I just got my crossover pipe back in, and now my car boosts full, but about 50% of the time at WOT and full boost the car will suddenly act as though it is fuel cutting at 4-5000 rpm. Ignition system looks good, all sensors connected....the violence makes it feel like a fuel cut, but everything is stock, and the car is obviously not boosting over stock 9-11psi.

Any ideas?

 

I just posted the same

Is it like a sudden hesitation? With backfire sometimes??

Happeneded to me beofre and it was new spark pulg wires needed. Now I think maybe time for new cap/rotor.

 

If it seems like it happens randomly, and at possibly different RPM, it could be the TPS...
Had this happen on my n/a and the 951

 

The TPS sounds like a possible cause....

 

Could a weak battery also?? I.e. not enough power geting to coil/cap, etc.

Or would that be alternator???

My TOS is also fairly new. Although that doesn't mean it might not be your problem swag.

Swag, are you getting popping/backfiring???

 

no backfiring, just a random cut-out that seems to happen mainly when throttle is applied suddenly. I just redid the vac system and maybe erratic fuel pressure from an incorrect vac route? Picking up a new TPS soon, using a borrowed one right now, so i'm sure ill see if it is that or not. the fpr's are sitting on a pressurized vac line that is shared with the bov/boost gauge/manifold banjo. is this incorrect? I felt the fpr's would be operating on manifold absolute pressure....the old lines were already cracked and popped off, so i couldnt see the old route.

again, it feels like an all-cylinder cut, like fuel cut felt in my other modified turbo cars. the alt is new and the battery is strong. washed the engine while it was apart though...maybe water in something?

ill check it out more, any advice is appreciated!

 

here I go again...and EVERYONE thinks this can't POSSIBLElLY be the cause... Check your battery cables ! ALL the way to the ends. Check the + especially. They get old, and will arc as they get too close to the bell housing etc.
Why under full boost? Because they ACTUALLY MOVE! the car squats, then unloads and **** moves...like you bateery cables (not the top where they're connected, the leads. Check it out REALLY WELL. I had three pros look at this issue fopr me until it finally died. 6 bucks later all fixed. I changed TPS, Fuel filter, pump dist cap, plugs, wires, battery, voltage reg. 6 bucks for new + cable.

This is the reason Icesharks cables all sell out.

 

VAC