Hi guys,

First post is not a good one for me Im afraid. Just picked up my MY99 STI6 TypeRA and immediately noticed that the car doesnt boost properly. Not only does it only boost to about 0.5bar in 4th and 5th but the way it builds this minimal boost is very slow and lethargic. The car also idles a bit lumpy and can drop to very low revs from time to time usually when coming to a halt. There is no smoke or strange noises from the turbo so I thought it must just be a MAF sensor being the fragile 99/00 version. However I swapped this for another and the car still doesnt boost. After doing some research I tried other fixes. Cleaned and tested the boost solenoid, checked for leaks and the piping for any mis routed pipes all to no avail. As a last resort I even removed the pipe to the actuator to see if I could get the turbo to boost more as a way of ruling out the whole electrical system being at fault and it still only made 0.4-0.5bar and feels horrible. The car still has an OE downpipe which has probably been added so the car passes the MOT so still has the heat shield on the turbo (which is a VF28 btw). I did however manage to grip the actuator rod with a small pair of grips and did manage to move the arm slightly. The car has a new panel filter in place and has no blockages in the intake.

Im begining to think the turbo is broke but the fact there is no noises or smoke keeps me thinking am I missing something simple. I can only think of one way forward from here. Remove the downpipe and check the wastegate flap is closed on idle and also check the exhaust wheel moves freely and is not covered in oil and check exhaust housing for cracks.

Bearing in mind I have had the actuator arm moving could it still just be a problem with the actuator not closing? The car is in great condition and is really low mileage so Im hoping someone may have another theory that doesnt conclude with a broke turbo??????

Any help would be most appreciated.

Mike

 

As you mention - check the actuator for correct operation - A Mityvac is useful to check the crack pressure.

Also, check the Boost Control Solenoid for correct operation - connect the 2 green connectors under the driver's side of the dash, and the solenoid should operate and emit a clicking noise. Clean the soleniod and related pipework with brake cleaner.

Read the Ecu , to check for any other possible stored fault codes

 

mate all that is ur actuater not boosting properley, all u need is a remap, or even a cheaper way get a manual boost controller cost uto 30 quid on ebay ad boost it to 1 bar