when i bought my 240 i was told that it had a vacuum leak. after looking over the engine many times and checking all hoses and lines i cant find anything. my sr20 has an old school hks sqv on it, and im thinking this could be the problem.
the idle is very lumpy and rarely ever evens out. when i rev it up, even before i hit boost when it drops back down it stalls, or becomes very close to it.
the bov is recirculating and there are 2 lines going from the BOV to a T then to the intake manifold. when i take off one of the lines the idle is fixed, but all the air is being sucked through the line, so when i put a finger over the line it almost stalls out.
do i just need a new blow off valve? or is mine set up wrong?
Sounds like a set up issue. If you have a recirculated BOV, there should be no “T” in the intake manifold. The recirculated line is supposed to go into your factory rubber intake piping downstream (after) the MAS air flow sensor. There should be a connection about 5/8 to an 1". Take some pictures of the plumbing and post it.
as you can see there are 2 vacuum lines going to the “T” then that goes to the IM. when i take one of those lines off and let it suck air freely the engine runs good, but the BOV doesnt work and i get turbo flutter. in the pic you can see that there is nothing going to that rubber hose, and its blocked off. what would go to this?
if this stalls once the engine gets hot then its you BOV
had a similar problem with my HKS SSQV,
when the car is cold. u rip it or rev it, blows off and car will idle. once engine gets warmed up everything in the engine bay is hot. then it’ll stall.
so this could help you. with HKS bovs, there is a shaft inside the bov that makes it blow off. so i took the ssqv apart, use fine sand paper sanded it a bit, lube it with WD40, problem fixed.
reason being is the shaft gets hot and expands and get stuck and once it blows off the bov stays open causing your car to stall. so sand the shaft a bit
this was my experience. hope it helps
and from your picture your vacuum lines are T-ed so many times…it could be an issue, and im not sure why your BOV has 2 vacuum ports, most bov has 1. so get a new one and dont get a HKS cuz it sux and sounds rice
it doesnt get worse or better when the engine temp changes. id say when i first start it is the worst, because it takes a while for the idle to find the right spot and even out. i dont know thy it has two ports either, thats why i tried taking one out, im thinking of just getting a new BOV cus this ones really old. but then i rev it up and let off i can see the blow off valve open then close.
also when i unplug one of those lines the BOV stops working… if that means anything?
Those old HKS blowoff valves are terrible. They all do that. It never stays shut when its supposed to. Easiest solution is to get an oem valve or a good aftermarket one. There is no point in playing around with those 2 vacuum fittings.
ya thats what i figured. is air supposed to be sucking through those lines all the time? because when theyre hooked up no airs going through
bro i just got a brand new hks sqv 4 and it’s vented out makes a sweet noise and no problems what so ever no idle drop what so ever go grab one and problem solved