, AC compressor is butted right up against the front of the carb, so a very thing and long screwdriver is needed for the left side, and as horter stubby one is needed for the right hand side. There is no chance of pulling the manifold vacuum from the front PCV port as that is completely obstructed, so i used the disconnected line from the air cleaner temperature valve. The choke on the Eldo has 2 other vacuum solenoids on it, and the coil is buried in the top of the manifold, requiring the carb to come off to reach! fortunately i think i'm all good. Anyway - I wanted to say thanks for demystifying this for me, the shop manual description was daunting!
The best video! Very concise, straight to the point. 👍
Thank you very much, excellent video, I’ll be rebuilding my quadrajet next week, exactly the tutorial I needed, from Yass NSW Australia 👍🏼
Man this was needed.
Thanks for sharing your knowledge ✌️ Blessings and more blessings to you and your family
Thanks for watching and for your kind words.
Hey Tim, thank you so much for the quick and straight forward explanation for tuning a 4mv Quadra jet carb.
I’m off to the store for a vacuum gauge to fine tune my manifold vacuum.
Thanks again, and I look forward to watching more videos. -RPA
Great video series! QJets got an undeserved bad rap. I think that's because there were SO many of them made, and people would abuse them, or let them sit with gas in them, so there were lots of anecdotes of people thinking their dirty carburetor was a piece of junk. Carburetors are pretty complex pieces of precision machinery. Also, they had to comply with emissions regulations later in their life span - not Rochester's fault, they just had to adjust to keep manufacturing them. As mechanical devices they do wear out and will require periodic repair/rebuilding. This is one of the best video series for instructing you how to do it yourself.
Great video! Took the carb adjustment fear straight out of me! Thanks!
This is the best video I have found explaining how to properly tune a q-jet. This is what I was looking for. I installed a q-jet on my 76 GMC K25 a few months back and have never felt it is tuned right. Found out it was the electronic choke setup at temp. I had never checked that. I still have my old carb and intend on using your other videos to rebuild it.
Perfect! I now have the confidence to properly adjust my Qjet. Note* My jets are the Double D style which I found the proper tool online, Thexton 350 Carburetor Adjusting Tool. My fast idle takes a 1/4" 90 degree to get to.
Absolutley fantastic series! I just bought a used q-jet and i will rebuild it before i put it in the car. And these videos made med less nervous to take this thing apart! Thank you so much!! 😃
Glad I could help! Thanks for letting us know. Thanks for watching.
Brilliant, thank you very much!
Needed this to get back in control of my warm 253/4.2L 1980 Holden Panel Van
You're a lifesaver
Best video ever. Love it because it’s well explained!! Thank you
Great explanation. Especially about the straight vacuum! I just used the vacuum for the distributor. Thank you!
Thanks for watching.
Awesome. I have a 1970 454 Corvette and wanted to "tune" the Quadrajet. I'm no mechanic but this was so helpful. Thanks.
Thank you for this video. It really did helped get my 87 olds 442 running smooth and 💪🏼 again.
That is really great to hear. '87 442, that's awesome. You still have the stock 307? Those G bodies are becoming tougher and tougher to find. Thanks for watching and commenting.
Yup 307 and it looks like a plate of spaghetti 🍝 under the hood with all those vacuum hoses. I was thinking of swapping the engine for a GM Erod set up just because of the emissions here California. Poor car needs more horsepower to do justice for how it looks. Thanks again for your detail information on quadrajets.
Thanks i will return to your videos 1,2,3 after i get my Chevelle back from paint..I'm experimenting with stock 396 manifold and an airgap.
Thank you so much for these videos. I renovated my Volvo Penta V8 this winter, and could not get it to run. People told me to either let a profesional look at my carb, or buy a new one, both very costly options. But i like to try to do things myself, so i got a service-kit and followed these videos. Today i reinstalled the carb and the engine performed great! The only issue left is idle (Did not have a vacuum gauge on hand)
Extremely well explained. I have a 76 Eldorado convertible with 48K original that sat in a garage for over 25 years and it has been way too many years since I fooled around with carburetors. It is very hard to start if you do not prime it. So after watching it is clear that I am leaking gas internally. I knew I was getting drain out, since the clear fuel filter was always empty after sitting over night. I did buy an inline check ball to install in the fuel line until I can rebuild it correctly. Again thanks so much, Very well done!
I didn’t have a dad growing up so that’s why I’m here thank you for the great video 😂
Glad you enjoyed! Thanks for watching.
Just bought a vacuum gauge, great video, fixing to go work on my 1972 chevy truck! Thanks!
Awesome, hope it works well for you. Thanks for watching.
This just got me out of a mess at the shop. Thank you for the refresher on carbs.
Awesome, so glad it helped you. Thanks for watching.
What a great video. Informative and simple. You made me a hero. I'm dialing in twin Rochester quadrajets on a friends 1966 Chris Craft Commander using this info.
Best video on the internet your very Thorough eye contact with camera use hands and guide the whole way very very good explanation.some mechanics are very condescending when they talk and arrogant thankyou you literally just saved me a ton of money
Great job walking us through . I gained a better understanding for sure .
this helped me get my 55 Packard tuned up and running like new..............THANK YOU !!!!
I've got a motorhome with the Quad and 454. Great video!!! Too bad the idle screws are so hard to get to in a MH because of all the AIR system components and such. Glad to have found this one!
Thank you. Ugh! Motorhome can be a pain to work around sometimes. Hopefully, you can get her dialed in quick. Thanks for watching and commenting.
Great video, super helpful and shows where the screws are and what you need. Very helpful vid👍👍
Thank you very much. Glad it helped.
I'm glad I watched your video. Very informative without too much jaw-jacking.
this is the video i've been looking for...now i understand how and why to turn the screws...thanks million!!!
I would like to extend an EXTREMELY greatful thank you, have to adjust the Quadrajet on my 88 Dodge B350 thats idling high and my dad couldn't help. With this video under my belt I found the screw I needed in literally less then 10 seconds.
It's so great to hear this. I'm excited that you were able to benefit from our videos. Thank you for the feedback.
I believe the Dodge has a different carburetor. It should be a Carter Thermoquad. That carburetor has a black plastic main body. Really different design. Try watching this guys video.
czcams.com/video/1pIEpV4PyvA/video.html
@@Ed70Nova427 mine has a Carter Quadrajet. Thank you for the info though as im only 25 and dont know much about carbs. The only reason i know what mine is is because it was written on the side
Chris Cary aaah ok. I guess someone installed it as a modification. I believe the Carter Quadrajet is a pre 1968 carb manufactured under license of Rochester. I have never seen one factory installed on a Chrysler product. But that doesn’t mean it didn’t happen.
@@Ed70Nova427 clearly you know a lot more about carbs then i do, i will say that I'm not sure which one but i do believe i have a special 5.9L as it has extra "coolant" lines (I'm not 100% they're coolant but that seems the most likely due to size and location) that i havent seen on another 360
Amazing video! I knew my choke didn’t work I just didn’t know why. Mine is wide open all the time
Thanks for the tip on using the PCV port for vacuum! From now on, I will use that source instead of a fitting on the back of the intake manifold.
they're both manifold vacuum lol. You're not getting ported air from the intake manifold
@@dansmith6990 I don't want ported.
I am getting a 1978 L82 Corvette with a quadrajet carburetor barn find going, it sat for 8 years. This is how everyone on youtube should do an instructional video. Thanks and Cheers, Jim
That's awesome. Those era Corvettes were forgotten about for years, and I'm glad to see they're finally becoming "cool" to restore now. Sure, they were low horsepower, but they still represented an era. Thank you very much for the kudos. Let us know about your L82 rebuild.
Thank you so much for this information sir. This is an absolute life saver!
You're very welcome! So glad that it was helpful. Thank you for watching and thank you for the comment.
These videos are absolute gold! So informative and easy to follow. Really appreciate you making these!
Glad you like them! Thanks for taking the time to reply.
Thnx alot. Just got mine rebuilt. Needs a tweaking. Now it runs perfect
Awesome and easy to understand video. I just bought a quadrajet stage 1 from Summit Racing and I'm pulling my hair out trying to understand why my choke blade only opens to approximately 45° with fully warm engine. If I push down on the step cam it goes to 90° and stays there. But it won't do it on it's own. I called Summit tech support who suggested that I wasn't getting 12 volts to the choke spring. I replaced my factory connector and put a new 20 amp fuse in still not opening fully. I called Jet performance who rebuilt this quadrajet and left 2 messages for tech who hasn't returned my calls which is probably the pandemic. It sucks to pay $488 for a rebuilt carburetor and have to mess around trying to get a choke blade to fully open! I adjusted the air screws exactly as you described and when I manually push the step cam down the old k10 runs awesome. Not really into carrying a stool and pulling an air cleaner every time I go somewhere. Keep in mind that this truck is my daily driver. Please tell me that you've dealt with this and hopefully you can suggest what is going on. Thanks
Wow this guy is so clear and detailed.
Buddy, you explained this so good, thank you
Landon Roy thank you for the compliment
Great series of videos. Thank you so much. Great explanations and filming.
Thanks for watching!
A friend asked me to help him rebuild his Qjet and since I haven't touched one since the 70s I came to CZcams for a good How-To. I found if not the best, then certainly one of the best here. As a totally unexpected and very much appreciated bonus you also solved a problem I have with my motorhome (I live in it fulltime) which has a QJet on a 454 BBC. After it sits for a while (short while not months or years) it will not start unless the carb is primed. Total PITA to have to move all my stuff and remove the doghouse cover to do so. Now I know what the problem is and can easily fix it which makes my life so much easier. Thank you for sharing your knowledge and experience.
I truly appreciate your feedback and I am sincerely humbled. It's so gratifying to know that someone is actually benefitting from our videos.
Subscribed....... .
Thanks for the tips. I've been working on my 80 K5 Blazer and learning more about my Quadrajet carburetor this also helps
Awesome, thank you!
This video is hold to any car guy!! Thankyou 🤟
Gold moter there, nice! ;) And, good job on the carb. People need to learn the quadrajet and this will be helpful.
Thanks 👍. Gold motor is original Oldsmobilt Rocket 350 gold.
Right on, this was great. I just got an 85 Ramcharger with QJ on it. Never seen anyone tune a carb with a Vac gage, I'll give it a go.
Take your time and you should be good. Thanks for watching.
Good video, and well explained. I always use a timing light when adjusting a carburetor. I have 5 Q-jets on the shelf in my shop. When I go to a junkyard and see one i pick it up. When I worked for Chevrolet I got alot of rebuild time.
Thank you. What were you looking for with the timing light when tuning the carb? We understand what you mean about collecting Q-jets as you find them. It's nice to have a clean one built and ready to go. A quick way to diagnose issues on other motors. Did you work on fuel systems at Chevy?
@@Shoptoolreviews I was taught to make sure the timing was in, everytime a Carb adjustment or rebuild was done. Cause correct timing gives good throttle response and helps with a smooth idle. I'm retired from Automotive now but I was fortunate to work in the age of Carburetors. And the information I learned from my elders was enormous. You covered a lot more than most videos have, You have have 3 part. Most are 1 short packed hit and miss.
Lou Shackelford that makes total sense. I thought you were using the timing light as a tuning measure for the carb. I’ve been blessed to have my father and his friends that were racers in the 60s and 70s. One particular is pretty much a genius when it comes to understanding combustion engines. I’ve done my best to sponge as much information as possible.
@@Shoptoolreviews My father drove and worked on his own racecar and I was his shadow. My dad's racing buddy was a Chevrolet master tech, and got me a job working for Chevrolet and taught me so much. I still turn wrenches some times and love old Points Distributor, HEI Distributor and Carburetor engines. What I feel is a lost art when working on cars. Have you ever done the Nickel balance on a Carburetor?
Thanks for the great lesson. I think I’ll go out and buy a vacuum gauge.
Excellent video buddy I definitely subscribed to your channel. Thanks for the video.
Damn! Bout time, thank you guys!!
Better late than never. :)
Awesome video! Very informative!
Good video. The last time i😂 rebuilt one of these, other than this one, was in 1989. Had to rely on memory and a print. It's alot easier with you tube. Thanks
You gave me some very good information, and easy to understand Thank You.
Glad it was helpful! Thanks for watching.
Great presentation! Thank you very much!!
thanks a lot that helps me a lot with my 71 buick gs 350 quadrajet
Awesome video and knowledge, thank you
Great vid. Very useful. Greetings from Poland.
Nicely explained, thank you!
Very useful and clearly presented explanation.
Glad it was helpful! Thanks for watching.
Awesome video!! Thanks so much!
Learned something new thanks very much my man super great video
Glad you enjoyed it. We really appreciate you watching and commenting.
I just ordered my rebuild kit. Thanks. I can do this.
Did you get your carburetor rebuilt?
Everyone, do yourself a favor and buy a rebuild kit from Cliffs High Performance. Believe me, wish I had the 1st time. That new power piston collar is the bee's knees.
Great videos. Much appreciated!
Thanks for this video was very helpful
Very good "simplification" of preliminary QJ adjustments. Easy to understand, and no distractions.
I would add some info to the choke system, the pull-off, or vacuum break.
Not really an adjustment "per-se" but an influence to the choke spring adjustment. Once the eng. is started, it should crack open the choke valve.
And for the hot-rodders, the secondary air valve adj. is critical to elimination of the famous "quadre-bog" that has plagued the reputation of this fine carburetor.
And lastly, setting the mixture screws for highest vacuum, has always given my street Pontiac V-8s, a lean stumble or minor surge. After finding your sweet spot, I always back them out a 1/2 turn or so more.
Yes, you are correct, there is still more in the QJ tuning arena than what we covered. We were really trying to stay in the confines of "teaching" someone new to tune their carb. There are still plenty of you out there that surpass my QJ knowledge. Thanks for watching.
By max vacuum, are we talking about the gauge going counter clockwise to it's max reading?
@@ourkid2000 There's numbers on your gauge Chris. Depending on variables, you could be idling as high as 20+"s, or less than 15"s. Not sure what you're using for a gauge.
Great job on the video!!
Thank you!
Awesome,..great info. Cheers Guys!
Yeah I like this video... good solid info. And no bs for entertaining purposes 😏 I was entertained the whole video good job give us more
All my life I have never heard "straight-slot" screwdriver, I've been calling it a flat-head all my life lol
TheDuck8185 flat-head, straight-slot, slotted, ancient, they’re all the same. 😁
@@Shoptoolreviews Thanks for the great video!
I agree that when you hear SLOT or FLAT when talking about a screwdriver, everyone knows what you mean.
Not true for the screw itself which even though all can be straight-slot,
the actual head of the screw can be a multitude of different types (Flat head, Oval head, Machine head, etc en.wikipedia.org/wiki/Screw#Hex_cap_screws )
2Truth4Liberty I’ve always called it a standard Or when someone says this one , I call it (that’s it ! )
How about criss cross ?
It's just always been "screwdriver" . Anything else was called by its fancy name- phillips, torx, etc
The best I've seen.
Thanks for the vid! Helped me alot
Glad it helped!
Good useable info in your videos 👍🇺🇸👍
Best video I've seen on this.
Wow, thanks! Thanks for watching.
Fantastic and Amazing tech Video.. exactly what I need...!!!
Thanhs😮
The heads are 8, no HEI distributor-running points (I want to keep factory appearance), and I have a large cam on an original 72 motor. What type of intake gasket should I use? What is the largest cam? You have the BEST videos! I appreciate all of your help!
Good tutorial!
Excellent video!
Thank you very much!
Excellent video.
Thank you very much!
Now I can try it for sure. 1974 Corvette will finally run right.
Awesome. Go fot it! This should definitely help, and thanks for watching.
Great video. Thank you!
OUTSTANDING BRO!!! I HAVE A 1970 OLDS 442-W-30 WITH A CARB # 7040258 .. A RARE CARB..
Yes, if you have a '70 W30 carb, that's a good one to have. Let us know if you ever want to sell it.
Why would you want to buy it??? Is there something special about it??@@Shoptoolreviews
Good video!
Great videos, Sir. Many thanks.
Thank you very much.
Best video by far!
Thank you very much. Thanks for watching.
Great videos!!
Informative thanks tim
very detailed video,, good job new member
I wish you would have covered the spring tension adjustment on the secondary. But great video. I needed a refresher and the video was informative. Thank you
great video i learned alot.
So Good.
Thank You! 🙏🙏🙏🙏🙏
Great video!
It's been many years since I rebuilt the 4 barrel Quadrajet carb on the 350 Chevy engine that came in a '72 Chevy Cheyenne pickup that I was restoring, around the year 2000. I believe (if I remember correctly) that this carb was slightly different than the one in your video. I think it had what they called a stove choke where a little metal housing screwed to the exhaust manifold and the spiral operating spring was inside the housing (stove) which operated the linkage that opened up the choke plate as the exhaust manifold heated up. Also, I remember my carburetor had a screw which adjusted a spring to change the spring tension that determined when the secondaries would open up depending on what the engine called for or wanted. This spring could be adjusted to allow the secondaries to open sooner or later depending on engine demand or to explain it a different way you could adjust the secondaries to open sooner as long as the engine didn't stumble upon opening and if it did you could tighten the spring tension to allow the secondaries to open later and get rid of the stumble, adjusting it to whatever made the engine run happy. 😜
This adjustment was useful for tuning an engine that might have been built with a mild camshaft or even something more radical and also what type of exhaust you were running like headers, hi-flow mufflers etc etc since engine demand and hence air/fuel demand changes depending on how an engine is built, what kind of accessories it's running etc etc.
Anyway, I noticed that your carburetor either didn't have this adjustment or you just didn't cover it in this video but I'm curious if it didn't why that is and if you've ever dialed a carburetor in that does have this adjustment and what your thoughts and opinions are of them.
Hey Jeff thanks for mentioning that I have a 71 Winnebago motorhome with that same carb with a 454 I’m sure glad you mentioned that And how to tune it great info thank you sir and God bless you
Hey Jeff thanks for mentioning that I have a 71 Winnebago motorhome with that same carb with a 454 I’m sure glad you mentioned that And how to tune it great info thank you sir and God bless you
@@ronmurphy00 Glad I could help, thank you and God bless 🙏