[Santos]

I have a non-turbo '83 944 Porsche that turns ON but dies immediately. I had some good mechanics look at the car and now I have it at an electrical shop. I would really appreciate input and suggestions from this forum.

Here is what happens:

1. I turn the key and the car turns ON while the Starter is engaged, but as soon as I have the key move to the ON position the car dies immediately. If I keep the key in position such that the Starter is engaged, the engine stays ON and as expected extra noisy. I thought the issue could be the ignition electrical switch and I installed a new one but the issue was not resolved.

2. If I disconnect the air hose at the throttle body input and I pour in starter fluid (I used gasoline from my gas tank to check the fuel quality), the car stays ON without having the Starter engaged continously. I can move the key to the ON position and accelerate the car to a few thousand RPMS (~4000, maybe a little more) as long as I have starter fluid or gasoline flowing into the throttle body input. This tells me that the spark plugs and distributor are doing their job. And, I suspect that the fuel injectors are shutting down completely or getting a weak signal to the fuel injectors when I move the key to the ON position.

3. I took the car to an electric shop. And the technician told me that the fuel injectors were getting a weak electrical signal (barely spraying any fuel). The technician manually grounded the injectors and we were able to maintain the engine running smoothly while the key was in the ON position. So, we know that the issue of the engining dying is due to lack of fuel. Fuel pressure is good. Fuel injectors are opening and firing nice amount of fuel when technian manually turned the fuel injectors ON. Why do the fuel injectors get enough power to turn ON the engine when I have the starter engaged, but then signal is too weak when keys are turned to ON position? Does the fuel pump turn ON at some specific engine RPM?

4. When we disconnect the DME temperature sensor, we were able to turn ON the car and keep the engine running while the key was in the ON position. The engine was difficult to turn ON with the DME temperature sensor disconnected and we are NOT able to accelerate the engine smoothly. If I depress the accelerator quickly, the engine will die out. So, we thought we needed a new DME temperature sensor. I installed a new DME temperature sensor and I still have the same problem. I turn ON the engine with starter engaged and the engine dies out immediately when I turn the key to ON position.

The technician thinks the Mass Air flow sensor might be the issue. But, I am not convinced and I want to avoid spending money on items that will not fix the issue. At first, the technician thought that the mass air flow sensor was good based on voltages he checked. The voltage output on the mass air flow sensor increases as the flap angle opens toward the OPEN position. I recently gave the technician a printout of an article on Clarck's Garage which has details on checking the 944 mass air flow sensor. I hope he can pinpoint the issue with the mass air flow sensor.

Per the technician, all the ground signals from the DME control unit look good. He also checked the fuse BOX and relay BOX and said that all voltages and grounds look good.

Could the issue be related to the TPS sensor? Could the temperature sensor inside the mass air flow sensor cause the issue I am seeing?

Obviously, the fuel injectors are getting a strong enough signal to turn ON the engine when I have the starter engaged. But, then the signal is too weak to feed enough fuel to the engine when I put the key to the ON position.

Any suggestions from the Forum appreciated. I'll check or have the techie check stuff that this forum suggests.

Thanks in advance,
Santos