Thank You for this view and description. Please post the link or site address for the schematics mentioned. Today, the supply of DMEes is becoming rare so I hope to repair the one from the car if possible. Thank you for all your videos!!!
hello, I have a Porsche 944 with a problem of irregularity and maintaining the idle in hot conditions. The previous owner replaced the bosch motronic ECU with a recovery one and the car is now fine. I opened the ECU and was looking for the damage. Apart from some oxide, visually no damage is visible. From your video I understood that the affected card is the analog one. Could you tell me the IC that commands the minimum or maybe the part where I could find the defect? Thanks from Italy.
Hey I have a 1986 Porsche 944 and my fuel pump isn’t working a week after I replaced it. I checked the fuse and the dme relay, could replacing the dme fix that and is there any way to test that?
Hey, been watching your channel for a long time now. I'm now considering buying a 944 but wonder what years of the DME go bad? Also anyway you can make a video of what to look for/inspect when buying a 944? Thanks man. Gonna look for a good chip too
Do u have spark? Remove a spark plug and see if it is firing then try another one. If neither fire replace the distributor and rotary cap. If the fire, go back to fuel. Try removing the bolt on the return of the fuel rail and see if gas comes out while starting. Remember to hold a jar to catch the fuel. No fuel means DME possibly. Fuel means injectors. Hope that helps!
I found cold solder joints on the DME so I eventually replaced it. There was a hole in the battery tray that leaked water down the glove box, down the passenger foot well where the dme was.
hello, i am Hendrik from Belgium. I own a 1985 911 since 4 years. Up till now it ran very well. 2 weeks ago i got problems: cold engine is still ok, idle is fine and it runs fine when cold. But when it is becoming warmer (5 km or so) the engine starts to hesitate, it doesn't pull like normal, idle is rough. Above 4.000 rpm it is OK. I started with a check-list: plugs, plug wires, distributor, rotor, fuel filter, NTC, DME-relais and last the air flow meter. Result: the car is still running bad. I now think that the DME is the issue. Is there any way to measure the different components? Thanks!
ducsoef hey there, if you have no problems above 4k when the car is warm, i wouldnt suspect a fuel pressure problem. So that rules out fuel clogging in the tank, fuel pressure regulator failure. But what it does say is the car may not be getting the proper amount of air at low rpms when warm. When cold, there is extra gas in the ratio, just like when your above for 4k. but warm the ratio is reduced at idle. If this was a fuel problem, the car wouldn't run at all above 4k, it would bog down. I think a good throttle body adjustment may help you rather than a DME replacement. I haven't seen the DME affect the car in this particularly way. There's an idle stabilizer that controls the idle when the car is warm or cold. i would try disabling the idle stabilizer by jumping the ports in the diagnostic plug and adjusting the throttle place while the car is warm. My newest video has the simple instructions.
hello, thanks for your solid explanation. Next step will be checking the throttle switch (with the 3 pins - can you explain how to do this?) and looking for vacuüm leaks. Meanwhile i opened the DME-box. It looked brand-new and i couldn't find any visual error. I keep you informed!
Hey buddy, my 85.5 has a fuel issue which sounds similar to yours, i have no injection pulse to the injectors verified by a noid light. Both my speed and reference sensors are new and the circuits have been tested to the dme itself and tests good. Had my dme resoldered but that didnt solve anything, have power but no ground pulse to injectors. I have tried everything from new sensors to cleaning all the grounds, any idea of where this could lead? Im thinking the DME itself could have a bad injector driver but not 100% confident in that.
My 1984 Porsche 944 na has idle bounce a lot at random times especially while slowing down going about 30-40 would you know anything about that? Could that be the DME/ECU? Or maybe o2 sensors? I don't know please let me know:)
So when you're slowing down does it seem like your tach drops completely or is operates but inconsistently? A bad o2 sensor may read to rich and cause the DME to lean out your mixture and cause the engine to stubble.
Yay Area Garage I'd check the distributor, rotor, and spark plug wires. if they are all good, then it may be the DME. Visually check your reference sensors also. If you narrow it down to the DME, I'd look over everything involved in the ignition side. Something may be causing you to loose spark. I don't think it's fuel because the you don't experience degradation of performance slow, which is consistent with fuel starvation.
