thecosmiccodex

Hello all, I'm new to the forums so let me know if I've got anything wrong already. I just purchased my first Porsche, an 83 944 n/a. After about a week of ownership it stopped running as I was driving home. It started running rough so I pulled over and turnned it off. I haven't been able to start it since. The DME relay has been an issue the whole time I owned it. Had to wiggle it to start sometimes. I had it towed to a shop the diagnosed it with a bad DME but I'm unsure due to the relay difficulty. Is there a test I can do to confirm their diagnosis? Or possibly, someone in the Asheville nc area that would be willing to let me plug my computer into their 944. Thank you all for any advice.
Happy wrenching!

plumbum

I am not going to be a whole lot of help but my DME relay went after a few weeks of intermittent long cranks. The relay was stamped 1991 on it (my car is a 89) either way its a good thing to change and have a spare...pick one up and try it and worse case you may need it later.

thecosmiccodex

Thanks for the suggestion, I might pick up a new one. I found 2 in the car and tried them. I think if its not the DME its the socket for the relay or, dun dun dun, the loom

adrian_jaye

it'll be the fuse box (forgotton what there called now officially) that the DME, fits into,

ITS A PAIN to try and fix it, you may get lucky and tighten the spade connectors, its like a 1000 pcs jigsaw, if you open it, you'll be SOL

replace it, and dont get one from a breakers/spares yard

I think about 5 years ago I rplaced mine, it was around £150 for the part,
and actually, replacing the part is a pain but can be done carfully,

but DO NOT pull the fuse box apart.... DONT

thecosmiccodex

Do you mean the relay panel under the dash?

Jbsmith

Just my 2 cents, ill search hard for a link which ill post once i find it, but there are tests. However, im no electrician and i cant remember off the top of my head what the test is actually for.. But your dme relay is somehow related to your fuel pump, when you turn the key you should hear your fuel pump turn on.. But anyway, the test either checks that your relay is ok, your dme is ok, or your fuel pump is ok. I cant remember, but anyway it involves using a paper clip, which youll wrap around 3 of the prongs on your relay. I think what is happening when you plug the relay back in, the dme is being bypassed and your fuel pump is turning on

thecosmiccodex

I have tried jumpering the relay. The fuel pump kicked on but it would still not start

plumbum

Did you check the plugs after to see if they were soaked in fuel? If not it could be the injectors not opening and if they were could be a spark or plug issue?

aj986s

I believe the DME controls the fuel pump, as part of its operation. You may want to check the fuel pump, and filter too. If car was sitting a loooong time, there's a possibility of crud in the gas tank.

Also confirm connection and operation of the crank position sensor, located at the back of the engine near the firewall. I had an intermittent connection problem on an 85.5 944 I used to own.

Good luck sorting it out. The 83's are old school, but many had manual steering rack and LSD's. An issue to keep in mind is the hollow spindle used on the left front to facilitate the speedo sensor. Its a potential weak link if the car is tracked or autocrossed.

thecosmiccodex

Ended up being the crank and reference sensors and some loose wiring behind the relay panel, thanks everyone