BAM engined mk2 Golf large hesitation after idling
Hi all hopefully you lot can help me with a problem i've had for some time now.
The car is a mk2 Golf with a 2002 BAM engine in it. It runs standard S3 ECU and has alledgedly never been remapped.
Basically when you come to a standstill for even a second or two and then pull away, there is very little power across all throttle positions and the engine produces an odd sort of blowing noise not like a turbo whistle noise though, the unit still makes boost as the DV (Forge 008 with green spring) still does it's thing although sounds different.
After 5-10 seconds of driving using part throttle normal power is resumed and the car takes off, if I leave it at full throttle while it's misbehaving then it never clears all the way to the redline - until I drive part throttle for a while as mentioned.
If I don't let it come to a stand still I can plant the throttle and all hell breaks loose as it should.
Worth mentioning that if say when I'm driving at 50mph and then let it coast in neutral for a while as if I was at stand still and then accelerate again, it again drives normally.
The fault codes I get are 16487 - maf flow too high and 17963 boost upper limit exceeded
I have done some logs before which I think I still have and can post if necessary
I've leak tested many times and changed the MAF, N75, coils and lambda. Engine also has a brand new genuine turbo, forge TIP, FMIC, JBS cast manifold. The N249 has been removed as have the carbon can - utilises catch can, it also has a phenolic inlet gasket.
Sorry for the long post but I know how hard it is to diagnose a problem like this remotely.