GT4 missfire in corners
Discussion
Hi everyone - anyone encountered this problem? Was at Silverstone yesterday, and had a missfire on two occasions. Both right-handers (Stowe and last right in Becketts), both when pushing pretty hard. Significant loss of power and sounded like it might be on 3 not 6 cylinders. Car ran fine for 3 or 4 sessions after the first occurrence; after the second I decided to quit while I was ahead and go home. Car ran fine on the way home.
Cheers
David
Cheers
David
nudgerwilliams said:
JayK12 said:
Low fuel?
Sorry should have said - not sure first time, but second time was at least half a tank of fuel. Oil level fine. Temps what I normally have on track.David
Maybe Porsche could plug it in and see if there were fuel pressure drops? I'm guessing it would log that.
Edited by JayK12 on Tuesday 23 July 10:55
JayK12 said:
I'm sure the GT4 guys will pop up but it still could be fuel as Im guessing the pump in the middle of the tank, if cornering hard it could still drop fuel causing misfire. The fact its doing it only on right hand bends, and on occasions it does to me sound fuel related.
Maybe Porsche could plug it in and see if there were fuel pressure drops? I'm guessing it would log that.
Thanks - have booked the car in - will see what they findMaybe Porsche could plug it in and see if there were fuel pressure drops? I'm guessing it would log that.
Edited by JayK12 on Tuesday 23 July 10:55
TDT said:
nudgerwilliams said:
Update on this. It’s a faulty crankshaft position sensor. Feeling vindicated in taking the extended warranty!
David
Glad they picked it up. David
What did the misfire sound like or did it occur again on the road?
OPC could see it faulting when they plugged the diagnostics in. Seems there is a known issue there as the first thing they tried was fitting a space to stop the sensor moving, but in my case that didn't fix it so they are now replacing the sensor.
Hi everyone
Update on this as it seems my dealer has finally got to the bottom of this problem after 3 attempts.
I've only had the problem on track as it's triggered at very high revs. Symptoms are that the engine abruptly cuts for a fraction of a second at about 7,500rpm. Feels like you have hit a hard rev limiter. After changing up a gear, the engine pulls cleanly, but typically in the next corner or the corner after it misfires. After backing off for a bit the car will then run normally. The problem does not reappear immediately, but maybe after a couple more laps of normal running, or in the next session.
The diagnostics show it is a crankshaft position sensor issue. The final fix turns out to be getting the combination of the correct spec of CPS and spacer for it to go with the gearbox spec. Apparently the recall gearbox requires a different set of parts from the original one.
I ran the car at Goodwood on Friday morning and whilst it was too damp to really load the car up, I was able to run it up to the red line repeatedly and did not have any hint of a recurrence, so I think it's finally solved.
It's a bit odd I've not seen anyone else report this issue, but sharing here in case anybody else does come across it.
David
Update on this as it seems my dealer has finally got to the bottom of this problem after 3 attempts.
I've only had the problem on track as it's triggered at very high revs. Symptoms are that the engine abruptly cuts for a fraction of a second at about 7,500rpm. Feels like you have hit a hard rev limiter. After changing up a gear, the engine pulls cleanly, but typically in the next corner or the corner after it misfires. After backing off for a bit the car will then run normally. The problem does not reappear immediately, but maybe after a couple more laps of normal running, or in the next session.
The diagnostics show it is a crankshaft position sensor issue. The final fix turns out to be getting the combination of the correct spec of CPS and spacer for it to go with the gearbox spec. Apparently the recall gearbox requires a different set of parts from the original one.
I ran the car at Goodwood on Friday morning and whilst it was too damp to really load the car up, I was able to run it up to the red line repeatedly and did not have any hint of a recurrence, so I think it's finally solved.
It's a bit odd I've not seen anyone else report this issue, but sharing here in case anybody else does come across it.
David
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