R32 Gtr Stalling On Idle After Rev

[NoFigJamHere]

Oh n btw ive run an atmo bov on my car since 1999!!! I still have the same car with wait for it...... the same BOV.. Never had the cam covers off since ive had it, did the cambelt and turbo's afew months back and going strong... The MAIN reason manufacturers run a plumb back system is NOISE and emissions/pollution...Not because theyre adding extra fuel for the extra air with the injectors that are actually no active.... Good luck, it will be something odd that time n patience will see you fix it (maybe some bad advice thrown in to)

[The Mafia]

Mr Mafia you seem adament that an atmo BOV on a GTR will 100%, without doubt, put ya house on it cause a rich condition on decel because you are so Knowledgable and a specialist "tuner" but do even know that a GTR shuts the injectors OFF on decel? So your entire thesis/theory on OEM GTR BOVs is how does one say ..... Horse shit!!!!! Hmmmmmm....... And as for SARD fpr's the only times ive ever seen them give trouble is when 1 has been fitted incorrectly or was 1 of the chinese copies that have diaphram issues.... What is your background? ie: where did you learn to tune? Do you have a workshop or do you work as a tuner for a shop? Now to the orig poster i had this excact same issue with my R33 GTR and it turned out to be 1 of the AFMs was shagged. Replaced them both and problem went away. If you can borrow a pair of known good AFMs to try do it asap and save your hair. PS make sure you have the fuel lines going into the correct ports of the fpr, they cannot go either way. Erratic fuel pressure is a major cause of concern imo. Cheers. N if i was you id just ignore Mafia seems like he got a laptop for xmas and now with a few cables he's a "tuner" ...I dont know why he gets so jacked up over something so trivial but im guessing it was because he knew something that nobody else did!!!!

Yes, I do know this about decell.. Yes, I have still seen problems with stalling or hesitating. I cannot stress to people how much they should leave it as close to the factory design as possible,when running AFMs. Any air past the AFMs is measured. If its dumped the ECU does not know about it, and there is a guaranteed rich condition somewhere.

You say that there is a decell cut... That doesn't really mean much, because when the foot is back on the throttle, or the ECU is returning fuel to the engine AFTER the decell cut, to stabilise the idle the ECU still does not have a clue how much air it is mixing fuel with... why? Because it was dumped out of an airleak aka BOV.

So, I say it again - There is still a rich condition there. Guaranteed. I've seen it with my own eyes, MANY times. Why? Because I have a wideband. I've tuned cars for a long time. I've been tuning for nearly 10 years. I've fixed up a lot of dodgy workshop work too. I don't do it for the money - I do it because I LOVE it. Hence why my tunes aren't quick and nasty, without any care or love for the sport.

I said it before - I hate seeing stalling threads where there are ATMO BOVs installed because its a HUGE airleak and always adds to the problem. If people can't understand the simple way this air measurement system works then don't f**k with it.

Why bother looking for all the little airleaks, and hose splits, if you're going to just run a ATMO BOV anyway?

If you are that desperate to run one without hassle, get a MAP sensored ECU.

Anyway, OP, your fuel regulator should not be doing that. At about my 6th SARD fitted car I stopped tuning cars with them fitted. Every time I would do a power run I'd get a different AFR without any adjustments.

Guaranteed every time, once the factory FPR was re-installed all problems went away.

[The Mafia]

The MAIN reason manufacturers run a plumb back system is NOISE and emissions/pollution...Not because theyre adding extra fuel for the extra air with the injectors that are actually no active..

Einstein once said:

"“If you can't explain it simply, you don't understand it well enough”"

And you don't understand how an AFM based system works, so stop talking absolute shit.

Any air measured after the airflow meter cannot be dumped because the ECU has already calculated fuel for it. even AFTER decell...because it is still there.. in the pipes...in the intercooler.. And thats where the ECU expects it to be, because it was designed and programmed that way.....

f**k its like I am talking to retards sometimes.

Edited March 1, 2012 by The Mafia

[Bsa]

Calm down mate everyone isn't into being talked like that did you have a bad week or something? To the op have you triple checked everything is hooked up correctly? I would give the afms a spray with contact cleaner and check solder joints or just try knowen working items.

[Travis32]

Einstein once said:

"“If you can't explain it simply, you don't understand it well enough”"

And you don't understand how an AFM based system works, so stop talking absolute shit.

Any air measured after the airflow meter cannot be dumped because the ECU has already calculated fuel for it. even AFTER decell...because it is still there.. in the pipes...in the intercooler.. And thats where the ECU expects it to be, because it was designed and programmed that way.....

f**k its like I am talking to retards sometimes.

ok so question regarding the excess fuel etc that hasnt been metered.Wat bout the o2 sensor is there purpose to let the ecu know how rich or lean it is? so if this was so the rich goin out the exhaust still should be altered by the ecu? or am i just a loser again

[NoFigJamHere]

Its obvious that the more i reply the more you could potentially learn... And im worried what that could mean for the rest of the users in here. I mean imagine if someone who quotes things like "You say there is a decel cut, that doesnt really mean that much because when the foot is back on the throttle or the ecu is returning fuel to the engine after decel cut to stabilise the idle the ecu still does not have a clue how much air it is mixing fuel with...why? Because it was dumped out of an airleak aka BOV" actually knew something about engines/ecu's. We'd all be in for it then.

OK here goes nuffin...by yours truly the "RETARD" . If your foot is back on the throttle there WONT be any decel fuel cut.....pretty obvious id have thought. And get this the BOV will be closed and by some kind of miracle that airleak you invented isnt there anymore....So please explain why the ecu wont know how much FUEL to mix with the AIR (just incase you werent aware the ecu controls the fuel not the air )and you do realise that the dumped air you value so dearly is already yesterdays news for what the ecu is doing!!! And i do appoligise for failing to mention that not only do you own a LAPTOP and various cables you also own a WIDEBAND im sure that is a critical aspect when refering to you tuning abilities...

I apoligise to the OP for going off topic but i see so much miss information that gets thrown around in here i thought id have an opinion. Nothing worse than doing something you dont need to do because someone got their abilities and ambitions mixed up for a few minutes.

[The Mafia]

Its obvious that the more i reply the more you could potentially learn... And im worried what that could mean for the rest of the users in here. I mean imagine if someone who quotes things like "You say there is a decel cut, that doesnt really mean that much because when the foot is back on the throttle or the ecu is returning fuel to the engine after decel cut to stabilise the idle the ecu still does not have a clue how much air it is mixing fuel with...why? Because it was dumped out of an airleak aka BOV" actually knew something about engines/ecu's. We'd all be in for it then.

OK here goes nuffin...by yours truly the "RETARD" . If your foot is back on the throttle there WONT be any decel fuel cut.....pretty obvious id have thought. And get this the BOV will be closed and by some kind of miracle that airleak you invented isnt there anymore....So please explain why the ecu wont know how much FUEL to mix with the AIR (just incase you werent aware the ecu controls the fuel not the air )and you do realise that the dumped air you value so dearly is already yesterdays news for what the ecu is doing!!! And i do appoligise for failing to mention that not only do you own a LAPTOP and various cables you also own a WIDEBAND im sure that is a critical aspect when refering to you tuning abilities...

I apoligise to the OP for going off topic but i see so much miss information that gets thrown around in here i thought id have an opinion. Nothing worse than doing something you dont need to do because someone got their abilities and ambitions mixed up for a few minutes.

Not even going to bother. You know why? I've been there, tuned heaps, and fixed this problem, and have seen this problem many times in REAL LIFE.

You sir, can keyboard warrior all you like.

There is nothing more obvious than experiencing it in REAL LIFE.

And, what you are saying is going against how Nissan designed the system. So lets leave it at this, I'm wrong, Nissan is wrong, and you're a dickhead and think that you're right about everything.

Good luck in life.

Edited March 1, 2012 by The Mafia

[The Mafia]

ok so question regarding the excess fuel etc that hasnt been metered.Wat bout the o2 sensor is there purpose to let the ecu know how rich or lean it is? so if this was so the rich goin out the exhaust still should be altered by the ecu? or am i just a loser again

Sorry mate but that sensor is only a "narrow" one.

It can only measure fuel when you are cruising. Once you start pumping the throttle it is ignored and the maps that Nissan wrote for the ECU are injecting the fuel.

Its called "closed loop" and "open loop"

[The Mafia]

after all of this shit though I am going to say that your problem will be the FPR, even though I do not support ATMO BOVs attached to a AFMeterd ECU.

The pressure shouldn't be jumping all over the place, and with all the cars that I have tuned, I have had nothing but trouble with SARD and malpassi.

I try to convince people to stick to the factory FPR right until its at its complete max, then look at a Nismo, or whole new fuel system.

The factory rail and FPR are heaps of head room for standard engines. I think you can push up to 350rwkw with the factory gear. And no standard RB25DET or RB26 will last that long on that kind of power, so you'll be forging your engine before needing a fuel upgrade. Or at least doing it at the same time.

Edited March 1, 2012 by The Mafia

[SargeRX8]

I don't understand how you people can deny what Mafia is saying... I was not agreeing with the hate against a BOV or that it is 99% of the time the cause of stalling issues but it sure does run the car out of its original spec and can cause problems. Ive got a wideband and when I was testing an atmo BOV just to make sure it worked before I sold it off, I fitted it on. It didn't stall but it did come close sometimes, and my wideband went all the way down to 10.0 which is the lowest(richest) reading it can display. Fuel cut really doesn't have much effect on this, Ive raised my fuel cut to some ridiculous amount when I disabled my BOV to try get around this stalling issue. Couldn't do it. Fuel cut is more there to stop fuel being used when you are cruising with your foot off the pedal in a gear. I can be in 4th gear at 6000rpm and lift my foot off the accelerator. My wideband will show --.- which is the leanest it can do and injector duty at 0% Once you hit the fuel cut setting on the ECU(on my power fc anyway which is 1100) the car will start using fuel again to maintain its idle even though your foot is off the petrol. The whole thing confuses me because I don't know much about it but from what I have seen, a blocked/vented BOV will run your car rich. Simple as that.

[The Mafia]

Thanks Sarge, appreciate your input.

My Wideband goes as low as 8, and I have seen down to 8.5 due to BOVs.

And because the map position is very erratic, its very hard to remove fuel from the right cells to stop stalling or issues.

And I will also agree - the decell is a real pain in the but to get right, and sometimes its not even worth touching.

[Bsa]

This is like year 5 show and tell dam funny I give up

[75coupe]

after all of this shit though I am going to say that your problem will be the FPR, even though I do not support ATMO BOVs attached to a AFMeterd ECU.

The pressure shouldn't be jumping all over the place, and with all the cars that I have tuned, I have had nothing but trouble with SARD and malpassi.

WTF!!! no it cant be true, dont even jest that it could none other that BOV causing all of his problems, it has to be the ATMO BOV it just has too...

and are you saying 80% of this thread was avoidable?

[mico]

my fuel pressure was a little jumpy, until i direct fed the fuel pump.

[Travis32]

today i removed the sard fpr and borrowed a wait for it lol malpassi off my mates car knowing it works.So i set base pressure at 45psi with out vacume.Attached vacume line and it the dropped to about 30psi.b4 i did this i did remove my blow off valve.As i rev'd the car i watched the pressure gauge and come to the conclusion that the sard reg = stuffed lol

so when the reving and returning to idle car did idle alot better it was still stalling but wasnt as bad as having the old reg on.So i thought i would try to up the base pressure to about 50psi to c if it would help.attached vac line etc gave it a rev and then it stalled completely lol.Stupid me has the evo sittin behind me car so had black shit all over the front bar lol.So i then put the bov back on and adjust fuel pressure back to 45psi base and it was the same as b4 i put it to 50psi

anyone make any sense of this.Keeping in mind b4 fitting fuel system bov had been on for like 4 yrs with out one stall so im at the end.

Can we removed iac valve without removing plenum?

[SargeRX8]

I read before you've got a forward facing. The stock one you can, no idea about aftermarket.

[Travis32]

I read before you've got a forward facing. The stock one you can, no idea about aftermarket.

sorry man its a stock gtr plenum on a gtr

[GTSBoy]

Find the hose that feeds the IAC and squirt some carby cleaner into it. Then reconnect the hose and run the car. Rince and repeat a few times. See if that cleans it out enough that your problem goes away or at least gets better. There really is no substitute for properly pulling them apart anc cleaning up with solvent + brushes, but you might be lucky.

[Travis32]

Find the hose that feeds the IAC and squirt some carby cleaner into it. Then reconnect the hose and run the car. Rince and repeat a few times. See if that cleans it out enough that your problem goes away or at least gets better. There really is no substitute for properly pulling them apart anc cleaning up with solvent + brushes, but you might be lucky.

sick thanks man could be blocked full of shit ay

[Don Dada]

You should also check your plugs as they may have gotten fouled from all that fuel dumped while testing