Boost problems

[Stuiegti]

I have a problem with my mk5 gti bwa it has low boost and is only boosting 5psi and only revs to 6k rpm I chaged the turbo dv valve and n75 made no difrance I tuck car to a garage checked all fuse and there fine the garage said maybe could be timing or injectors so instead of just hoping money at anything I just bought a full complete engine the only thing I used of old engine was harness and the car is still doing same think as old engine would a faulty engine harness cause this problem the car runs good and drives itdose not misfire or anything it dose boost a little bit but nothing what it should I am just running out of options now the only thing that has not been changed is engine harness and there is no fault codes with vcds please help

[breeze]

Did you reuse the original boost piping? Could be a leak in that. If no codes in VCDS maybe try a smoke test. I suspect a specialist VW garage could find it very quickly.

I'm not familiar with engine harnesses being an issue.

[Stuiegti]

I did I don't believe its a boost leak as its pulling timing in vcds

[Octoparrot]

Well if replacing the engine didn't fix it, replace the rest of the car and see if that cures it.

[pudding]

Even standard ones pull timing. What numbers did you see?

What was the boost solenoid (N75) duty cycle and what max throttle position did you see?  If the ECU isn't happy with something, it will back the boost off and limit the throttle opening, as well as excessive timing pull (15+ KW).