[Mk2] [Turbo] Got boost but no power

[killerferret666]

The car seems to boost and sometimes is normal, other times it's like there is no power.

I have a boost controller and the gauge is showing boost of 1.2bar, when the car has power and doesn't.
It is a rev3.

No nginr codes other than 42 and 47 which I expect as I don't have ABS on the car and the car was running fine before with these codes.

I did have the ECU repaired recently, could this still be faulty.

If it's a boost leak would it still be able to get to 1.2bar.

[rossonza]

Checked wastegate actuator movement?

[killerferret666]

Would I be showing boost though if the actuator was stuck open?
I can feel the slight increase in power just not as much as normal

I went round and did up all hoses a bit more last night. What vacuum pressure is there meant to be at idle?

[chrismit]

The fact its showing that you have 1.2 bar of boost on both runs where you have power or not would suggest its not a boost issue to me as its reaching what I guess is your regular boost amount? Unless the gauge is whacky.

Wastegate movement wouldn't have anything to do with that. An open wastegate you would struggle to reach peak boost till later in the rev range if at all as it would all be dumped out the exhaust. If it was shut completely you would be overboosting.

Do you have an AFR gauge in the car?

Same boost but less power maybe an intermittent issue with spark or fueling?

Also it has been quite hot recently, so cold morning air vs general hot weather the air is not as dense, and it is noticeable

[killerferret666]

found the cause of this last weekend.

The turbo to manifold gasket was shot, massive leaks... but still behaving weirdly and correctly on different occasions.

The reason for this was I had a turbo blanket on, so sometimes it would clog the leak enough to allow the boost to build quicker and of course this means the car wouldn't run as rich at that point as it wasn't leaking, other times it would just leak.


When idling it was running very rich, I did chuck on a new Lambda sensor as well, but either way it seems to be behaving now.

[rossonza]

found the cause of this last weekend.

The turbo to manifold gasket was shot, massive leaks... but still behaving weirdly and correctly on different occasions.

The reason for this was I had a turbo blanket on, so sometimes it would clog the leak enough to allow the boost to build quicker and of course this means the car wouldn't run as rich at that point as it wasn't leaking, other times it would just leak.


When idling it was running very rich, I did chuck on a new Lambda sensor as well, but either way it seems to be behaving now.

bloody hell good work. glad you found the cause