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okay so the problem started today. my wife was driving the beast to work and called me to tell me that it would turn off at stop lights..... if she holds the gas the car does stay on but you gotta hold the gas or else it just dies out.... she says no loss of power, spools up good but it just dies at stops.... keep in mind the fuel pump is pretty much new .... the rest of my mods are listed on my sig.....

i put in the afpr about 2 months ago and been running good.... since the car had been boosted it had always idled wierd... it will drop rpms to 500 and come back up slowly.... any ideas... thanks for you time guys...


i have not checked the car since i am on a 24 hour shift right now but i just needed you guys to help me out finding a place to start....

Alternator?? Check your IAC and TPS stuff of course.. Basic troubleshooting steps for now.

You let your wife take your boosted mx3 to work. Dude, you must trust her pretty good. I'd be scared doing that lol

mx3autozam wrote:You let your wife take your boosted mx3 to work. Dude, you must trust her pretty good. I'd be scared doing that lol

x2 that rocks... I wish my GF liked driving the mx-3 *sighs*

anyways seems like it's an IAC, TPS issue or vacuum... maybe something simple?

my car always had a droping idle. I think it eventually ended up being the TPS or the VAF. but i would re adjust your idle screw a little bit and run it at like 800 or 900. its probably fouling out the plugs at an idle. "DUH" thats what my issue was. i put in a Blaster 2 coil and the MSD and that fixed the issue. still when runnign the stock ecu you will always run into little strange bumps

I know you believe i dont know s--- about boosted mx3s. But its dies because possibly its running too rich at idle. Even with the ze inhectors, you gotta adjust it. Mine was doing right but it wanted to die. adjusted the adpr and works well.

Also can be something as simple as a vac/boost leak .


What does the wideband read, assuming you already got one.

My idle jumps up and down up and down, wideband rewads like 12 af at idle sometimes.. if i make it more rich it does, make it lean it works best.

also regular tune up wouldnt hurt (if it hasnt been done)

Blow off valve..


What kind do you have and is it leaking to the atmosphere at idle? There are types that require washers or ajusting to make sure the vacuum at idle isnt holding it open. Since you have whats known as a "hot wire" type air flow meter they are known for not liking blow off valves. Try tightening it up and see if it fixes the problem..

Ohh and get a standalone.. Fmus are terrible. Your car will thank you.

thanks for your help guys ...
i checked out the car and well honestly it works perfectly.... i just made sure all the wires were connected right especially that vaf... fuel pressure still at 38 at idle like it always is..... i drove the hell out of it for a while and didnt die once... maybe it just wassent warmed up.... but still i will look into what you guys suggested....

hex i dont have wide band yet and my narrow band doesn't even work... plugs indicate it healthy and ideal....

franko.... bow off valve is an ebay BOV
its this exact one ....

i will try tighting it since it is completly loost... im actually blowing off at idle with my big ol t4.... might be a problem... thanks bro

this is my air flow .... turbo.bov.vaf.tb.

is that correct or do i have something wrong there..... there is no intercooler....


vaccum gauge still reads good above 18 ....

maybe it was just one of those days our cars have. Mine died today when it was cold

is the way i placed my bov the proper order....

hey at idle it shouldnt be blowing.. well at least from what ive seen. check the bov, i think that may be it, adjust the screw on it, i think thats what adjusts it. doesnt mean its bad, just probably needs to be adjusted. Im sure ull be ok tho, if it just happened that one time.

Yeah that will work. Its not really the ideal way though. I just dont like the idea of boosting your vaf. The way that I used to have it and the way that most factory turbo cars are with vaf's (like skylines) is the air filter goes into the vaf, then into the turbo, then through the intercooler up to the blow off valve and then finally into the throttle body. If what you are doing works for ya then more power to you. A factory car will have a recirculating valve to put the air that is blown off between the vaf and the turbo so that when the blow off valve goes off it wont stall the car by making it too rich because the air it thinks was getting used was vented. You can try different combos to see what works best. It shouldn't be too hard to change that around and see if it makes a difference.

*cough* STANDALONE *sniff*... sorry, this darn cold is really killing me here.

And your blow off valve should definitely be closed at idle.. that causes problems... Like stalling

but where our turbo sits its a little complicated to place the Vaf you know what i mean pimp.... can you score some pictures??????

weclome to the world of boost once ur there its all good them comes problems some small some big..

god knows i had my fair share with my boosted MX-3..

but i love that damn car to much to just give up on it. even though some days i just want to bust it with a bat & call it a day. LOL.

but i don't i fix it and enjoy the boost.

PWRD_BY_HKS wrote:but where our turbo sits its a little complicated to place the Vaf you know what i mean pimp.... can you score some pictures??????

My boosted B6T in my old 323... Just to give you an idea of how things should be plummed in... Your piping might run in different places but the order should be the same...

Air filter/Vaf/turbo inlet/charge pipe from turbo out let/intercooler/charge pipe to throttle body... BOV mounted I believe 6 - 8" from the throttle body..



yellow arrow is the intake pipe coming up from the turbo inlet that is connected to the vaf and the air filter connected to the other side of the vaf

Red arrow is the charge pipe coming off the turbo out let into the intercooler

Blue arrow is the charge pipe coming from the intercooler up the the throttle body and my bov is just behind the blue arrow..



Just a picture from the other side of the motor.. you can see where my bov is placed there.. I would put yours closer to the tb away from the exhaust manafold though...