Hunting

[Hanaldo]

I can see how the overfueling would be caused by having no bov if you are still running the standard ecu. However that would only cause an issue at low throttle/idle/decel, as that is when the ecu would be expecting the bov to be leaking air. If you have an issue throughout the whole fuel map (ie. accelerating), I think that will be because of the aftermarket plenum and turbo. The stock ecu runs rich as all hell when you start messing with the intake. I bet if you restored the factory bov setup, you would still have overfueling issues.

Either way, both those issues can be solved by a tune. I think your next step should be to get a tune-able ecu installed and get it on the dyno, your tuner will quickly be able to identify if the problem is just in your maps or if you have an underlying issue.

[Craved]

question for the OP - can you list what "all supporting mods" are as listed in your first post?

FPR?

Injectors?

are they factory injectors and factory set fuel pressure?

[Hanaldo]

Also is it the factory AFM or a Z32 or other??

[PaulosECR33]

hanaldo... my problem is only on idle/decel so its possible but im going to wait till i get my vipec and tune around it.yes this is my next step to put a tunable ecu on it and i have come to realise this could/probably will help solve my issue and seeing as though i am planning on doing it anyway ill just wait till then. i see how the bov/bypass valve can cause it as well but like i said before i think ill just wait for the computer now afm is standard and i have tried another and no difference, the vipec has a map sensor so i wont have any reversions problems or any other possible afm related issues.

craved... injectors and fpr are standard for the time being i have some 740's to put in ad i have a surge tank with 044 i just need to hook up for when i get the ecu and im planning on keeping the fuel pressure standard as i doubt ill need higher at the power level im aiming for...

thanks for the replies guys

supporting mods are front mount intercooler and exhaust and thats bout it at the moment

Edited October 12, 2011 by PaulosECR33

[zoom]

Is this what it does??

I don't think it's the bov, my money is on the cold idle control valve. Not the same as the AAC valve just by the way, but it's near it. The cold idle control valve is much like a thermostat, it's a piece of thin coiled wire that expands when it gets hot to block the vacuum line. It's very easy to break, and if it get's stuck open then the vacuum line will be constantly open and act like a vacuum leak when the car is hot.

The valve is on a vacuum line coming off the AAC, so try blocking these lines to see if it changes anything. Also try running the car with the AFM unplugged. Try things to change it's symptoms so you can narrow it down.

my r33 seems to have unstable idle when after warmup.

where exactly is the thin wire coil? is the vac line coming out from the bottom of the AAC unit to the air regulator?

thanks

[PaulosECR33]

that is what i blocked off to stop the hunting so me thinks this is it

once i got round to it i put afm in cooler piping just before throttle body and is fixed.. waiting for vipec, not driving as afm is duct taped to throttle body and lovely cut & shut extension wiring for afm atm thanks for ur help peeps.