davefl1976

I’ve got a very intermittent (half a dozen times in the past year) stalling problem that I’d like to run by you folks.

It’s a 2010 997.2S cabrio, and every so often it’ll stall out when the car’s coming off throttle. To give you a scenario, the last time it happened I was at a stoplight. The light turned green. I accelerated not fast, but ‘peppy’ like I always do, and the next light in front of me turned yellow so I put the clutch in to brake and slow down and the engine died.

Time few times before that were under similar circumstances. It’s always when I’m coming off throttle. It’s never stalled out while idling, or cruising, and it’s never taken more than a second of cranking to get the engine started. The scariest time it's stalled was in mid turn, because I lose power steering and power brakes. That adds some excitement to the trip.

I’ve discovered that I can put it into the appropriate gear while I’m in motion and pop the clutch to get it restarted. This is much more preferable than having to come to a stop in traffic, take the key out, put it back in and crank the engine.

Things I’ve tried so far:
- New air filter
- New MAF
- Cleaned throttle body

I’ve taken it to the dealer right after a stalling episode and they can’t find any codes at all.

They tell me that when it was new, it received the updated HPFP from the service bulletin in 2010. I’ve read up on how the car behaves when the HPFP is bad (long crank time, sluggish speed) and it doesn’t seem like that’s my symptoms.

Any help is appreciated!

EDIT: One thing I wanted to add is that this has never happened when the engine's up to full operating temperature. It's only ever happened when the engine was cold (in its first few minutes of running in the morning) or warm (being restarted after an hour of sitting in a parking lot).

davefl1976

I've run across a theory that it could be the Crankshaft Position Sensor going bad.
Would this make sense to you folks?
It looks like a relatively cheap, fairly accessible part. Is it a simple swap, or do I have to worry about 'air gap' and sensor adjustments if I choose to swap the part out?

Thanks!

Misdirection

Just to add another data point: I've had this happen about 4 times exactly as described, over the last 4 years. Very, very rare. Always as I have the clutch in and am rolling to a stop at a light/stop sign. No idea the cause. Starts right back up. After the first two times, while the car was still under original factory warranty, the dealer found no codes and said it was probably just electronic (not helpful). It has definitely happened with oil temp up (after getting gas after a long drive was the last time). 997.2 C2S 6-speed. Otherwise car has been flawless for the duration of my ownership.

davefl1976

Sounds like we've got the same gremlin in our cars.
It's sort of a nagging thing that I can't get out of my head. I just expect it to stall any given time I put in the clutch. It's only happened half a dozen times, but it takes enjoyment away. It also makes me not want to let my wife drive the car, because what happens if she's coasting through a turn and loses power steering and brakes?...

Ginsu Tim

idle control valve?

jstorii

2006 C2S
Same exact sypmtons started a week or so ago. Random engine shut off when stopped, recently hesitation or missing in 1st or 2nd gear from stop, also notice tach is bouncing a litttle.
OBDII Code P0335, crankshaft postion sensor "A" circuit issue.

Has anyone replaced the crankshaft position sensor when these symptons occur?
Any DIY info on the crankshaft position sensor?

thanks

freshazmi

Having the same issue with my 997.2; did you ever solve the mystery?