hi new to this site so here goes. i had brought a wrx 05 plate with a vf34 turbo remapped at scubby clinic from the previous owners running 300bhp according to the data sheets in the files that came with the car.
after 3days of ownership i noticed that it was smoking quite badly so thought it might be the turbo worn so stripped it out to find its ok so next step was i find that its melted piston number 4 due to wrong fuel put in by my son who borrowed it for the day.
after rebuilding the engine forged piston,manley rods etc, put it all back together it runs and sounds fantastic, but it doesnt boost at all usual checks etc but still no boost all pipes new, breathers all clean, turbo ok, just not boosting. turbo switch working have now spent just over £3500 on it and getting to a point where i have no hair left anyone please put me in the right direction to look check etc...when i got the car had a engine light on p2007 but was boosting ok and very quick car after engine rebuild it just doesnt want to boost.... thanks

 

Have you still got EML on or any codes? P2007 should throw it into limp mode?

Did you carry out the rebuild your self?

 

yes EML on code p2007 obd2 scanner reading and yes rebuilt the engine myself im a mechanic for over 30 yrs just took the turbo off and stripped that all blades good and intake runs free ok still has top inter cooler on it put it all back together now and starts ok but wont boost going to check boost solenoid is working next and an air leak test.
if p2007 is comming up when i got the car and it ran ok and boosted ok why would it run into limp mode now the only thing i havent done is have it remapped to the new rebuild yet and the compression is now at 8.4.1

 

Have you kept the TGV system in place when doing the re build. Did they look ok and move freely when you took the manifold off? Clear the code check all the connections on the TGV. Can't tell you why it didn't through it into limp mode though. If the butterfly was stuck closed whilst making boost pressure previously I think that would of contributed to the demise of piston 4 . clear the code see if the problem persists. boost solenoid would be a possibility but generally make some sort of boost pressure even failed ones. Have you tried running just waste gate actuator pressure?

 

yes tgv still fitted have cleared the code but within about 10sec comes back as same code going to take the inlet off toady to check movement etc

 

Check pre-tension on WG arm is set to 3mm

 

Check turbo is spinning up by blinding off actuator feed completely , drive "carefully" to 3k rpm to see if boost is restored ( it goes without saying that this is to be done only to test that turbo spins up and you have to re-plumb it ).

If it does not and you can confirm that the blades spin freely with some compressed air ( then no metal from the piston got to the turbo bearing).

If boost is restored then you have a electronic boost control / sensor issue.

If its a 2 port BC take it out test to see if if clicks with 12volt , basically if it works you won't be able to blow air down the tube. Good luck

 

ok so took the inlet manifold off and found that one bank on the TGV were stuck closed so did the old removal trick of them all and refitted now running full boost so happy happy thanks guys for the inputs and advice

 

No problem buddy all the best