Car wont boost past 6psi

[Darkdax55]

I have a 96 v2 wrx and usually my target boost is 12psi. For the last few months though whenever i hold the boost for 10 seconds or more it cuts power to 6psi and the only way to get it right again is to disconnect the negative battery lead and let it sit for an hour.

I getting rather tired of doing that though. I have tried checking to see if it is throwing any cels but its not. The engine check light just flashes continuously which i gather means no problem.

Any thoughts??

[Marky]

Throwing ideas out there - could be pinging its head off and ecu is pulling boost as a last ditch effort if retarding timing isn\'t working

[Joker]

or boost cut on the ecu is triggered

[Darkdax55]

Im thinking it might have something to do with my blow off valve because once the boost is cut, even when i boost to 6psi, i cant really hear the bov at all. I think i might change back to the factory bov and see if it helps at all

[Marky]

What would the battery have to do with that

[Darkdax55]

Disconnecting the battery resets the ecu

[dean.ryan]

Lol use a can of upper engine cleaner and clean your bcs (Boost control solenoid)..

Otherwise I\'d check your wastegate actuator, my wrx was boosting 9psi(ish) even with just the wastegate connected directly to the pressure nipple on the turbo. Pulled it off and it was like a babies toy, just rattled around and then finally broke lol

Get rid of the boost tap as well if you\'ve got one lol

[Marky]

 Darkdax55 said:

Disconnecting the battery resets the ecu

I get that, but that\'s nothing to do with the bov.

If you have the factory boost control in place still, something is putting it into limp mode. It could be a faulty component, or knock / over boost triggering it. The solenoid is working if you see 12psi, it\'s then being shut off deliberately, i have no idea why though

[Darkdax55]

Yeah i dont get it either. It always comes right after a reset but it never throws any cels.

[ben-jamminn]

I had the same thing on my v7. I\'d get target boost then it would go to 0.5 bar and stay like that until ecu reset. Turned out to be AFM. Incorrect reading causing incorrect fueling, leading to mass det, causing ecu to cut boost. I didn\'t have any codes either..

[Darkdax55]

How did you fix it?

[kamineko]

in this case, borrow a known good Air Flow Meter from your model and test

[Darkdax55]

I just took the afm off and checked it out. It looks good and clean. I only have this problem in 4th and 5th gears going up hill. I have never run into any problems on the flat before so it could be weeks before it happens again.

Im stumped

[twinturboboy]

sounds like det to me - the AFM may not appear to be dirty but it could still be stuffed

[Darkdax55]

What is det.? Sorry i still dont get some of the abbreviations

[Timmah]

 Darkdax55 said:

What is det.? Sorry i still dont get some of the abbreviations

Detonation(Det) is just when the fuel explodes before it\'s meant to.

What fuel do you use?

What is your idle like? Is it stable? A little up and down?

Any mods other than the BoV?

[kamineko]

det is short for detonation.

you need to be more specific about a problem when asking the internet, first you said \'whenever i\' and there is a page of replies, now its \'only in 4th/5th going up hill\'

what modifications / fuel / other issues?

this thread will end up going nowhere. find someone who knows the model, it needs to be checked in person

Timmah bet me to it

[Darkdax55]

I use bp 98 fuel. Idles fines. No other mods. I just took the bov off and reinstalled the factory valve and i seems to be running much better

[ben-jamminn]

I replaced the AFM, your symptoms sound similar to mine, high gears, under load (hills, etc) seriously, find a mate with the same AFM and swap it out, go boost up a hill and see what happens. I was using 98 fuel as well but it was still setting due to ecu not seeing correct air flow