Golf V 1.9 TDI intermitended boost loss

[ALV_]

Good day

I recently bought a golf V 1.9 TDI (BXE), I bought the car with faulty MAF sensor and replaced the maf sensor and cleared the error code.

Pulling away sometimes I have boost sometimes I do not when the car doesn't go into boost it smokes, the car was then scanned and I got an overboost error, checked for boost leaks and replaced all the charge pipe o-rings checked for vacuum leaks as well

As soon as the MAF sensor is disconnected and I drive the engine light goes on but the car doesn't smoke and makes boost (not as much as it's supposed to)

All that I can think of that can be causing the issue is
-VNT actuator and/or stuck vains
-Vacuum box

If anyone has had similar problems help would really be appreciated

[Ashveer03]

Best thing to do is log the boost with a scan tool, pref vcds. It will give U a proper direction. These turbos are kak anyways, over boosting them shortens their life by alot. Jamming vanes is also common after 200k Kms. All depends how the vehicle was being used.

If the car still has a cat, first step would be to decat it.

Also have a look at the egr. Could be sticking open.

[ALV_]

I'm busy studying so I don't get time to work on the car.
I removed the egr and egr cooler yesterday and cleaned it I'm going to install it today and going to remove the cat ill let you guys know how it it goes

[ALV_]

Evening

I removed the stock turbo and saw that the vnt was messed up it looks like it is corroded so it was causing the vains to get stuck occasionally so I put on a BV39-0083 the 96kw turbo from the sportline and it sounds far better just finished going to test drive it tmrw and make a downpipe and then go tune

[ALV_]

Drove 250 km so far no problems at all cars driving perfect going to have it tuned spoke to a few people they told me I can get about 1.5 bar with now smoke and 320 Nm with my stock injectors

[Ashveer03]

Those Injectors max out smokeless at 1.6bar. Max 120kw 400nm wheel power at the coast, personally tried and tested on a polo AXR engine with a bv39b, AG injectors and fmic.

I would suggest a very mild stage 1 tune, more like eco. BXE engines run bearings very easily, I advise U not to push it or max the injectors out.

Personally on that engine I would prefer 1.4bar with no boost taper.
Would also recommend SR Tuned for tuning.