I have a 2000 1.8T Passat and have recently developed a problem with the engine. Under acceleration the engine will dramatically loose power (stutter) and will also not boost, especially under stress (low revs, high gear). It will boost sometimes but nearly always has this very uneven acceleration and bad vibration. If I boot it I can overcome some of this roughness but still not get boost.
I took it to VW for diagnosis who said they realised there was a problem but couldn't get any fault codes off it because it has a K&N induction kit installed! Is this true? Has anyone else found this problem?
I'm left with the dilemna of having to install my original airbox just to get it diagnosed! Which may not even help much, but I have no idea what is causing this.
I have replaced my spark plugs, cleaned out the DV (which had oil in it but I am told this is the norm), put fuel cleaner through the system, replaced a vacuum hose which had a tear in the thread covering it - which strangely seamed to improve it a bit only for it to go back to the way it was. I reset the ECU today, which has had no effect.
I have read losts of threads about this sort of problem but they all seam to be slightly different from mine.
Any ideas? Thanks in advance.