996tt boost issue 3 - 4k rpms?

Hi all, been lurking for some time and posted a newbie thread a while ago. My car is a 2001 turbo and is not quite right. I have read various threads both here and 6speed etc but can't find any answers so though I'd ask for ideas. (It will be going to my indy soon) The car had a remap before my purchase from pendle. It will boost in any gear to 3000 rpm showing .6 bar or more but between 3 and 4 k it loses power and feels like you've hit a wall. I had a fault code a month ago and the indy said it was an air leak, could be a hose, cleared it and it has stayed off. The car has forge dv's (again already fitted). The bit that baffles me is it only seems to be at the rev range indicated, this seems to me to potentially be map issue but my knowledge is fairly limited. The car is completely driveable, I just can't put my foot down. I decided to replicate the problem to make sure it is every time and had a flashing engine light, I know this is considered very bad, as soon as I let my foot off it went to normal, no messages etc. Any suggestions/comments before I go to my indy would be much appreciated. Cheers Marc

0.6 bar is standard 996tt boost. A mapped non X50 should boost between 0.8 - 1.0. Has the car always been like this or has this fault only just developed? If it is recent it could be the coil packs or the MAF. When you say it feels like you have hit a wall under full throttle does the car hesitate badly and almost seem to backfire?

It is a recent problem, the car would boost past .6 and has, it just runs out of revs, ie hits 3000 before I can get more boost. I'm being gentle with it at the moment. Yes it does hesitate very badly and seem to backfire.

First thing to do is get a diagnostic check done and see if there are any fault codes. Without them you are shooting in the dark.

That's the problem, when I had it in before the only code was air leak and that was cleared :? , will get it back to them to see the latest code, just after some wisom

Thing is, it might be a completely different code. As Dave says, MAF and Coil Packs are possible candidates, but the fault codes would give you more idea. Pressure leaks can cause the DME to go into a protected mode, which limits boost (on a standard car) to 0.4 bar. Maybe that is happening to yours, and Pendle have raised the limit. If you have previously had a leak, and just had the code cleared without fixing it, then that might be your problem.

I will get the code read asap. The car will happily rev to 5k off boost, I have got a complete set of turbo hoses and new dv so will get those on to eliminate one potential issue. thanks for the comments so far

It's your call obviously but I would be inclined to get the code(s) read before I started changing things around

Turbo Boost On a fairly good day eg one thats fairly cool so the air is denser a 996 turbo should indicate .8 of a bar at full throttle and keep that pressure. I would expect a mapped one to indicate up to 1.2 bar when floored but drop back to 1 bar and hold it. Sounds like diverter valves/air leak / or wasgate actuators. The engine warning light flashing indicates missfire on one or more cylinders and stops flashing when you take the load off the engine so its missfiring under high load. You need to get this vehicle checked as it sounds like you have a few issues.

The car will boost past .6, it just has an issue around the rev range as mentioned. I will get it to my indy asap and see what's going on and report back. cheers marc