loping idle

[gotsomegetsome]

Hey people, just trying to figure out whats goin on with my 7m and its strange idle lope / potential misfire

i dont have an oscilloscope so i cant see misfires perfectly but it sounds like there are a couple misfires here and there when I am idling
however, I have a vent 2 atm bov and when I was playing around, I opened up the BOV with my fingers and suddenly she idled perfectly

This leads me to think that my engine is running super lean? I cant really tell because I am still installing my innovate wideband, (which has taken a while because .. well other things) and I have no other way of telling

I do have an safc2 but everything is set to 0%. I checked for vacuum leaks but none as I can tell so far, perhaps I'll keep looking.

The only thing that was left open was the PCV air inlet on the throttle, but even when i plug it with my finger it doesnt change anything, at least much.


Ideals ppl? thanks

 

[gotsomegetsome]

:/?

 

[gotsomegetsome]

:/?

i have a mhg with arp head studs, 2.5" hardpipes all around
I tried to see if I had vacuum leaks and I have none
did the thing where i squeeze the iscv pipe and put my finger over the pcv valve so that I could check and yup the engine died

so no vacuum leaks for now. what else could be causing this idle crudd

 

[kotu100]

start the car and let it warm up, at idle what does the KAR reading say? does it bounce around a lot, or stay fairly steady? did you set up the safc settings correctly?

 

[boostin300]

Well if you're still using an AFM.. do NOT VENT TO FRIEKIN ATMOSPHERE. Seriously, no one friggin listens when people say this. The AFM measures the air and adjusts fuel accordingly. If you lose air or gain extra air (BOV open with vacuum) then your getting too much air and the fuel is not adjusted for the extra air because the ECU never measured it. If you don't think it's a problem, then have fun with constant misfires while your bov is open at vacuum.

Have you ever stalled inbetween a shift? That would also be the reason..

Just because it sounds cool when you shift doesnt mean you should.

The only time you should really vent to atmosphere is with a MAP sensor and VPC (speed density, NO AFM/MAF)

Just recirculate it AFTER the AFM and BEFORE the turbo and your problem will go away, guaranteed.

Edit: BTW, dont mess with the idle settings on the SAFC. Just leave it on the base setting until higher rpms

 

[kotu100]

Well if you're still using an AFM.. do NOT VENT TO FRIEKIN ATMOSPHERE. Seriously, no one friggin listens when people say this. The AFM measures the air and adjusts fuel accordingly. If you lose air or gain extra air (BOV open with vacuum) then your getting too much air and the fuel is not adjusted for the extra air because the ECU never measured it. If you don't think it's a problem, then have fun with constant misfires while your bov is open at vacuum.

Have you ever stalled inbetween a shift? That would also be the reason..

Just because it sounds cool when you shift doesnt mean you should.

The only time you should really vent to atmosphere is with a MAP sensor and VPC (speed density, NO AFM/MAF)

Just recirculate it AFTER the AFM and BEFORE the turbo and your problem will go away, guaranteed.

Edit: BTW, dont mess with the idle settings on the SAFC. Just leave it on the base setting until higher rpms

yea that would work, but what does a BOV venting to atmosphere have to do with a loping idle? at idle no air is coming out of the BOV, so the a/f ixture isnt getting messed with.

 

[boostin300]

Because dude, at vacuum (idle or decelerating) your BOV is OPEN (air goes into your engine through the BOV, like its a secondary intake). There's no air going out of it because its vacuum.. If its past the AFM, which yours is, your motor is sucking UNMETERED air through. This air goes into the combustion chamber with the improper amount of fuel and your ecu goes WTF IS GOING ON LOLO and tries to compensate through using TPS/Crank position inputs but sees the throttle is closed so it adjusts timing and whatever else to try and get a smooth idle. Humor me and put your hand over the opening of the BOV at idle and see what happens. No it wont suck your hand in lol.. Unless you have another problem or a vac leak somewhere it should work. Basically, using a BOV like you are is exactly like having a HUGE vacuum leak.

Seriously dude, just recirculate. So many noobs vent to atmosphere without a MAP sensor because it sounds cool and they just dont get it. Read this post and the one above until you understand what im saying. If you want to vent to atmos then buy a stupid VPC/MAP/IAT sensor and be done with it. Otherwise, recirculate it. End of story.

 

[thevork]

Because dude, at vacuum (idle or decelerating) your BOV is OPEN (air goes into your engine through the BOV, like its a secondary intake). There's no air going out of it because its vacuum.. If its past the AFM, which yours is, your motor is sucking UNMETERED air through. This air goes into the combustion chamber with the improper amount of fuel and your ecu goes WTF IS GOING ON LOLO and tries to compensate through using TPS/Crank position inputs but sees the throttle is closed so it adjusts timing and whatever else to try and get a smooth idle. Humor me and put your hand over the opening of the BOV at idle and see what happens. No it wont suck your hand in lol.. Unless you have another problem or a vac leak somewhere it should work. Basically, using a BOV like you are is exactly like having a HUGE vacuum leak.

Seriously dude, just recirculate. So many noobs vent to atmosphere without a MAP sensor because it sounds cool and they just dont get it. Read this post and the one above until you understand what im saying. If you want to vent to atmos then buy a stupid VPC/MAP/IAT sensor and be done with it. Otherwise, recirculate it. End of story.

I'm with kotu100.
You are not correct. I (as a lot of people) have an HKS SSQ bov and it is CLOSED under vacuum. A lot of other BOV's are too.
So stop saying that there is an air leak at the BOV because you can't know if that is true for sure

Furthermore, in the OP GSGS clearly states that the engine runs better with the bov opened up. That would mean that the car would idle even worse with a recirculated bov

But all that is beside the point. Of course the TS has to search for vacuum leaks.
Personally I think that the effect of opening the bov manually is that there is more unmetered air and for a few seconds the idle rpm rises until the ecu compensates and brings it back down.

Things to do:
Check for error codes as per tsrm.
Check for vacuum leaks. (Spray some carb cleaner near possible air leak places like couplers and your bov and see if the idle rpm goes up a little.)
Check to make sure the ICSV works by removing the plug to see if your idle changes. If it changes the icsv is probably working correct.
Check your Vf signal. Search the forum for more info on that as you can fill an entire topic just with how the Vf signal works

 

[IJ.]

Because dude, at vacuum (idle or decelerating) your BOV is OPEN (air goes into your engine through the BOV, like its a secondary intake). There's no air going out of it because its vacuum.. If its past the AFM, which yours is, your motor is sucking UNMETERED air through. This air goes into the combustion chamber with the improper amount of fuel and your ecu goes WTF IS GOING ON LOLO and tries to compensate through using TPS/Crank position inputs but sees the throttle is closed so it adjusts timing and whatever else to try and get a smooth idle. Humor me and put your hand over the opening of the BOV at idle and see what happens. No it wont suck your hand in lol.. Unless you have another problem or a vac leak somewhere it should work. Basically, using a BOV like you are is exactly like having a HUGE vacuum leak.

Seriously dude, just recirculate. So many noobs vent to atmosphere without a MAP sensor because it sounds cool and they just dont get it. Read this post and the one above until you understand what im saying. If you want to vent to atmos then buy a stupid VPC/MAP/IAT sensor and be done with it. Otherwise, recirculate it. End of story.

You're new here and all excited but here's a friendly word of advice....

STFU for awhile until you have all the details of an issue and then make an informed logical post.

 

[AndyMac]

IJ is correct.

and valves only open with positive pressure. Vac holds it closed.

 

[IJ.]

IJ is correct.

and valves only open with positive pressure. Vac holds it closed.

Other way around Andy
(if you mean on the signal line into the BoV)

 

[AndyMac]

Other way around Andy
(if you mean on the signal line into the BoV)

haha nah I meant the valve itself

 

[IJ.]

LOL they actually work on a pressure differential across both sides

 

[noel]

so no vac. leaks what about boost leaks? What shape are ur gaskets in? IF ALL OF THIS checked out then look at ur CPS WIREing..i had the same problem so i changed the O2 sensor and problem solved

 

[AndyMac]

LOL they actually work on a pressure differential across both sides

damn you for knowing everything!

it made perfect sense in my head

 

[boostin300]

Lol IJ .. Im not new on supraforums, thats for sure..

Anyway you do know what Im talking about with the unmetered air. I sound like a dick but a lot of people have issues and a lot of it does trace back to a BOV problem. Dude, with any problem there are seriously hundreds of things that could be causing it. I just posted up what I thought it could be and my own experiences with what happens with a non recircd BOV still running a MAF.

Good luck OP

 

[kotu100]

Lol IJ .. Im not new on supraforums, thats for sure..

Anyway you do know what Im talking about with the unmetered air. I sound like a dick but a lot of people have issues and a lot of it does trace back to a BOV problem. Dude, with any problem there are seriously hundreds of things that could be causing it. I just posted up what I thought it could be and my own experiences with what happens with a non recircd BOV still running a MAF.

Good luck OP

its a AFM

oh and OP you never answered my question.

 

[IJ.]

Lol IJ .. Im not new on supraforums, thats for sure..

Anyway you do know what Im talking about with the unmetered air. I sound like a dick but a lot of people have issues and a lot of it does trace back to a BOV problem. Dude, with any problem there are seriously hundreds of things that could be causing it. I just posted up what I thought it could be and my own experiences with what happens with a non recircd BOV still running a MAF.

Good luck OP

You're new here and quickly becoming a PITA with your posts in Tech, I don't really care who you are or how long you've been on other forums, take the time to post useful information in Tech threads or your stay here will be a short one.

Good rule of the thumb if you're not sure of your information fact check it or just STFU and don't post.

 

[boostin300]

You're new here and quickly becoming a PITA with your posts in Tech, I don't really care who you are or how long you've been on other forums, take the time to post useful information in Tech threads or your stay here will be a short one.

Good rule of the thumb if you're not sure of your information fact check it or just STFU and don't post.

Yep..

OP, I apologize. There could be a lot wrong or just one thing. My bad calling you a noob, but running an open vent BOV without speed density can potentially cause a problem and I think others can verify that. MAF v AFM .. I did have a MKII once with the flapper-type AFM. AFM + IAT = MAF, I understand that and used the wrong terminology.

Sorry for not answering your question, read your original post about opening the BOV at idle and that fixing the problem, first thing that came to mind was the vent to atmo and running an AFM. It could be that you need a lighter spring, as the BOV should open at idle under vacuum. Spring doesn't matter once you're into boost as it'll close anyway.

I apologize, I come from supraforums where everyone acts like a dick lmao.

Good luck sir.

 

[IJ.]

Yep..

OP, I apologize. There could be a lot wrong or just one thing. My bad calling you a noob, but running an open vent BOV without speed density can potentially cause a problem and I think others can verify that. MAF v AFM .. I did have a MKII once with the flapper-type AFM. AFM + IAT = MAF, I understand that and used the wrong terminology.

Sorry for not answering your question, read your original post about opening the BOV at idle and that fixing the problem, first thing that came to mind was the vent to atmo and running an AFM. It could be that you need a lighter spring, as the BOV should open at idle under vacuum. Spring doesn't matter once you're into boost as it'll close anyway.

I apologize, I come from supraforums where everyone acts like a dick lmao.

Good luck sir.

Think carefully about this for a few minutes....