I am new to this site, and am hoping someone can give me some insight into a peculiar problem that began on Christmas. I was on a road trip on Christmas and stopped to get gas after about 3 hours of driving. Got back in the car after about 5 minutes and the car would not restart. Tried for about an hour but to no avail. Car would crank, had all accessories, but it just would not turn over. Started up the next morning, so we drove home. Got gas 2 more times no problems. Third time I got gas same problem, car would not start. This time the car was cold. Had it towed to the dealer, where the car started. Let them keep it for 4 days, but they could not get it to foul again. So they put a new fuel relay in, but were unclear as to whether this was the problem. Basically, they told me they had no idea what's wrong. Any ideas? Thanks for the help.
Matt

 

Your statement: Car would crank but not turn over!! What do you mean? Is it a tiptronic or standard?

 

Standard. The car sounds like it's trying to start but just won't turn over. Makes all the right sounds, fuel pump primes, and it cranks, but won't catch and start.

 

Cranking and turning over are the same. You mean the engine wont start. Saying the motor will not turn over is saying the engine is eitther locked up or on the starter side, there is a problem.

Do you smell fuel coming from the exhaust? If you do, the coolant temp sensor might be out.

The fact you are only having the issue once you crack the gas cap might be related to emissions or fuel pressure bleeding off.

 

I had a similar problem. Car would not start after parking at the mall. Just cranked but never fired. Called the service manager who told me to let it sit for 20 minutes. He thought it might be the fuel. After 20 minutes it did start. Started to drive it home and then it died again at a light. Had to be towed to the dealership.

Turned out that the crankshaft speed sensor was failing intermittently. That is the sensor that cuts the engine off when you overrev. Once they replaced that all was ok. This happened just after the transmission had been replace so it kind of narrowed it down where to look.

In your case though, it could be a lot of places. It failing after getting gas could just be a coincidence. These kinds of problems are the hardest to figure out.

The fuel pump in my 1970 911 used to get stuck ever once in a while. I remember having to crawl under the car and tap it to get it unstuck. The same car used to get vapor locks on hot days and I would have to push it into the shade and wait to start it. And you had to pull levers to start it or you would blow the airbox out. You new guys don't know how good you have it with the newer Porsches. The old ones were fun to drive, but they had their share of little idocyncracies.

 

There was a very recent thread with another C2 that had starting problems. Basically, the car starts good when it's cold, but if you drive for while then stop, restarts are hard. If these are your symptoms, t is most likely the starter. [It sounds like these are your symptoms since the dealer would only have cold starts and could never repeat the problem (i.e., the won't drive your car to get it hot then stop and restart)]

A search should pull up that thread, where lots of advice was given.

-td

 

Thanks for all the insight. It only happens after gettting gas, and I am due to have to fill up this weekend, hope it doesn't leave me stranded. At least I have some ideas to tell the dealer the next time it happens. Is that bad that we have to tell the dealer what to look for?

 

Help the dealer with any info you can provide so they can troubleshoot your start problem.

 

Any problem that comes and goes can be very difficult to diagnose. A good example was how my transmission got replaced. I first had them look for a whining noise I heard last spring. Before they figured out that it was the limited slip clutches inside the transmission they replaced a whole bunch of other things. I didn't complain as I got a lot of freebies under the warranty. Luckily my car was not stalling or anything. I just had an annoying noise. Replacing the transmission finally fixed it.

Just hope you have a service manager who will keep on it.