[Tuttobenne]

A friend's 930 recently has been giving him trouble. On a recent drive his car simply shut off and wouldn't restart for another 20 minutes. We were on a busy road and I know little about Porsches so I couldn't really help other than to stand by until it finally restarted and I followed him home.

I hadn't realized he has been struggling with this problem for a while; he felt he had fuel pump problems, so I offered to help. Here is what I have found so far:

1. When cold, the car fired up and ran fine in his garage for around 30 minutes of idling. It simply shut off on its own though and would not restart. After fiddling around for quite some time I came away with more questions than answers so I did some reading online.

2. Returned to the car. Disconnected the connector on the front of the airflow meter. Turned on the ignition (did not crank the motor) and the both pumps ran fine.

3. Turned the ignition off and reconnected the connector on the airflow meter. Depressed the plate slightly with the ignition on and once again, the pumps ran. Started the car and let it run for a half hour before the pizza arrived. Shut it off and tried to restart and it fired up fine.

4. After lunch went back to start it and it just cranked. Took the connector off again and the pumps both came on fine.

5. Pulled the coil wire at the coil and held it close enough to the tower that a spark should jump. My buddy turned the key on and as soon as he did, a spark jumped across the gap into the coil tower. But once he started cranking, no spark.

I can understand the pumps not running until the airflow plate moves sufficiently but why no spark? Is there some logic in the circuit that inhibits ignition under certain conditions? What should I check?

I was thinking Crankshaft position sensor but then I read the distributor is relatively simple with a magnetic pickup triggering the Ignition Module. He has a partial Workshop Manual which stops in the middle of section 28, which is Ignition. There are some tests I can do and next time at the car I will do them. But I don't think I have enough information to rule the module in or out because the manual stops in the midst of checking it. Any thoughts?

Of course, if anyone has a better track for me to chase down, I am good with that too. Gotta say that its nice working with an engine that is all right there pretty much in front of you. And the heat is appreciated too. Thanks in advance.