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R33 Gtst Staling Problem

jkotsa

By jkotsa,
in Engines & Forced Induction

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jkotsa Collaborator

jkotsa

Posted
Posted

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

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R31Nismoid Grand Master

R31Nismoid

Posted
Posted
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

drf76 Collaborator

drf76

Posted
Posted (edited)
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
MBS206 Grand Master

MBS206

Posted
Posted
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.

drf76 Collaborator

drf76

Posted
Posted
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.

MBS206 Grand Master

MBS206

Posted
Posted
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.

drf76 Collaborator

drf76

Posted
Posted
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.

MBS206 Grand Master

MBS206

Posted
Posted
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

drf76 Collaborator

drf76

Posted
Posted (edited)
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
MBS206 Grand Master

MBS206

Posted
Posted
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.

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