Wondering if anyone has any experience with 1.8t boost fluctuation, and might be able to point me in a direction for fixing the symptom. Any advice is much appreciated. The problem as I can best describe:
Car: 2003 Anniv GTI - AWP - bought new - ALWAYS 93 octane, ALWAYS synthetic (not that I think that's related).
The symptom first appeared maybe a year or so ago and would only appear rarely (once a month maybe), and usually only when the car was warming up and driving out first thing of the day. When I would pull out in 1st gear, giving it a little throttle, when I would let off the pedal a hair I would feel an ABRUPT drop in deceleration just for a second. Like the boost disappeared for a moment. Where the car normally just smoothly backs off / slows down.
It happened so rarely and was so minor, I didn't pay it much mind.
The other day I decided to flash with car with a 93 APR map (finally, at 95k. Don't ask )
Now, that same symptom described above, can be felt more regularly, and can almost be created upon request: If I'm in say 3rd gear at maybe 2000 to 2500 rpm, then put the pedal down maybe 3/4 to build some decent boost, when I let off a hair, but hold the pedal and remain in gear, I can feel a weird stutter or abrupt momentary drop in what I'm perceiving as boost pressure. In other words, it seems to be the same issue I was previously only having on rare cold/startup situations.
Maybe the higher boost and or increased ignition timing is bringing the issue more to light?
The DV was replaced a while ago with the better 228 TT DV, and is holding vacuum fine.
- Someone suggested maybe it's misfires, and maybe start by changing the plugs.
- Anyone have any insights, or has seem this issue in these motors before?
Many thanks in advance!