porsche 944 engine problems

[motorsportpd]

Hello everyone. I am new to this forum and have an issue requiring help I have a 1983 Porsche 944. It has developed a fault where the car will start fine and sound sweet but only run for 3 seconds and then cut out/ die. If during this time you touch the accelerator then it will keep running but will pop spit and bang while the engine over fuels. The revs also want to go up on their own during this time and take a while before they die off. If you take your foot off the accelerator then it will just die. I have replaced the following.

-Fuel injectors have been overhauled.
-Inlet manifold gaskets replaced with the hoses underneath and there are no inlet leaks.
-DME relay has been replaced along with the air flow flap meter.
-Plugs have all been out and gapped and cleaned.
-The coil has been checked and ok.
-Reference and speed sensors have all belled out and appear ok.
-my model does not have an o2 sensor in the exhaust
-fuel pressure is good hence the rich running.
-DME brain removed and checked with no signs of water ingress burns or broken tracks.

This car has been standing around a while now because of this fault and i am starting to loose the will to live!!!!!

Any thoughts / Help? I really dont want to continue to throw money at this car with no gain hence why I havent changed the ECU. Is there anyone in the Leighton Buzzard / Milton keynes area of the UK who can allow me to plug in their square dash ECU into my car and see if it bursts into life.

Cheers

[Ky914Newbie]

I had a problem with a fuel pressure regulator that caused my car to run very rich and die. Here is a test from Clarks-Garage.

"If you have a condition where the car will not start or starts and almost immediately dies, try disconnecting the wire for one (1) injector. Attempt to start the engine. If it starts and continues to run, the fuel pressure regulator is likely bad. Bear in mind that running on only three cylinders, the car will run very rough. By disconnecting one injector, it reduces the current enough to keep the injector drivers from shutting down."

Fuel Pressure Regulator - General Information and Replacement

[fmartinez1897]

Check your Vacuum lines. I had the exact same issue, and it turned out a vacuum line was disconnected.

[mytrplseven]

Info on vacuum system test: I recommend getting a 2" PVC cap from Home Depot and drill and thread in an air nipple. Push this into the inlet of the J boot and clamp it. Apply no more than 10 psi of air from a compressor and then spray the entire engine with soapy water solution. Bubbles will show where all vacuum leaks are. Also look under the intake manifold and under the J boot. There's a T fitting under there that goes to the ISV. Also spray the ISV and the temp sensor behind it (under the intake manifold). Also spray the Throttle Body. I had a lot of bubbles from the shaft area where the springs go around it. There's little rubber seals in there that get hard and let the vacuum leak. A kit is available for about $20. Get a copy of the vacuum system from Clark's Garage to see where all the possible fittings are.