boost is fluctuating at full boost/sometimes boost problem

[Ws2]

Only at full boost (1,4-1,5 bar) the boost is quick fluctuating according to the boost gauge between 1,3-1,5bar.

It seems like the effect is greater when it's cold outside.

Is this normal?


The engine is running great, but sometimes boost is reduced to 0.5bar.
After a restart, the engine is running great again.



WGFV, DV are renewed, pressure hoses are o.k, no fault codes


The car is a stock s2 3b with mtm chip (262hp) and open airfilter.


Any idea what it can be?


Thanx!

[YELL MAN]

Try cleaning the MAF maybe? It solved boost issues for me.

[Ws2]

Thanks, i'm going to try it!

[s2_bo]

Only at full boost (1,4-1,5 bar) the boost is quick fluctuating according to the boost gauge between 1,3-1,5bar.

It seems like the effect is greater when it's cold outside.

Is this normal?


The engine is running great, but sometimes boost is reduced to 0.5bar.
After a restart, the engine is running great again.



WGFV, DV are renewed, pressure hoses are o.k, no fault codes




The car is a stock s2 3b with mtm chip (262hp) and open airfilter.


Any idea what it can be?


Thanx!

I had exactly the same problem - it kept getting worse and worse.

It would boost to 1.4 -1.5 bar then after a few minutes cut right down to .5 and not go any higher until engine restart.

I also replaced:
WGFV
MFTS
ARS
etc etc..


Turns out it was the knock sensors.

I replaced them both (one had completely bare cable showing.)

Now its fine again.

I would try that if i was you.

Good Luck.,


Cheers.
Bo

[Ws2]

It's not getting worse and worse, it's more from time to time, mostly it happened on the highway driving at normal speed, never under full load.


But i'm going to check it!

[terrybullwon]

Lmao, i have the same problem in 5th gear at 22psi the gauge flutters at 100-120mph and you get a stutering induction noise and the aceleration gets a little lumpy.

BUT the car pulls like nutts all the way through 1,2,3 and 4th untill you come on to 100mph

[terrybullwon]

I have just got my wgfv and i will let you know if this makes any difference

James

[smogthemog]

Does Boots sell IPAlchohol for cleaning MAF's ?

Jim

[newsh]

Brake cleaner is mostly IPA

[smogthemog]

I thought most brake cleaners were Trichloroethane based

[terrybullwon]

not solved with a new wgfv

[LHD_Kid]

not solved with a new wgfv

Just wondering if any of the above was sorted out...?

[Ws2]

With the cold weather the boost problem is gone for so far.

Thats why i suspect the knock sensors, must check them still, but just cleaned the maf.


And the boost is still fluctuating quick at full (over)boost, but don't think it is bad, the car is running fine.