90 240sx : blow off valve problem?

[Dukemoney63]

ok i just bought a 90 240 w/ a redtop sr20the car will die at very low rpm, not idle, but if i give it a little burst of gas and then completely let off and push the clutch in the engine will rev all the way down to around 200 rpm everytime and sometimes kill

from what i can gather the guy that i bought it from said if you drive it right, it wont die, this means almost never depressing clutch, except when shifting, and engine braking...i would like to fix this problem, he said something like since the car has an atmospheric blowoff (hks) that it is tricking the computer and the computer doesn't know what air/fuel to use so he said i should get a air/fuel management system or put on the stock intake w/o the blow off...i don't want to go back to stock so any help would be greatly appreciated, if you need any more info on mods just let me know:> thx

[Ni2s4s0aSnX]

Like I always say "don't buy a car that's already moded" or "if its got mods, its probably a fraud" or "if its got an sr, its a ****y car"or something like that.

[Dukemoney63]

please post only if u are trying to help, thank you

[onosqv]

ok i just bought a 90 240 w/ a redtop sr20the car will die at very low rpm, not idle, but if i give it a little burst of gas and then completely let off and push the clutch in the engine will rev all the way down to around 200 rpm everytime and sometimes kill

What are the specs on your car? Is it stock red top? What kind of engine management, injectors, etc, etc. We can't help you w/ little to no information.

If the only difference between your setup and a stock sr20det is the bov, then you should at least be able to idle, otherwise you have some serious leaks.

The part w/ the burst of gas & open bov is probably because the ecu is not tuned for open bov. If you don't understand what I just said, I strongly suggest reading the threads & stickies in the turbo sections.

I hope you know how to do basic work/diagnose on turbo'd cars... If not, start searching & reading the stickies.

[Dukemoney63]

"The part w/ the burst of gas & open bov is probably because the ecu is not tuned for open bov. If you don't understand what I just said, I stronly suggest reading the threads & stickies in the turbo sections."

understand completely and that's what i was thinking...

-sr20det redtop-apexi n1-apexi intake-stock turbo at 10psi-300zxtt fuel pump-upgraded smic hotpipe-megan racing turbo manny-megan racing downpipe-megan racing testpipe

those are the mods it has if it changes anything, so i just need to get it tuned...the only question is where? i'm in middle of iowa, i could drive to chicago or something but would it be easier to send the ecu somewhere? or could i just get some kind of fuel management or something? thx!

[onosqv]

Well, the thing is, I don't think most tuned ecu's (from stock ones) can be setup to work w/ open bov... You need a safc, standalone, or blow-thru setup.

I was rushing and meant you'd need a tune if you have like larger injectors, which would cause your car to run overly rich - combine that w/ the open bov when it goes off & you're piled in fuel w/ no air.

The mods you have now don't really call for a tune (to increase hp, not to fix problems) unless things are already work correctly, which they aren't.

I don't know how much of the stock stuff he gave you or what you have access to - but do 2 things:

1) Check for boost leaks - this is a killer for a lot of guys, some problems that take weeks to figure out end up w/ a simple poorly connected ic pipe.

2) Recirculate your bov - stock is recicurlated, so make it recirc first to see if that helps, which it should significantly.

After you have completed those 2 steps, we'll see where everything stands.

[Dukemoney63]

the guy that had it before me told me it worked perfect with the stock intake (recirc), i don't know of any leaks and to tell you the truth i wouldn't know how to check besides listening (i come from a n/a 350 iroc so turbos/ics are new to me) and i've been looking at fcs but the only difference i can really see is colors and brands, it seems they all do about the same thing...suggestions?

[onosqv]

suggestions?

I strongly suggest reading the threads & stickies in the turbo sections.