Overboost protection and engine stalling?
 

Hi!

Since about 2 months, my 951 has what looks like boost or fuel pressure issues. With exactly the same setup (same boost, especially), I had driven the car for more than a year without any overboost protection cutoff.

Then, the car started to stall pretty bad anytime anywhere, at any engine speed. It took beetween 30 seconds and 10 minutes for it to start back, but it started back really well as if nothing had happened before. In order to solve the problem, I decided to change the fuel filter and the DME relay. It partially solved the problem and the car stopped stalling... BUT! Since then, at full throttle in 3rd/4th/5th gear, sometimes there are really hard cutoffs. When the first one occurs, I can't floor it back in 3rd/4th/5th because cutoffs occur more and more easily, sometimes happening even at about 2/3 throttle. On stronger cutoffs, it looks like it really misses fuel. If I try to accelerate back (at any rate, even 1/10 throttle), the rpm drops under 600 RPM and finally stalls. All what I have to do is to turn off the switch, start it back and it then runs really well.

What could cause that?

Thanks alot... Ho and sorry for my bad english hehe.
SmileWavy

Sounds like a problem I had, where under full throttle it would feel like I hit a rev limiter at whatever rpm it decided to quit at... It would only stay 'quit' for a split second, much like the rev limiter, and then it would act normal until I floored it again.
Was the throttle switch :)

Check the hose to the wastegate, make sure it doesn't have a hole, is torn, or completely off.