My 95 940 turbo runs great until you accelerate hard. At about 3500 rpms under hard acceleration, it begins to whistle and the acceleration stops as if there is a rev limiter. Does this every time. I had the back pressure of the cat tested and it was fine and I can't locate any vacuum leaks. I bought the car last year with only 21k miles on it and think it had been sitting for awhile. All of the 30k mile tuneup has been performed. Possibly a wastegate problem? Thanks for any suggestions.

 

2 things that come to mind: fuel pressure, or small crack somewhere in the intercooler piping...

 

I recently had the fuel pressure regulator replaced due to intermittent starting difficulty. I'll take a closer look at the intercooler piping. thanks

 

This is just my feelings on it, but could the wastegate be stuck closed? Then you would over-boost the engine and the over-booster safety would kick in. Is the turbo gauge showing more boost or going outside or it's normal full boost position? When the intake pressure hits around 14psi a switch turns off the fuel pumps.

 

Titan Joe,

That sounds exactly like the problem. The car dosn't have a boost gauge however, so I can't verify by that. Any suggestions on how to repair (by a shade tree mechanic) or should I take it in for repair/replacement. I would prefer to repair it because the car has so few miles.

Thanks