I've just had the rocker cover gaskets changed at a garage on my 1995 STI, after it was done it lost power at around 4000 rpm, its irregular and will accelerate gradually to the redline, when you put your foot flat to the floor it splutters and is being held back by something, the garage are still looking but aren't having any joy, has anyone suffered anything similar or offer any explaination, greatly appreciated, cheers ollie

 

Sounds like one of your spark plug leads could be earthing as it tends to happen as the revs get higher and as rockers have been disturbed. Might need new leads.

 

coilpack no longer working after being disturbed, or not properly reconnected.

Does it drive okay off boost, or does it have virtually no power at all?

Paul

 

Its fine low down, just when it gets going, only with full hammer but its not consistant, thanks for your help, ollie

 

You may want to check the compression on all cylinders............