Jump to content
SAU Community

Recommended Posts

Hi all this is my situation.

I have a 96 r33 gtst and when driving and coming to a stop and sometimes whilst driving the car will stall.

Whilst sitting at the light after stopping the idle of the car sometimes sits at 1k or 1.2k or even sometimes

after i have started it again it idles at 2k. If i rev it it drops back to normal 700rpm. Im thinking it may be the AFM.

My car has the following mods: cat back exhaust, bov, boost controller, pod filter. Any feedback would be greatly appreciated.

Price for a new airflow meter if that is the problem?

regards

jim

Link to comment
https://www.sau.com.au/forums/topic/179316-r33-gtst-staling-problem/
Share on other sites

so most probably it has a leak right? or if i can tighten it it will take more pressure to open up.

just a quick question how does the bov controll the idle and stalling. vaccum leaks i guess

No, it wont have a leak. Its just ATMO venting.

The AFM (near your pod) normally has the air re-circ back to it. The ECU expects it to be there and buy installing a pointless Atmo BOV, your sending the ECU into a fit.

To fix the problem for good you have two options.

1. Put the stock BOV back on (less than $100)

2. Purchase some management, pay for a tune (potentially over $1500)

BOV's are a pointless mod, much like pod filters. They offer not performance gain over the OEM gear, if anything they hinder performance

a bandaid fix for it is to get new spark plugs.

spark plugs?? i had the same problem the factory bov (when run in atmo)is held open a little by vaccum from the manifold which basically intoduces a leak into the intake system, the engine is taking in unmetered air, if it is adjustable just tighten it a little other wise vent it back and you shouldnt have a problem.

Edited by drf76
spark plugs?? i had the same problem the factory bov is held open a little by vaccum from the manifold which basically intoduces a leak into the intake system, the engine is taking in unmetered air, if it is adjustable just tighten it a little other wise vent it back and you shouldnt have a problem.

If it were a factory BOV you wouldn't have aproblem if it were open at idle for letting in unmetered air, as it'd just be allowing the same metered air to travel a different path INTO the engine.

If it were a factory BOV you wouldn't have aproblem if it were open at idle for letting in unmetered air, as it'd just be allowing the same metered air to travel a different path INTO the engine.

i always thought that it would cancel out due to the air being sucked into the turbo and air being blow out towards the throttle body pipe where the bov is mounted, taking of the bov recirc pipe stuffs the balance and causes air to be drawn in, its just like having a pcv valve connected with a catch tank that is vented, it would cause a vac leak through the rocker cover, thats why near the bov recirc pipe you have the breather for the rocker cover into the intake pipe (near the afmeter) to stop a vac leak to the manifold.

i always thought that it would cancel out due to the air being sucked into the turbo and air being blow out towards the throttle body pipe where the bov is mounted, taking of the bov recirc pipe stuffs the balance and causes air to be drawn in, its just like having a pcv valve connected with a catch tank that is vented, it would cause a vac leak through the rocker cover, thats why near the bov recirc pipe you have the breather for the rocker cover into the intake pipe (near the afmeter) to stop a vac leak to the manifold.

Turbo does nothing at idle.

Air comes in through AFM, through turbo, through throttle, into manifold.

If BOV is open

Air comes through AFM, through turbo (And also through the recirc pipe and comes out just before the throttle) and then into manifold.

Whilst the car is in vacuum. Air is being SUCKED not forced through the intake.

Turbo does nothing at idle.

Air comes in through AFM, through turbo, through throttle, into manifold.

If BOV is open

Air comes through AFM, through turbo (And also through the recirc pipe and comes out just before the throttle) and then into manifold.

Whilst the car is in vacuum. Air is being SUCKED not forced through the intake.

i know air is not forced into the intake lol wrong wording, its not on boost at idle, the suction before and after the turbo cancels out when you have the recircirc pipe connected so no air is being drawn through the bov, put it this way would it be good to have a small hole in the intercooler piping which is wat the bov is basically doing.

i know air is not forced into the intake lol wrong wording, its not on boost at idle, the suction before and after the turbo cancels out when you have the recircirc pipe connected so no air is being drawn through the bov, put it this way would it be good to have a small hole in the intercooler piping which is wat the bov is basically doing.

If there's a recirc ppipe, then that's like saying, with a hole in the intercooler piping, put an AFM so the ECU knows.

The air, even if the engine is pulling air through the BOV from the recirc pipe, the recirc pipe is still AFTER the AFM, therefore, it's affectively just "changing lanes" but it still went through the toll

If there's a recirc ppipe, then that's like saying, with a hole in the intercooler piping, put an AFM so the ECU knows.

no its only there on idle due to the high vacumm, so its sealed under boost, im just saying at idle low rpm with vacumm. Its too hard to explain, its exacltly the same a have a pcv valve with a vented catch tank almost the same thing. By the way Im basing this if the factory bov is run to the atmoshpere, i understand that if it run with a recirc pipe there is no difference it just taking a different path still to the throttle body, i think there was a misunderstanding MBS206

Edited by drf76
no its only there on idle due to the high vacumm, so its sealed under boost, im just saying at idle low rpm with vacumm. Its too hard to explain, its exacltly the same a have a pcv valve with a vented catch tank almost the same thing. By the way Im basing this if the factory bov is run to the atmoshpere, i understand that if it run with a recirc pipe there is no difference it just taking a different path still to the throttle body, i think there was a misunderstanding MBS206

If there's no recirc pipe, that's most likely one of the huge issues.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Yeah, it's getting like that, my daughter is coming over on Thursday to help me remove the bonnet so I can install the Carbuilders underbonnet stuff,  I might get her to give me a hand and remove the hardtop, maybe, because on really hot days the detachable hardtop helps the aircon keep the interior cool, the heat just punches straight through to rag top I also don't have enough hair for the "wind in the hair" experience, so there is that....LOL
    • Could be falling edge/rising edge is set wrong. Are you getting sync errors?
    • On BMWs what I do because I'm more confident that I can't instantly crush the pinch welds and do thousands of USD in chassis damage is use a set of rubber jacking pads designed to protect the chassis/plastic adapter and raise a corner of the car, place the aforementioned 2x12 inch wooden planks under a tire, drop the car, then this normally gives me enough clearance to get to the front central jack point. If you don't need it to be a ramp it only needs to be 1-1.5 feet long. On my R33 I do not trust the pinch welds to tolerate any of this so I drive up on the ramps. Before then when I had to get a new floor jack that no longer cleared the front lip I removed it to get enough clearance to put the jack under it. Once you're on the ramps once you simply never let the car down to the ground. It lives on the ramps or on jack stands.
    • Nah. You need 2x taps for anything that you cannot pass the tap all the way through. And even then, there's a point in response to the above which I will come back to. The 2x taps are 1x tapered for starting, and 1x plug tap for working to the bottom of blind holes. That block's port is effectively a blind hole from the perspective of the tap. The tapered tap/tapered thread response. You don't ever leave a female hole tapered. They are supposed to be parallel, hence the wide section of a tapered tap being parallel, the existince of plug taps, etc. The male is tapered so that it will eventually get too fat for the female thread, and yes, there is some risk if the tapped length of the female hole doesn't offer enough threads, that it will not lock up very nicely. But you can always buzz off the extra length on the male thread, and the tape is very good at adding bulk to the joint.
    • Nice....looking forward to that update
×
×
  • Create New...