rasonline

Hi guys

Please help. Have trieed a search but still not sure.

I have a 99 GC8 Impreza WRX Sti. Car has been running at 1,1 bar boost.

Problem: not getting full boost. Only 0.5 or 0.6 bar.

Description:
Yesterday, while driving on freeway at 100km/h, noticed under acceleration that i was only getting 0.5 bar, and that car was not accelerating as hard as i'm used to.

Pulled up on road side, switched car off and then on again. Problem was gone.

Few hours and about 60km later, while giving full throttle from stand still, and revving up to about 6,500rpm the car held back when i changed into 3rd gear.

I felt something didn't seem right so i backed off immediately. Again, now only getting 0.5 bar ~ 0.6 bar boost.

Can't hear any detonation. Still need to check all boost pipes. Running high grade fuel so highly doubt that the fuel is the problem.

any suggestions as to what it could be?

boost piping? sticking dumpvalve? anything else?

gonna check it out tonight

sjwdavies

A friend of mine had this problem on his Ibiza Turbo.

Inconsistent boosting.

Turned out, that one sparkplug was knackered. Maybe worth a looking?

ReggieMY99

Sounds like limp mode, half boost by ecu to protect engine

That MY is known for its dodgy MAF sensor, i would replace it and see if that doesnt help

Also check for pipe leaks around turbo area

rasonline

will have a look at the spark plugs as they are due for replacement soon.

The boost seems exactly half of what i'm used to. Could well be limp mode. will check the MAF sensor. Hope it's nothing bigger than that.

rasonline

Turns out that one of the spark plugs was partially melted. Not sure if this was the cause, or it happened as a result of detonation caused by some other problem.

I also think the 02 sensor needs replacement.

Reset the ECU and had the fault codes 33 and 32.

32 is for the vehicle speed sensor. Have any of you had problems with this?