3.6 Stalls out only when driving
 

'74 911 with '95 993 3.6

The mechanic is stumped on this one. The car runs great sitting still, starts, runs, idles, revs - everything seems normal. However if you throw the car in gear and drive you won't get 20 feet before the car sounds bogged down and then stalls out, the car then becomes hard to start - but given time will start again. My mechanic suspected the TPS, but after replacing it the problem remained. He seems confident that I have some sort of fuel delivery problem, but not of where the problem originates.

He's prob. right. When the fuel pump gets hot, it quits working or loses pressure. Leave the car sit for a few minutes and when the pump cools down, it work until it gets hot and the pressure falls.

Had a few non Porcshe cars w/ the same symptoms.

Clogging of the fuel system? The fuel needed to idle and reve in standstill is much less than when driving. The "curing" effect you see, really speaks for your mechanic's guess of a fuel problem (clogging).

George

the fuel pump would not get that hot in that short of time, cavitation (spelling?) would happen after the temps were very hot. I would think it's something different. Maybe Ingo or Bill would have a better answer for you...possibly DME related (Fault codes).

All fixed up - turned out to be the reference sensor - running beautifully now!!!