captainbilly

A guy that I work with has a 2.7t with an APR ECMS chip. He has had it for a couple of years and has had no problems with it until recently. Now when he hits about 4000 rpm, at full throttle, the engine has so little power that the car pretty much stops accellerating. I have driven it and it feels almost like a speed limiter is kicking in (although I am sure that's not the case), the power just suddenly goes almost to zero. When the ECMS is switched to stock the car runs normally.

Again, this just started to happen recently so it's clearly not a firmware issue because the chip is capable of working properly. I think I might hear an air leak when he is at full throttle and mid RPM (just below where the power starts to die) but I'm not sure. I am a bit wary about attributing the power loss to an air leak because there seems to be no problem at all when running in stock mode but virtually zero power in chipped mode (over 4000 rpm). Any ideas or similar experiences?

Ming 2.7T

Pull off the TBB, all the way off. Then inspect it real close. A tear maybe forming. Under stock boost the tear isnt noticeable yet, but under chipped boost, the TBB bulges more and the tear maybe opened. Tends to get worse and it will blow a huge tear at sometime. Again just a guess, have seen this happen before and sometimes it was the torn TBB. Sounds kinda like a vacuum / air leak. Sometimes you also can hear a 'whoosh' sound when you go WOT.

GIACUser

Ming is right... Pull TBB off car completely and inspect.

letitsnow

A friend bought an apr chipped 2.7t and had the identical problem, he had inadvertently switched to the valet mode. This is boost and speed limited to about 50mph, abover which the fuel is cut momentarily.

Hold down the the cruise button longer to see if another program comes up. Check the goapr.com site for further information on changing programs on the apr ecms.

If the car works fine in stock mode, I doubt any mechanical problem, don't start pulling things apart until you check this simple possibility.

Good luck.

LCP

...mine started to feel like that before my second failure and it got worse over about a week before it completely failed.

2.7tDallas

might be a blown IC hose also

StoneMan

If not, probably an air leak somewhere.

Oh, such is the bane of turbo engines!

gigford

Very old topic but might help to someone who experiencing the same problem:
I gone through the same and i can tell the EGT sensor electronic board failure causing this bog over 4000rpm.With standard boost the ECU not limiting the rpm/boost over 4000 but when you mod the ECU the boost exceed that limit and the ECU intervenes if those boards sending the wrong temp data. I had to replace both boards, afterwards no bog happened again.

clancy

Wow. Knew that bad EGTs invoked a deliberate detune but not to that extent. Must be something to do with the performance chip.