altownsend

Porsche 1988 944 Base Model

I have read all of the threads that I could find about this, and found that I need to write one on my problem.

Two times, my 944 base model engine just stopped. Once while sitting at idle and the other while driving.

Gauges worked, and it started right up when I turned the key.

Now, the engine temporarily cuts off but does not shut down. I notice the RPM drop while other gauges remain operational.

Does anyone know what the problem might be?

I read about the following:

Fuel pump
Fuel Relay
Fuel filter
Speed sensor
DME
Ignition control module

Does anyone have a fix? Thanks

Dan Martinic

You'll probably want to start testing the parts you list above, starting with the DME Relay. That one's pretty easy. Here's a good guide: https://www.pelicanparts.com/techart...leshooting.htm

If the engine doesn't stall our cut out with the jumper installed, order a new relay or fix your old one. While testing, if driving around be sure to remove the jumper when you shut off the motor; otherwise, the fuel pump will constantly run.

If you still have problems with the jumper installed, you could watch your fuel pressure. This is difficult as the connection is at the front of the engine and isn't standard.

I would skip to reference sensors, wiggling the connectors. It's very common for the wires inside the connectors to be a problem. If wiggling around the sensor wires doesn't cause any problems, you can test the output of the sensors themselves. This is best done with an oscilloscope, but you can kinda get a feel for operation from a regular voltmeter. Try this:
If that seems fine, I would remove the ECU (under the passenger's feet), open it up, and look for little tiny cracks in the solder like this:




Use a soldering iron to heat up the joint and flow some fresh solder on it. I fixed these cracks and that solved my weird stalling / cut out problem.

altownsend

1988 944 Base Model

I replaced the fuel filter and DME Relay. Now, the car has, twice, gone into limp mode. For those who have owned the X-Type Jaguar, you know what I am talking about. When the engine shuts down, it does not completely turn off. The engine goes into limp mode. No gauge lights come on, power steering is maintained, no dash lights, no sputtering or change in performance, besides the fact that the engine looses power and reduces RPM to about 1100 RPM. The limp mode condition lasts for about 10 seconds, and then, the engine power picks back up and I continue on my way.

Any ideas?