Ive been having these problems for a while now, and I cannot find anything that is causing it...

You can see the details of my car in my signature. I have a near completley stock Series 5 13BT engine. (Just HKS Airpod, Exhause modded and Airpump removed).

What I have noticed is that after I warm the car up in the morning and drive it up to operating tempeperature, then give it a bit, it drives very smoothly with alot more power (still not a great deal, but alot more than usual). But after it gets a little warmer, its like driving a bar stool.

Once its warmer, boost only starts to rise at 4500rpm, then creeps upto around 10-12psi, but with no noticable power increase.

The engine also hesitates after gear changes sometimes and shudders at low rpm.


Any suggestions of common problems or anything anyone thinks could cause any of this would be greatly appriciated.

 

Vac leak maybe? If you are boosting and not getting any power from it you have tobe losing the pressure somewhere before the engine I'd think.

 

Could be... Ive looked all around for things like that, but cant find anything...

Anything else it could possibly be?

 

Exhaust leak? Exhaust blockage?