Engine quits for no apparent reason

[Kim]

Just in case this may help someone else:

 

My car (2000, 996, cab with 165,000 miles) quit cold on 3 separate occasions recently. First on interstate at 60 mph; second in stop/go traffic; third while idling in a parking lot. On each occasion, attempts to re-start were useless. Starter turned, motor cranked over, but no firing.

 

After each wrecker ordeal, it always started just fine several hours later. I was clueless. I even had the (original)  fuel pump and associated relays replaced on spec. I had to find the cause as I had to be able to trust my car to get to work at all times of the day and night.

 

After third episode, I took it to a local shop (Gold Crest in Kennesaw, GA) They discovered the crank position sensor wire had a hidden break (inside the intact insulation) that would change position and lose continuity when sufficiently heated. Without the signal from this wire, the engine simply would not run. Later, after the car sat for a while, the wire would regain contact, and the engine would start as if nothing ever happened.

[judgejon]

Did you ever run a Durametric or piwis test?  What was the code found by your inde shop?

Glad this worked out ok for you.  Fuel pump change over will likely pay off in the long run.

[Kim]

Yes. The car was checked for codes. They revealed upcoming issues such as, "your right cat converter will not pass its next emissions check" ... but nothing related to the stalling and subsequent restart after cooling. This shop happened to have a tech who was familiar with the crank position signal issue. I agree on the fuel pump R&R being an investment. I understand that a 996 with the mileage I have on mine is facing that before too long.

[JFP in PA]

10 hours ago, judgejon said:

Did you ever run a Durametric or piwis test?  What was the code found by your inde shop?

Glad this worked out ok for you.  Fuel pump change over will likely pay off in the long run.

 

I would remain circumspect about replacing the fuel pump; the crank position senor failure causes the fuel pump to shut off when nothing is wrong other than the CPS is bad.

[Kim]

13 hours ago, JFP in PA said:

 

I would remain circumspect about replacing the fuel pump; the crank position senor failure causes the fuel pump to shut off when nothing is wrong other than the CPS is bad.

 

Well, as I pointed out in my original post, the pump was already changed as a "best guess" item. Circumspection won't help much at this point. Having already spent that money, I prefer to assume that the original pump might not have lasted much longer ... after 16 years and 165,000 miles. Helps me sleep better at night

[Kim]

Just to close out this thread, JFP in PA was right on the money. Engine quit again right after my most recent post, and ... as soon as it cooled down ... I started it and drove straight to a top notch local shop. As soon as they heard my tale of woe, one to the mechanics stated, "I bet its the crank position sensor" ... and it was. CPS had a heat sensitive short that  would go away as soon as the car cooled for a few hours.

[JFP in PA]

A common problem.  Glad you got it sorted