Porsche Enthusiasts Club Forum

Hi all, well since i got my lux on the road a few weeks back i have been lucky enough to enjoy 170 miles of uninterrupted motoring before i have hit a problem.
Last week i took the car out, ran fine but when i stopped to put the car in the garage it wouldnt start again. Done all the usual checks, swapped the DME for a spare but still wouldnt start.
Thought it might be the reference/crank sensor so gave them a bit of a clean and it fired up fine. All was ok for a week but the same thing happened again when i stopped for petrol yesterday except this time no amount of cleaning them would get it going. There is no bounce at the tach but the car will start from a bump start and then runs fine.
Does this sound like the reference sensor needs replacing and is it just a case of buying a new one and replacing it or does it need a gap setting?
I bow to your greater knowledge as im not really clued up on the sensors and my knowledge is limited.
cheers
shaun

Or alternatively is there anyone in Brum that has a spare ref sensor i could borrow to see if that is indeed the problem please. Dont wanna shell out for something incase its not the problem.
Thanks
shaun

I'd have thought it might be sensors but why does it go on a bump?

The sensors can break on removal so I'd be careful about trying to trial fit some.

My suspicion would be the AFM (Air Flow Meter) or TPS (Throttle Position Switch) if you have a look at the pelican website (stickied here) then that shows a way of checking them. They can both be checked with a meter, if it is the AFM then it may be sticky.

Cheers Jim will check the pelican site.
I had to get the AA out yesterday and the guy also thought it was the ref sensor which backed up my first thought.
Would it not go with a bump if it was the ref sensor? I thought the ref sensor was only part of the initial starting process or am i barking up the wrong tree?
Shaun

No it wouldn't unless the sensor has a low output which by bumping it increases just enough? When you bump it does the rev counter bounce all the time whn you bump start it?

To be honest i didnt watch the tach when i bumped it so its something i would have to check.
As i said once its bumped it starts and runs and drives just fine. Its once i try and restart it that the problems begin.