Boost cutting out, help needed.

[Jeffer]

Need some help, please!!!!

When driving WOT it seems that the wastegate is opening and shutting fast to prevent the boost from exceeding 1,2 / 1,3 bar. I did the pressure test, and everything was ok. Got a new Forge pop-off valve so thats outruled aswell.

So it has te be (i think) in the software. I've also changed the MAF and replaced feulpump and filters.
Now I didn't replace the Lamda, but I will try that soon.
Hope anybody can give me some advise or suggestions.

Thanks,
Jeffer

[Pisobiker]

Jeffer, couldn't be the ECU backing off for some reason? Might be a dodgy sensor somewhere (like the Multifunction temp. one). Did you try to pull fault codes out?

[Jeffer]

I've already tested the computer with a standard 3b computer. But that doesn't seem to work either. I've also tried faultcodes, but he gave me 4444. So that's nothing aswell.
Is there any way to check the WGFV?

I think I put my money on that or the lamba.

[Jeffer]

I've already tested the computer with a standard 3b computer. But that doesn't seem to work either. I've also tried faultcodes, but he gave me 4444. So that's nothing aswell.
Is there any way to check the WGFV?

I think I put my money on that or the lamba.

[Jeffer]

Now it starts ideling poor and i can't reach 0,5 bar pressure.
And on top of that it runs poor and hasitates to 2500 rpm.
:confused:

[Pisobiker]

Try the lambda then. I had a rough idlingsome time ago as well as increased fuel consumption. Put a new lambda probe and everything was fine again.

By the way, to test the multifunction temp. sensor (the "big" plug on the water rail) just disconnect it. Water temp. gauge on the dash won't work, then, but if the sensor is faulty your boost shoud come back.


Marco

[Jeffer]

Thanks Marco for the help.

I tried everything, replaced everything. 4 days of horror. But I've found it. It were the HT leads.
So in the end I got new sparkplugs, HT leads, distibuter, forge popoff, and a lot off headaches.
But thanks to the forge valve I got way more boost now. I've had to do that 3 years ago, that mod. So there's one postive side to this adventure.

Thanks again.