Roy Rabold

I have a 1986 944 that has an electrical problem. When it is cold, it runs fine for about 10 minutes, than it shuts off and won't run. I have replaced the following: cap, rotor, spark plug wires, coil, throttle switch, speed and reference sensors, water temperature sensor, fuel pump relay, sensor to temperature gauge, temperature sensor to the fuel injectors. I had the same problem 6 months ago and replace everything but the sensor to the temperature gauge and it ran. Three months ago I replaced the temperature sensor to the injectors and it ran. Now it has stopped again. Any ideas

V2Rocket

have you tried a different DME?

Roy Rabold

I replaced the DME

V2Rocket

Does it stutter/stumble and die or just shut off completely all at once?

Roy Rabold

It shuts off all at once

GPA951s

Although many "quirks" might be common across the same model, you have an issue that unique. Having said that, you really need to diagnose the problem. It seems like some parts were shotgunned. start with the simple stuff, Fuel or spark? when it dies which one is it? Fuel pump could be getting tired? if its new that doesn't mean its good. There is good access to the fuel rail on these cars. some guys even run a permanent gauge. makes it e-z to troubleshoot. The wiring harness on these cars is very old... Check the injector harness, all the injectors share the same two wires. as the heat gets to these the insulation cracks and fatigue can open or worse short these wires, and when they contact each other...shutdown.. I would lean towards the fuel system but if you eliminate the entire system the move on to ignition... Tach bounce when cranking? when the crank sensors were put in, was the gap checked? did it have crap on it? I have heard that some of the NA's have that isolation rubber in the clutch and that comes apart and gets in the flywheel and eventually screws sensors up...

V2Rocket

see if you can reach under the dash and pull the plug off the back of the ignition switch, and bridge the terminals (hot wire the car basically) and see if the car runs normal or if it still dies.

944 ignition switches are a known failure point...

Jfrahm

When it won't start, have you tried replacing the DME relay with the jumper wire as per Clark's Garage?

Did you actually try a different DME or just the DME relay (fuel pump relay)?

JimV8

Here's one that happened to my 944. It quit suddenly and I found it was the plug connector at the top back of the engine. i'd replaced the clutch and the sensors but I guess i messed up getting a good connection at the connection.