Troubleshooting a Porsche 944 No-Start Condition
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- čas přidán 25. 07. 2024
- In this video I show you how to troubleshoot some of the most common no start issues on a Porsche 944. In most cases the DME or fuel pump relay will be at fault which is why you should always carry a spare. However, in some cases you may find that you don't have tach bounce when turning the engine over. If that occurs you can check the reference sensor using the steps in the video. While this may not cover every no-start condition, this should give you an idea of where to look!
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Tags: Porsche, 944, 924, 924S, repair, rebuild, engine, project - Auta a dopravní prostředky
I'm seriously considering the purchase of a 944 and I've watched nearly all of your videos as a reference point for some common issues I read about. I've never seen someone be as detailed and informative in their how to videos as you. Thanks so much for the efforts and the information you provide. I just subscribed and liked all your videos. Thanks again.
Thanks! Good luck with your search!
Hi !
You just saved my day mate, my European, Swedish sold 944 from the first production year 1982 just stopped on me the other day.
I watched your videos before so I just tuned in again and followed your instructions and it turned out my reference sensor was bad 👍
Now it runs like a charm again thanks to your helpfull video, hats of to you bro !!
Many thanks from Sweden !!
Fantastic videos, you've taught me nearly as much about my 924S than I've learned in the 18 years I've been driving it, Thanks!
5 years later and this video was super helpful! Both of my sensor wire connectors were completely degraded! Like half of the plastic that surrounds the metal was missing. Gonna order some new ones and I’ll be back to driving the beast!
You’ve saved me on my 84 944 so many times lol, I don’t think anyone has as much 944 info out there as you
No problem! If you like my videos be sure to share them! I rely on viewers that enjoy them to tell others rather than me spamming them. Thanks!
Same here! Got mine working again today!!! THANK YOU!!!
sorry to be offtopic but does someone know a method to log back into an Instagram account?
I was stupid forgot the password. I love any tips you can offer me.
@Gannon Graysen instablaster ;)
Starting work on our 944. This will be a great reference video. Thank you for these videos
Many thanks for a great diagnostic video. I used your advice and was able to rectify sensor failure in my 85 944 2.5. This is a brilliant video with the perfect advice to diagnose and rectify the failure to start. You really saved my life. Cheers and keep posting these great tips. Your a legend matey.
Thanks! I'm glad it was able to help you get it sorted!
Your video are very good.keep up it up. I am learning so much from your videos.
Thanks for taking time time to make them.
Thanks for the video! My car is alive again! The only thing different I did was to put a little anti-seize on the sides of the reference sensors so that they would drop in easier.
Thank you so much for your videos. We just got an 88 944 turbo that runs but needs a little tlc. I knew nothing about German cars, but now I do.
Having a no start on my 1984 Porsche 944, going to try this tonight and see what happens. Thanks for the help
Great video! Clear and concise. Thanks! I just met a guy today with an 83 944 that has the water pump froze up and he is getting ready to change the pump and timing belts. Very nice car with 34 thousand miles showing on the odometer! Thanks again!!
No problem, thanks for watching!
I just did a video about the same issue yesterday. Great video! Very nice explanation. So glad there is another guy out there explaining things so simply! I subscribed 👍
Thanks for subscribing! Nice to see a fellow youtuber working on these cars. Glad you got yours fixed! I was just telling someone the other day that the DME won't start the fuel pump without seeing a signal from these sensors. So its nice to see this information getting out there so that can actually help people!
edredas yes sir!
If. Just starts with fuel spray whats gonna be wrong. Fatherlawn have one on garage he no have clue whats goin on
Thanks man. You just saved me a ton of money! It was the DME relay for me.
Great video and very helpful. I've had an intermittant problem with my 924S for the last 8 years and no one has been able to fix it... I did after watching this video!
My problem was that the car was not starting when the engine was hot and had been standing for about 40 minutes, lifting the hood for a while to let things cool down seemed to resolve the issue. Yesterday I disconnected the speed and reference sensors, sprayed the contacts with WD40 and reconnected them. The problem appears to be resolved!
Thank you Edredas :)
Awesome! Glad you got it sorted!
Good real world diagnostics. Great job thanks
nice job again, you are a big help in keeping alot of these 944s on the road!
I have 3 944's one I've owned since 92.
I do all my own work and have learned some things the hard way.
These videos are very very useful and worth watching.
Thank you!
I got a 944 up and running after sitting for 20 years! It had a bad DME relay, reference sensor, and clogged injectors.
Ive been looking for a video like this to help me with my 86 944. Thanks and subbed!
Awesome! Thanks for subscribing!
Thanks for all you help to us master u the greatest tutorials videos you always make I have a question is anyway to know what kind of dme unit use my car I buy a 1985 944 comes with one unit I buy another one same numbers and doesn’t work but I try another with different numbers and the car runs it is right maybe they Swaap the ecu before ?
Thank you for this video edredas
! I'm having the same issue with my 85 1/2 944. Weird thing is Gas was pretty much fumes a few weeks ago so after letting it sit for a few weeks I added some gas and it started right up. Then again it sat for a few weeks on the battery retainer and here we go again no start and healthy crank. I'm going to follow your methods and order a few of those parts to have on me and for spare. You made it sounds simple enough to troubleshoot and saved me a few 100 while sitting in a shop for a few days. So I'll let you know if I get it up and running. adding on FB thank you!
Awesome! Good luck!
The reference sensor is deep though. It's a pain in the ass to remove. But you gave me a clue what's next. I was about to change the fuel pump instead.
great vid. keep up the good work.i enjoy all your vids.
Thanks!
edredas with the sensor plug notch up .which two contacts do you use tester on ?
Hi, I was just helping someone with their no-start condition and noticed this post. I know its old but I always try to reply to every comment. The way youtube works is that it only puts new comments in my feed so I often miss replies. I don't know why they don't fix it. That said, with the notch up then you would use the Left and Center contacts.
This is hands down the best no start video. However now I'm dealing with a different car that starts fine but wont idle. It would be awesome to see a video on that!
Thanks! If its stalling then make sure all the vacuum lines are connected tightly and that the air flow meter is plugged in. Any leaks will cause it to stall. There's one particular hose that always seems to be forgotten underneath the intake so be sure to check that. If everything looks good then check the fuel pressure at the rail, since a bad fuel pressure regulator can also cause the car not to idle. Good luck!
@@edredas thanks for the recommendation! Yea I suspect a vacuum leak but I didnt know fpr could cause that.
This is great information. Thanks so much!
Great Video - Thanks!
awesome video! right to the point thank you!!
Cool. I had an '87 924S do the same thing.
We had these same symptoms and many of the tests pointed to faulty relay, pump relay, crank sensor, etc. issue was bad solder connections on the Motronic DME/ECU. Bought a supposed rebuilt DME/ECU same no start condition. Took to specialist and they narrowed it down to the DME/ECU by using a blow dryer or heat gun to warm up the DME/ECU (hunch based on the fact that we had replaced everything else and that we had last drove the 924S during a hot summer day) Another rebuild DME/ECU and everything worked fine. IMHO these boxes are getting so old that you can’t assume that they work fine and measuring voltages elsewhere with a bad DME/ECU can give spurious results.
Very helpful video. Im looking at a very mint 944 that they only want a couple grand for, but its having a no start issue ill have to look more in depth about this later.
I'm sure you've already decided on the car. But I wanna say that when I bought my first 944 the PO said he couldn't get it to start after 2 years of paying mechanics. I watched this video and it gave me the confidence to go ahead and buy the car. 15 minutes after purchasing it was running like a singer sewing machine
@@jmccoy96jm i wasnt able to get it bought before the kid got under the car and connected his ground to his newly installed fuel pump
My 85 had a loose connection on the crank reference sensor, it was an easy fix after checking forums for tips but, I wouldn't have found it on my own.
Bam! It starts again. Great video!
Awesome! Thanks!
GD....I'm watching everything cuz this guy is a phenomenal mechanic & CZcams producer!!! When are u gonna start live events????? Thank u for great vids !!!!
Glad you enjoy the videos! I sometimes do live events on my facebook page and take questions. I don't do it often but I do try to update the page frequently, so be sure to join me there and in the group! Thanks!
@@edredas Will Do! PS...my 924s is exactly like yours!!! Looking to get a 944...and the plan is to get you to restore it! I'm in NH, so likely but down there & drive it back!!!
I have the hot no start issue, Will have to check sensor and harness when the car is warmed up, cold everything is fine...Thanks for posting!
Good luck! Let me know what you find! That white '88 944 that I did a video on is now having a hot-start issue and I haven't had time to diagnose it. I've been told that it will only run for about 10-15 seconds and then the fuel pressure shoots way up and dies.
well, my first guess is a vaccum problem that lets the FPR "close" the return and pressure spikes leading to a too rich condition. my issue is after engine is varm (20 minutes of driving or so) I can't start it until it cools down, pressure is fine so I think it is electrical, Have to check tacho bounce next time I start to see if it is a speed sensor problem or harness or connector. Occasionally it can be the ign.coil...but that is rare.
Good job. Almost comical that these problems are so common that you suggest carrying spare relays, sensors and DME, but thanks for the info!
Yup, well they're 30+ year old parts at this point so they're bound to fail at this age. Once they're replaced you should be fine, but original parts were never meant to last this long...
I really appreciate all your videos! I certainly enjoy working on my 1986 944, I've save a lot of money! Can you do a video in how to adjust your tie rods?
Thank You!
I show how to replace the tie rods and adjust them in one of the videos I made on the 1984 Silver 944. I then had it aligned professionally. I hope that helps!
Tips 100% helpful
Thanks, I'm going to try and do a few more videos like this!
Great video! Thank you for sharing. New subscriber!
Thanks! Glad to have you as a subscriber!
Thank you! Hopefully you’ll subscribe to my channel once I post my sweet 83’ 944. Take care!
Good video. It mentions about having a phillips screw driver in the car and extra fuel relay. Where exactly is the screw, screws to remove top fuse section?
Thanks for this video
No problem! I hope it helps!
Great content! Have you ever come across a cold start idling issue with any 944? Mine is a 1985 and only is rough on cold start. Once warm no longer an issue. Any ideas you can share would be great.
Try looking around for any vacuum leaks. These can cause the car to run poorly when cold. I hope that helps!
if you have a stuck sensor...i used a set of 15'' long nose locking pliers- worked great for both sensors-took about 20min extra on the rear sensor with penetrating oil and patience...
great video thanks. I am not a great fan of Bosch injections system they are not very reliable(?)I have always had loads of problems with mine on my peugeot 309 sri. (same as 205gti 1.6i) Your engine sounds much nicer than mine also.
Hey your help was absolutely a huge benefit to me . Up and running . I have another question if you can help . The stock tires all the way around on this 1984 944 are 215 60 15 . Would you know how much wider of a tire I could put on the stock rims safely ? I just think it would look better . Again , your help is what put this back on the road . I have to buy new tires because I bought this in the winter initially and put studded tires on because I bought this for my son to learn to drive a stick.
Awesome! As far as tires go I have seen N/A cars with 225/60 on them. You might be able to go up to 255 in the rear but not so sure that those will fit on the front. I have personally only used the stock sizes on my cars, so apologies for not being any more help than that. Thanks!
Very helpful!
Good afternoon, I am in a fix, I purchased a 1984 944 back in 2015, it was running and doing great, that December I had it painted and was slowly putting all of the parts back on it when my house flooded and had to move so I put the car in storage in a warehouse for about 2 years, when I was moving it to my house it would not start and had to have it towed to my house in 2017, well like John Lennon said , Live is what happens to you when your busy making other plans, I have decided to get it back on the road, I put a new battery in and when I put the key in the switch the bells go off and I have blinkers, headlights light but they do not open, gauges move and nothing else, I have worked on American and British cars since 1975 but this is my first German car, any suggestions on what to try next, maybe fuses or relays to check anything help would be appreciated. Thanks Chuck
My 86 951 loves you dude.
Great Video
Had to remove the holder as the B sensor was so corroded that it would not come out
One question - is it the B sensor or the D sensor that has to be gapped if you remove the holder
Its not clear on your video?
I love your videos, they are my go to when I have an issue. I am however struggling with an issue on my 86 924s . When I remove my key the engine continues to run as normal. I've swapped the ignition switch and DME relay any ideas? Thanks in advance.
Is it dieseling, where as its a run on condition where there is knocking associated? This isn't common in a gasoline engine but I've seen it before. Or is it as if the switch is still on? If its the latter then it isn't terribly uncommon for the wiring to be mucked with in these cars. So the only thing that I can think of is that perhaps there is a short somewhere in the ignition switch wiring. Many times people do not realize that the fuel pump will only kick on once the computer recognizes that the engine is being turned over as a safety feature. This prevents the fuel pump from continuing the run in a situation where the fuel lines have severed. The engine would stop running in that case and cut the fuel pump off, but many "mechanics" will circumvent this because the think that the fuel pump isn't working because it does nothing when the turn the key. This not only causes an issue that can be very dangerous but can also keep the car running after the key is removed if it is done poorly. I hope that helps!
@@edredas Hey buddy, I figured it out. I replaced all my dash bulbs with LEDs, including the battery/alternator indicator light. I was getting current back feed from the alternator with the LED in in that bulb holder. I swapped back to the original glass bulb and hey presto, problem solved.
Thanks for the video. It´s very helpful. One question: Your dashboard looks like an older model (1985 or prior). Are you shure its a 1988?
It's an '88 924S so it has the early interior but has a 944 engine. Thanks!
I have a 944S2 which refused to Start. Tried the all the advised stuff, spark at plugs, cylinder pressure, fuel pressure, sensors etc. It turned out to be the fuel damper, a part no longer available new. Had to find a salvage one. Fine starting after that.
Bought a 1984 944 automatic about a month ago and am finally getting work done to it. She will not crank by key, but I have heard the car run with the old screwdriver across the starter trick. Starter is getting power, but nothing when I hit the key. After finding and replacing/repairing all sorts of corrosion around the fuse boxes and many wrong fuses, still a no start by key. Replaced the ignition switch and nothing. I'm thinking a new starter solenoid, but I am not sure. Close to pulling the trigger on a new starter anyways... Any suggestions? The car has all sorts of aftermarket junk like a radio and some sort of "scosche" relay wired to the starter that I removed because it was rusted out. Thank you for any help! I cant wait to get my car on the road.
If the starter works when you jump it, then its likely not getting power from the ignition switch. Make sure that you have continuity from the switch to the small wire on the starter. I hope that helps!
I have a 1983 944 but I’ve checked the sensor but they read good around 800 ohms but had high resistance in my ignition coil an don’t have tach bounce.
The wiring at the the sensors on the car side are notorious for breaking. If you have tested the sensor readings at the DME plug to verify the wiring is good then its possible the DME is the problem. There are solder joints inside the DME that sometimes get hot often because a high resistance at the coil. I should probably make a video on repairing this issue but if you are brave enough you can take the DME apart and resolder the joints.
Hey sir I enjoy your videos as much as I enjoy my Porsche 944 and it wont start only when starting fluid is sprayed it tries and the tachometer bounce a second then cuts but wont start I haven't tried jumping the relay to see if thats it but I can do that next weekend I guess and it has spark to every cylinder I just was able to get crankshaft reference sensors reading to tach now but wont stay running if it tries to and then boggs out with starting fluid maybe the computer isnt working right or maybe the DME relay I switched in got hot and burnt up and maybe need another one idk I do know I miss my car
Sounds like you aren't getting fuel. If your DME relay is getting hot then it could be the relay is bad or there is a short somewhere. You may need to check the resistance or jump the DME relay to verify the pump is running.
I will check that out thank you sir you are a great man
super sympas merci bien expliquer
Hey I’m having a no start issue as well on my 1978 924, I’ve replaced the faulty ignition coil (resistance measurements were off spec) however still no start, but I’ve noticed there’s 2 ballast resistors before the coil wich take the voltage down, I’ve measured them and the 1st one takes the voltage down from 12v to 8v and the 2nd one takes it down from that 8v to like 5.4V. This seems strange to me, as people say the coil needs 12v, do you think I should remove those resistors?
Hi, its been forever since I've worked on an original 2.0L 924. I believe you can bypass the resistor and try to fire up the car just to see if it runs. That said, check out 924board.org. They are a great group of guys that know everything about those cars and should be able to get you going! I hope that helps!
Awesome!
Thanks
With just the ignition on and new relay and DEE should I be able to get voltage at the fuel pump ? 1984 944 . I am not getting voltage.
The only time you will have voltage at the fuel pump is when the engine is being turned over by the starter or when running. This prevents the pump from pouring fuel onto the ground in the event the engine has stopped because of an accident with the fuel lines severed.
Try using a jumper in the DME relay socket and checking for voltage that way. I hope that help!
Hi my 1990 3,0L s2 is turning over, with no Tach bounce, had new DME relay, Ref sensor, only one on this model, and ECU tested fine. Have power to both sides of the coil but no spark and only pumps fuel when I bypass relay. Could the final stage amplifier module stopping tach bounce? or any ideas please?
I'm not sure if the signal amplifier has anything to do with tach bounce but there's a very good chance that it does. I've only worked on a few of them and the were later S2/968's without them. I hope that helps!
Thanks a lot. My 1991 S2 revs terribly. If i press the throtle normaly almost nothing happens but if i press it very slowly ir gets better!
And normaly slowing down in the same gear, below 2000 revs ir produces small explosions...!
...Any suggestion!
Thanks a lot.
Sounds like you could have some vacuum leaks.
@@edredas Thanks, but no. Accidentally, i've found the problem. It was a bad pluged conector in the Mass Meter. I spent more than a half year with this, changing things in the engine and it was only that. Now its great again. Thank you all.
Hey so I’m dealing with a no start. I’ve swapped DMEs, relays, coil packs, new hall sensors, new hall sensor harness from LR, I tested 26-27 after the new harness and still have OL. I’m not sure where to go from here. Maybe a ground issue?
Check the continuity of each wire at the plug end to the DME plug for greater accuracy. I find that works a lot better. Good luck!
With my 944 my sensors are reading just over 1000 ohms and I don't have tach bounce nor any lights on the dash and the red light on my dash if off could it be the immobiliser or the dme ? Any help would be appreciated
Sounds like you're on track. Hard to say which it could be without doing some troubleshooting. I believe Clarks garage has a write up on jumping the alarm/immobilizer. I would try that first then I would try a different DME. I hope that helps!
Master do u think is the reason for my oil smell to much of gas my dme is 944.618.111.01 with that one start for 10 seconds and die the car and has be disconnected the dme temperature sensor to start new sensor but I found a new dme unit with different number is 944.618.121.05 and I think that one is for 924 87 and up my is 1985 944 any help thanks for take the time master
If your car is only starting with the DME temp sensor unplugged then you have a vacuum leak. Unplugging the sensor makes the car run richer to compensate for the extra air, but can also allow too much fuel into the cylinder which can get into the oil. I hope that helps!
i have a problem with my 1983 porsche 944 I have checked the reference and speed sensors, both mark ohms but they do not give voltage when turning on
Interesting. If everything else is showing continuity then the sensors could be bad if they are not outputting any voltage when the engine is turning over. Also be sure to note I think the voltage may not show up on all multimeters since it is a very fast pulse. I hope that helps!
Is it necessary for the bracket that holds the 2 speed sensors to be bolted to the intake manifold for the car to start? I'm having a no start situation.
That bracket just holds the connectors and would not prevent the car from starting.
When this happened do you hear the fuel pump primming?
I have 1986 944 turbo.
I did not hear the fuel pump priming since the original fuel pump relay does not have that feature. With a faulty sensor and original relay you wouldn't hear the pump since the computer controls the pump and doesn't see the engine trying to start. With an aftermarket relay you may hear the pump priming when you turn the switch, but there would still be no spark in this situation. I hope that helps!
I have a 924 with no spark issue can you give me shoot me some info on how to check for it I have new plugs wires cap n rotor getting power and ground but still no spark
What year is your 924? If it's a 924S from 1986-1987 then the wiring is the same as the early 944. Does the power windows work? Power to the coil comes through a plug on A on the back of the fuse box but that is supplied from the switch though a plug on E. If the terminal on E has corroded then you won't have power windows or power getting to the coil. I hope that helps!
I have an 84 944 that I replaced the speed and reference sensors and I still have no tach bounce and no spark. I opened the dme relay and it checked out fine, I opened the dme looking for bad solder joints or opened resistors or burnt components, it looked like brand new. I get 892 ohms on dme plug pins 25 and 26, and 912 ohms on pins 8 and 27 and the readings change when I turn it over. What else should I try?
Looks like the sensor are okay, sometimes the DME joints can crack and its hard to tell. They usually crack around a heat sink on the bottom board and to see it you'll need to remove the bottom plate. Re-soldering this area has repaired many DME's! I hope that helps!
edredas , thanks, I'll try resoldering, in the mean time I ordered a DME from ebay, if the resolder fixes it, at least I will have a spare... and thankyou for your videos, they've been a great help in rebuilding my 944
If you remember me, I'm the guy near Buffalo NY with a 1984 944 that won't start... still... I've found a few wires behind the relay and fuse panels that aren't connected, any idea where they might go? the first is a black/red wire with a bare connector, the next is a 2 wire plug with round holes for the connector one wire is bright greensand the 2nd is bright green with black stripe... there are also 2 wires that have clear long rectangular plastic plug covers, one is white/black stripe and thin, the other has the same type of clear plug end, I cant remember the color of that one... I don't know what else to do to get this thing started.... please help
hey edredas can you send me a link or let me know where you got your multimeter? much appreciated and love the videos!
Thanks! I got the multimeter that's in the video from Lowes for about $30, but I have a bunch of them ranging from $6 to $150. All of them work great but I use them for different purposes since some have features others don't. The one in this video can also find parasitic drain if your battery keeps dying but if you don't use one very often and are just looking to do this job, then I would just get a cheap one from Harbor Freight for a few bucks. They work great and I actually like using it more than the more expensive ones for some simple jobs. Here's a link and I hope that helps!
www.harborfreight.com/7-function-digital-multimeter-63759.html?cid=paid_google|||63759&gclid=EAIaIQobChMIsZHG16a36QIVF6SzCh2sTAq9EAYYASABEgJq4PD_BwE
@@edredas awsome thanks ill try it!!
Great video as always. The only time I had mine not start was with a poor connection to the temp sensor for the DME. The reason being hidden inside the rubber boot of the connector. There the PO had soldered in a 330 ohm resistor that had a leg break off causing the DME to loose contact with the temp sensor. The car would actually be possible to start, with constant full throttle, and run horribly. But was completely dead - not even a hint of ignition - under normal starting conditions. Can you elaborate on the reason for fooling the DME to think the engine is cooler than it really is ?
Glad you got it dunning again. As for the resistor, I have seen a them a few times and it's hard to know whether it was there to add more fuel or if perhaps they are there to cover up another issue. I have also seen aftermarket devices in that location with a variable resistor that are supposed to increase performance but they're snake oil. I hope that helps!
@@edredas Yes, I actually put a pot-meter in there myself, for experimentation. But so far I haven't found any advantages, and the info online is non existing or at very best shallow. You can find this kind of mod on other types of cars forums, though - but after trying it out for a week I didn't personally notice any increase in hp or anything at all that helped really. So I keep it at zero and will solder it out eventually.
@@happyfox711 Exactly, if you're in the US with a working O2 sensor then the DME is going to see the mixture and correct the values anyway... so its a complete waste of time.
@@edredas I'm not in the States, but I do have an American 944, so I'll keep that in mind..
hi ...my car...the dash lights...'light up' when i turn the key......but No 'cranking-sounds' of the engine at All!! won't START...??...could this be the 'ignition switch'...or STARTER Problem? cheers
There's a plug behind the brake booster with a red wire. Disconnect it and have someone turn the key while you check the voltage there. If you have 12 volts on the red/black wire then the switch is working and it's likely the wiring or starter. If you don't have 12 volts with the key turned then its likely the switch. I hope that helps!
what is the metal TAB under the fan relay? should be #7 on the Relay column box on early 944 1:48 does that metal tab serve a purpose??
I believe it supplies a permanent connection between two connections.
Hello sir thank you for the explanation. I have a 1983 944 that been sitting in garage for 16 years. Now the engine cranks 2 times and nothing then 1 time and nothing. Any suggestions please?
Do you have tach bounce? That will tell you if power is being supplied to the DME and fuel pump, also give you an idea if you have spark. If the tach isn't bouncing then you need to swap out the DME relay first to make sure the DME is getting power. Otherwise nothing will happen even if the sensors are good. If there is bouncing verify that the fuel pump is turning on when the engine is turning over. Alternatively you can jump the relay. This will run the pump at all times. If the pump isn't working then you're not getting fuel. If the pump runs when jumped then see if the car will run on a small spritz of starting fluid. If it does then you have spark. Also you'll need to make sure that there aren't any vacuum leaks and the air flow meter is plugged in! Good luck!
edredas So I swap the dme , and replace sensors. Still no bounce. I even bought a ecu from eBay and still no bounce. Now when I do multimeter check Give me around 900 omhns and when cranking the engine I’m reading 0.02 volts at 20 V DC. Thinking is to low and need a gap adjustment?
Or may be the ECU and the one from eBay isn’t working as well?
And have no spark as well
hi man i have same problem here and i didnt find out yet the speed sensor and reference sensor is new and the tach not bounce when turning the engine over and the fuel pump working good and i get used ecu to try with car wont start the car is not starting for over 20 year it had 28000k only but today when i move the ecu and give it ground it start for 30 min and when i turn it off i cant started again i think the problem with my 2 ecu or some wiring can you help me pls solve this problem
Hi, if the tach is bouncing and the fuel pump is running every time you turn the engine over, it's more than likely a wiring issue. Do you have spark when it doesn't start?
@@edredas no spark and the tach is not
bouncing
Great video. How do you like that Legend car battery? Mine had a short life of one year.
Pretty good so far. I didn't buy it, though. It came with the car when I bought it three years ago. I think its currently about five years old, but I've never had an issue at all. I drive the car everyday and completed several long trips with no problems. I often use this car to jump my other cars off when their battery go flat from sitting...
edredas wow... Impressive
hey, my 84 944 isnt starting and it is for sure the immobilizer. (coil is grounding to alarm box, not DME). how do I fix this??
The Clarks Garage website has a diagram to jump the immobilizer that should help!
Hey edredas what would you do if you replaced the DME Relay + both sensors and still get no tach bounce or start?
I've actually narrowed it down to zero ground issue at pin 85 on the relay. When I manually add ground to the pin, tach bounce and car starts/runs perfect. Am I orrect in assuming the DME computer needs the input from the ref sensor to then send Earth back to the relay and complete fuel pump circuit/power to injectors?
I'm thinking I have wiring drama either from sensor plugs to DME or back to the relay board.
Will do these multi-meter tests tomorrow! Cheers
It's been a while but I believe that 85 is a constant ground. When the ignition switch on it sends power to 86, which switches the first relay on. This supplies power to the DME and injectors. Without a constant ground there on 85 I don't see how the relay would activate. Once the DME has power and sees a 200 rpm signal from the reference sensors, the DME will then send a ground back to 85b and turn the fuel pump on. So you're on the right track. That said, if you are not getting a constant ground at 85 then it is likely the grounds on the back of the engine and bell housing. There is a common issue where the grounds corrode overtime and you have all sorts of issues. Good luck!
Amazing mate, thanks for the reply. I’ll give them a clean today and hope that works! Legendary 🤞
My speed and reference sensor is stuck! Any tips or tricks for it to come out easier
Sometimes soaking them down with WD-40 and using a small set of long nose locking pliers will get them out. I hope that helps!
Have you tried the new solid state DME relay that's available now? They sound like the bee's knees when it comes to a quality replacement part for this troublesome item.
Not yet, I have a stack of brand new relays so I haven't had the need, but I am very tempted to get one! This car is daily driven and I also do a lot of road trips so it would be nice to just have one less thing to worry about. That said, in my almost 20 years of ownership and driving many of these cars daily, I have only experienced one DME relay failure. So, it isn't something I worry too much about. I had a spare with me so it wasn't a big deal. Now, if I buy a car I usually just go ahead and stick a new one in, so it has made this mostly a non-issue for me. This was only the second time I've ever had a no-start issue with a personal 944 series car, so if I were to get a soild-state relay it would just be to try it out. Thanks!
That's good to hear. When I get one of these cars together I'll expect it to by my daily driver as well, so it's nice to know they can be that reliable. I've accumulated most everything I need to make it happen, from a machined/plated ready to assemble block, to fully rebuilt transaxle, NOS AFM, Bosch factory reconditioned DME, and virtually everything in between. I just need a chassis to put it all in, and most importantly, time.
Hi, what should the BG read ??? My 87 924S starts and then stops in less then 30 yards could it be any of these sensors and I wish I could send you a pic because I have a 3rd wire next to those to that looks damaged? The car will start again after a few minutes and then stall again, I could probably drive cross country a hundred feeet at at time.
Both sensors should read 600-1600 ohms. There are three wires and if any are frayed it will cause and issue. However if it runs and dies it sounds more like a vacuum leak or fuel issue. I hope that helps!
@@edredas what is the third wire that runs behind the DG an BG?
Thank you very much! Does it mean that it didn't have a spark?
Yep, that sensor allows the DME to know the position of the crankshaft. So when it doesn't work there will be no spark or tach bounce!
edredas Thank you once more))
I believe when checking the sensors at the computer, it should be pins 25 and 26, not 26 and 27.
And also pins 8 and 27 should be the other sensor.
You are correct, I thought I would make this video in a hurry and did it by memory, which I shouldn't have.
Having a problem with my '83 944 where it will start, run for 30 secs or so and then stop. After it does that, It will start for maybe a second and then cut out....Knowing that the car does at least start, should I still look into replacing the relay and/or the reference sensor?
When a sensor or the DME relay fails the car will not start at all. Check that all the vacuum lines are connected. If the engine is running rough pull the vacuum line off the FPR and check to see if any fuel is dribbling out. That would mean that your FPR has failed. I hope that helps!
I have experienced on and off seize of engine while driving. I removed the DME relay, shook and placed back in and started. I replaced the DME relay at home and never had the problem again.
Hallo my puestion is dos the car dont start if ohne of this two Sensors is Bad.
Because my Car dont start but i find out That my speedsensor is Bad.
Car will not start if either of the two sensors are bad.
Would the DME keep the car from cranking?
Nope, with a bad DME the starter will still turn the engine over. If nothing is happening then it would either be a weak battery, bad starter, ignition switch, or wiring. I hope that helps!
Hey Ed. I just put my engine back together. No start but cranks but theres an odd screech noise after its fourth or 5th Cycle? I put the timing together as much as i can get it to but im concerned about that screech like if its metal? Got any ideas?
That doesn’t seem right… if you are on Facebook come join my group and upload a video.
I just joined the group. Actually the noise was pressure in the intake? I may have mixed vacuum lines or pressure lines that surrounds under the intake manifold. I get a shot of white blue smoke. After I pulled out the j boot a have fumes coming out.
Can the ignition switch cause similar problems? I need to get a new key and cylinder because I have to wiggle the key a bit to get it to turn, so I figured I might as well change that out as well since the switch is $5 at rockauto. I've replaced everything else but the wiring and the alarm. I get 890 ohms on each sensor at the DME harness plug, I have 12v at pins 18 and 35 on DME plug. Still no tach bounce, no spark. I have 12v at the coil with no change when turning over. I unplugged the alarm module and intalled the bypass jumpers into the harness plug, still nothing!
I believe so! I've never personally had an ignition switch break to know exactly what happens, but it is definitely in the realm of possibilities! Sounds the switch is an issue but I believe if you're getting 12 volts at the DME it might not be the issue. I'm not exactly sure what happens but I believe when the switch breaks the DME doesn't get power causing the no-start issue. That said, have you've tested the continuity at the pins for the sensors at the DME? They're known for fraying at the sensor and causing issues. If those are good I would suspect the dme is bad, I've had good luck repairing them before and its pretty straight forward. However, I would buy a $5 ignition switch first before buying a DME, since it sounds like it wouldn't hurt since its loose, but sounds like you're on the right track! Good luck!
@@edredas the sensors show 890 ohms at the DME plug, and I only get a couple milivolts DC when cranking over, I'm still trying to figure out the alarm bypass, do you unplug the module and replace it with jumpers, or jumper the plug while connected to the alarm module? I've got new sensors, new DME relay AND a remanufactuered DME. The wires on the plugs for sensors on harness look good as the sensors ohm out OK at the DME plug.
I bought this car not running and have rebuilt the motor do to bent intake valves from a misaligned timing belt when the previous owner tried to replace the belt. I've been working on this car for 2 years and really want to fire it up and drive it for the first time... so frustrating. ..
@@edredas so... I've replaced everything now, dme relay, remanufactured dme, reference sensors, ignition switch, alarm bypass proceedure... still no tach bounce... i bought the cheaper reference sensors, wondering if that was a mistake? Have you used or had problems with Facet or FAE brands of sensors? Should i drop another $140 to get the Bosch sensors? You are my last hope OBIWAN EDREDAS!
@@edwardkipp4911 I've used the cheaper sensors many times without an issues, so that shouldn't be the problem. At this point it is very hard to say what the issue could be. Have you checked that the sensor are gaped correctly? Sounds like it you've covered everything an on the right track...
On the back of the DMG plug, you test resistance between pins 26 and 27? I thought (?) for the reference sensor it is pins 25 and 26?
Yeah that’s correct. I goofed. I was doing this off the top of my head and just threw this video together in 5 minutes. I was just trying give an idea of things to check but as always everyone should check the manual and follow those steps.
Your videos have been SO helpful to me as I tackle this field-find 83 944. I just don't know what I'm doing, which means I have to double (triple?) check everything to make sure I'm following directions.
Because (duh) no spark. So just double checking.
Again, though, THANK YOU for this and all your videos!
Your vacuum video saved my rear end: someone had pulled many of my lines and reconnected some in the wrong places, and without your video, I never would have sorted out the diagrams. Did I say thank you? :)
Awesome, glad I could help!
How can you test the wiring harness?
Remove the plug from the DME and unplug the sensors. Then use a multimeter to make sure there is continuity from the pins in the plug to the appropriate DME pin. If you don’t get a reading then the wire is broken. I hope that helps!
Hey man i have a 944 with no spark and it has new reference and speed sensors, new plugs and wires, new coil and cap/rotor, new fuel pump and ignition coil and i still cant figure out whats wrong. I replaced multi function and dme relays and the dme computer has power
Also has a new battery and i have tested 12v to the coil. Only thing i can imagine is an ignition switch or harness failure. Any suggestions?????
Sounds like you’ve covered everything however it could be the DME itself at this point. There are places such as ecu doctors that will repair them. However the most common cause is broken solder joints at the spark controller inside. So if your handy with a solder iron then Ive help a lot of people repair their no spark issue with a 99% success rate.
Is the top sensor always the speed sensor? Both of mine were disconnected from the top bracket and didnt have the label on the harness side.
DSimmons1265 not always since they are easily be swapped around. If they’re mixed up then it won’t hurt anything and you can just swap them back and the car should run.
Ah, thanks. You have no idea how much your videos have helped.
Hi we have a 944 one built in 85, at the moment with the problem that when the car is cold it accelerates and drives normally, but as soon as it gets warm it starts to stutter and jerk when accelerating. The problem occurred when I brought the car out of hibernation after it had been sitting for about 5 months. Before that, the car ran perfectly and didn't twitch at all. We have replaced the intank fuel filter as well as the filter after the pump as our first suspicion was dirt in the fuel but that was not the problem. Is it possible that the mass air flow sensor is suddenly broken due to standing still or what could be the reason? We need help or tips for diagnosis. Kind regards Jonas
I’ve seen something similar before. Does the car happen to have a hole in the battery tray? Sometimes water will drip down onto the computer and ruin it. The symptoms won’t show up until the computer gets warm and starts malfunctioning.
@@edredas thanks I have checked that just now and there is no hole plus the car was stores inside and hasn't Seen water in a long time…. Any other possible causes ideas?
I got the other DME in the mail and plugged it in, still no change, no tach bounce, no spark at coil... what is between the dme and the coil? Is the factory alarm in there somewhere? Is there a relay that connects dme to coil? How far are you from Lockport, NY?
Hi, I'm just outside Charlotte, NC so quite a drive. Sorry to hear you're still having issues. The alarm very well could be an issue but there are some ways you can jump it, if your car is equipped. Here's a pelican write up that might help!
www.pelicanparts.com/techarticles/Porsche_944_Turbo/36-ELEC-Troubleshooting_the_Alarm_System/36-ELEC-Troubleshooting_the_Alarm_System.htm
edredas , yeah, that's a little bit too far to have you stop by and check it out, lol, I'll try bypass g the alarm next, hopefully that gets me started... thanks again for your help, I really appreciate it... Edward
So... I'm a little confused about bypassing the alarm system, do you unplug the connectors and replace with the jumpers, or add the jumpers while connectors are plugged into alarm module?... I'm at my wits end, I've replaced both sensors, the dme relay, and got a remanufactured dme... the alarm is all that's left as far as I know...
When I rotate my key to the mission setting all I hear is a clicking sound coming from the fuse Box would you have any idea what this could be?
The DME relay will click when you turn the switch. Check the voltage on the small wire at the starter so make sure you're getting 12 volts there when the switch is turned. If you have 12 volts then the starter is bad, but if you have the correct voltage try replacing the DME relay. I hope that helps!
@@edredas OK put it brainy relay I put in the 2 centuries to the crank. I got it to do exactly what your videos doing in the beginning, But still no Ignition I Tried some Ignition spray. I got it to turn over for 2nd turned off I looked at the starter it's severely corroded. I tried to screw driver test got export they turned over the starter. But now the car won't do anything.
If you're jumping the starter with a screwdriver and its not working then it sounds like it could be the starter...
@@edredas I just replace the starter. It sounds like it want to turn over a lot more stronger. But still Not running.
Do you see the tach bouncing when cranking the engine? That should mean you have spark. If you have spark try using a jumper on the DME relay and see if the fuel pump runs. If you have spark and the fuel pump is running check the injector pulse with a noid light. That should get you started. If all those things are good then you might be worth checking to see if the timing belt has broken.
Will a bad ecu cause a no tach bounce?
I have a 1984 Porsche 944 that I was driving to my home one day it stalled so I swapped in a spare dme relay that got me home when I tried starting it to go to work the car wouldn't start and at this point I had no tachometer bounce so I changed my reference sensors and then the tach bunched but car not start unless I ran a switch to the pump on a fused relayed switch it started but only with bypass the dme relay completely. The car started with the switched power to fuel pump but it does hot stalls when it heats to normal temps it stalls. Yesterday I unplugged my ecu and plugged it back in and now my tachometer wont bounce I unplugged it and plugged it back in again and nothing no start no tach bounce now and I just want to drive my car again but my project has been sitting because it is so damn confusing.
Sounds like it could be a wiring issue. I've seen the wires on the back of the relay board come out and make it where the DME can no longer control the relay. That said, if you unplugged the DME and its not working, it could be bent pins in the connector or all this could mean the DME itself is bad. I would check all the wiring first and if everything looks good it could have been the DME the entire time. I hope that helps!
@@edredas well that is a very good possibility with the wires. I mean that's a mess my cousin ruined this poor car. He had the fuel pump ran off speaker wire running past the dme relay that's the only way he could get it to run but then I dont know if it is trying to give power while it was bypassed on a different relay and switch it runs then will stall. If it was giving power to the original wires that where capped and the new wires ran so I could get the car home. Did that short anything in the car maybe? Is the dme just shutting fuel off because maybe there is a short on a wire that goes to the dme relay for the fuel pump is there anywhere that has a wiring diagram that shows how to rewire the dme relay socket that the relay plugs into or does Somewhere sell a pigtail or a harness that plugs to dme relay then something that gets constant power , something that has accessory power , the dme itself , fuel system and a ground wire? Is there a place that shows this anywhere that you know of. Also what is the actual part number or relay that is supposed to be my ignition relay it works I believe but my 1984 Porsche 944 has a 928 ignition relay and all 4 corners are folded out from the circuit board. I do have some new reference sensors coming in even though I changed those a few months ago but the car has been sitting when I did change them the tachometer was working but now again its not.
Well I have all wires connected to the relay I used the two different dme relays and two different dme relays I've swapped out the reference sensors for spare ones the sensors get power but wont make my tachometer bounce still the sensors get power from my dme but wont work but the same sensors where at the same gap and they worked until last week =/ do you know of anything else that would do this please anything helps I mean I wish you lived close to me I'd pay you to fix it but your far away lol
Would you hear the fuelpump in this? I dont have any tach bounce. But when I use the multimeter i get some form of reading. 174 on 2k ohm. Not sure if I measure right place. Should the notch be the raised "bump" or like a notch inwards, and this facing up measure left and middle?
The fuel pump will only run if the computer sees that the engine is running. So without tach bounce the computer isn’t recognizing that the engine is spinning. So there is likely an issue with the sensors if you have no ohm reading at all with the engine off. I believe the bump should be on top but with the lead on the center terminal you can try each one. At least one should have a reading but if not then they are toast. I hope that helps!
@@edredas thanks alot!
@@edredas standing in front of the car, is the reference sensor the one closest to the windshield or closest to the front of car ? Thanks.
@@kajalver5743 the reference sensor is the one closest to the block/front of the car.
@@edredas last question haha. I replaced both sensors, still no go. Will tach not bounce if sensors are good but relay is bad?
Simple question.I'm going to help a friend get his No Start 1987 Turbo 944 running.He thought it was a coil issue and now it has sat 7 yrs,,Lack of knowledge and raising a young family..The weekend autocross car gets forgotten..QUESTION Are the Sensors the same??When buying a Crankshaft /TDC sensor it can also be the Speed sensor?.Having a hard time finding both.Haven't worked in 944 yet. Thankyou..I'll be checking belts and replacing fluids ETC
Yep, both sensors are the same! Another thing that can cause I no-start that I didn't cover in this video is the fuel pump itself. However I showed how to troubleshoot that in my 'Nautic blue 944 turbo' series. I hope that helps!
@@edredas Thanks for quick replay.Did see your 944 turbo video..Saw you removing 2 boxes of Sensors.. Just saw Pelican lists 2 needed per car. Didn't notice that before. My Friend with the 944 needs to watch all your videos..I'll demand it of him..:) great videos!
.I'm fearing the oil separator on the Turbo cars is going to make it more difficult to get these sensors out..Working on it tomorrow.. Also I see you got the FACET sensor . Plastic wraped instead of bare metal.. .Do those corrode less and not bind as much..?Thanks Again
I think the binding comes from the rubber o-ring hardening over time. So any brand will likely get stuck over the course of 30 years. I’ve heard that some people use anti-seize on them to prevent that. Before removing I always soak them down with wd-40 and wait a while. I hope that helps!
Do you get your reference sensor from pelican parts? And if so what brand do you suggest?
Yup, I got them from Pelican. I usually just go with whatever is the cheapest one that week. I've never had any issues with any of them. Every sensor I've ever replaced was nearly 30 years old so I figure that even if the cheap ones last 20 years you've gotten your money's worth. Good luck!
@@edredas thank you for the quick response. I was leaving for work today and go a no start on my 85.5 944. Haven’t been able to check for tac bounce yet but was searching parts just in case. All your videos have helped me as a new 944 owner. Thank you