one way BOV? car dies? should this happen?

[94tegRS]

ok, my friend got back form lookign at a car he wants to buy, its a 1990 240SX with a 96 180SX black top SR20DET swapped in with the limited slip as well. the guy says he got the front clip of the cra and then swapped it in, my question is this, when yuo rev it up and let off the gas, the BOV makres the sound but the engine dies, the guiy said this is because the BOV is a one wya and has no return. you have to keep downshifting while slowing down and then in 2d right before you come to a stop since the revs are down if you let off the gas it doesnt die. now if the BOV opened when the throttle plate closed and then had vaccuum pulls the BOV open, then you push the throttle, no more vacuum it should cose, but even if it didnt, the engine would still be able to get air, I mean the engine would still want it even if it wasnt pressurized air right. I have never owned a turbo car, never even worked on one but this didnt sound right to me, and my friedn says the guy knew what he was talking and believes him. is my friend gonna get screwed or does he just need a new BOV, cuz I guess the car coems with one(but if that was all it was, wouldnt the guy have already done it ot make it easier to sell if thats alls it needs, isnt it like 2 bolts holding it to the piping and a hose from it to the manifold?

[ghostchild316]

I understood most of your post.

Our cars have airflow sensors on then.You need to recirculate the air from the BOV back into the intake system somewhere before the Turbine and after the Airflow sensor.This wouldnt be a problem though if it had a stand alone...

I've never owned a turbocharged car either.I've just done a bunch of research. so when the day finally comes, I will be ready...

[dayna240sx]

I re-affirm what ghoastchild posted..

I would look into obtaining a BOV from GFB (Go fast Bits)

I have one of their BOV's on my WRX and it works great... even though i am not even using the 50/50 function of the valve...


YAAAAAAAAY!!!! for Subaru's superior engine Management! YAAAY!!!

[94tegRS]

ok, but if you recirculate the air from the BOV back into the system before the turbine, you mean like on the intake pipe somewhere between the filter and the intake part of the compresor side? and the car comes with a new one i guess. so does this mean that the sensors are bad, or what? if he doesnt have it hooked up there must not be a place for it, cuz if there was somewherw to divert the air back into the intake pipe and it wasnt hooked up wouldnt tons of dust and shit be going ito that spot.

I mean I guess hell just have to get it and see what happens cuz I cant get pics of it or anything.

[spitz7985]

whats happening is this-
the car sucks in air and the Mass Airflow Sensor reads it, which tells the ecu how much fuel it needs to inject. when the BOV opens, some of that air is suddenly gone, but your ecu still thinks it's there. this causes you to run rich.

that is completely normal on a venting (or as you call it- one-way) BOV. your options are to either recirculate- which means to reroute it before the compressor but after the MAF, or to move the MAF after the BOV. you could also get a standalone system that doesn't use the MAF

if you recirculate and you have an open element cone filter, you will still have a really loud "psssshhhh" noise.

[CrzyMR2T]

its really not that hard to change the bov, but maybe he was just lazy, and didnt feel like messin with it. my bro had a greddy bov on his mr2 turbo that he used to have, and his car always shut down if u didnt keep the revs up, ive driven it before. he said that it was caused by the bov, not the engine or anything, cause his engine didnt do that before he got the bov, he got the bov used from his friend. so i think that guy selling the car to your friend knows what hes talking about.

[94tegRS]

alright, thanks. also he tole me that tghis car is running stock boost and it is "so damn fast". I have seen that the SR20DET isnt that expensive of a swap to attain, does it bolt right in place of the KA24 or what do you have to do, cuz I like the early 90's 240 hatches. wouldnt mind doing this swap cuz the swpa from an importer is cheap, the carsv are cheap... so its a cheap and fast car. also ive only seen 2 places that sell them, what sites would you recomend buyign from?

[SR20DETpower]

its more of an electrical problem with the ECU the anything else. The MAF has said such and such amount of air should be reaching the engine, it already metered it to give the appropriate fuel, but when the engine doesn't get this metered air(bov open) it will stall. Its not a vacume issue, BOV issue, or mechanical issue, its the fact the engine is fooled when it looses air. S-AFC's and other ECU mods can be programed to recognize this and eliminate the stalling found on Open Atmosphere BOV's. Get a S-AFC as a quick fix, or re-route the return line on the BOV before the compressor, after the MAF. If you have an open element type air filter, i.e. K&N Cone Filter, without the regular air box or resonator.... you should still hear a bit of the noise, if thats the effect your looking for.

[Suislide]

Originally Posted by 94tegRS

alright, thanks. also he tole me that tghis car is running stock boost and it is "so damn fast". I have seen that the SR20DET isnt that expensive of a swap to attain, does it bolt right in place of the KA24 or what do you have to do, cuz I like the early 90's 240 hatches. wouldnt mind doing this swap cuz the swpa from an importer is cheap, the carsv are cheap... so its a cheap and fast car. also ive only seen 2 places that sell them, what sites would you recomend buyign from?

do ALOT of research on it before even THINKING of buying this car. check out our FAQ, and check out every single site listed in there and gather every single piece of info you can before you even start seriousley thinking about buying one of these cars.

[94tegRS]

just to restate this, I am not buying the car just wanted to know if my friend was gettign robbed or not? but I am looking at maybe getting one, I am buying an integra firts cuz I know i like them and already have and engine, pisonts, headers, intake for it. but I found around my grandmas house nice high muileage 240 hatches for 2k.
than ill have all the money i would get for my teg up here if I ended up reselling it which would be like 8k for engine swap/misc stuff.

and ill go check the FAQ right now