Lean under boost???
#1
Lean under boost???
Ok so ill start with my car. Its a 2003 VIII36k miles. My mods are as follows.
Injen upper and lower IC pipes
Injen Custom Intake W\ cone filter
HKS SSQ (vented no recirc yet)
Megan turbo back with cat delete
MBC at ~20PSI
SAFCII street tuned (by me AFR 11.3-11.6)
AEM UEGO wideband
so The last few days I noticed on cold start the car hardly idles when it does its at about 500 revs the wideband reads --- which is max lean, as soon as the car warms the revs go up to 2k then down to normal idle then the car runs fine. normal driveing everything feels and looks normal but as soon as I boost the car felt held back (this was 4th gear). When I looked at my AFR is was 13.3 so I paniched and backed out of the boost. So I go down a gear and go half throttle as soon as boost started the AFR went to about 15ish and it normally is at 12ish or high 11 around this point. So now I am confused I am guessing I have a fuel pump faliure under load, I am on the stock pump.
So any thoughts? is it a good assumption to look towards the pump at this point?? Thanks -Mike
Injen upper and lower IC pipes
Injen Custom Intake W\ cone filter
HKS SSQ (vented no recirc yet)
Megan turbo back with cat delete
MBC at ~20PSI
SAFCII street tuned (by me AFR 11.3-11.6)
AEM UEGO wideband
so The last few days I noticed on cold start the car hardly idles when it does its at about 500 revs the wideband reads --- which is max lean, as soon as the car warms the revs go up to 2k then down to normal idle then the car runs fine. normal driveing everything feels and looks normal but as soon as I boost the car felt held back (this was 4th gear). When I looked at my AFR is was 13.3 so I paniched and backed out of the boost. So I go down a gear and go half throttle as soon as boost started the AFR went to about 15ish and it normally is at 12ish or high 11 around this point. So now I am confused I am guessing I have a fuel pump faliure under load, I am on the stock pump.
So any thoughts? is it a good assumption to look towards the pump at this point?? Thanks -Mike
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Originally Posted by EMonz57
Ok so ill start with my car. Its a 2003 VIII36k miles. My mods are as follows.
Injen upper and lower IC pipes
Injen Custom Intake W\ cone filter
HKS SSQ (vented no recirc yet)
Megan turbo back with cat delete
MBC at ~20PSI
SAFCII street tuned (by me AFR 11.3-11.6)
AEM UEGO wideband
so The last few days I noticed on cold start the car hardly idles when it does its at about 500 revs the wideband reads --- which is max lean, as soon as the car warms the revs go up to 2k then down to normal idle then the car runs fine. normal driveing everything feels and looks normal but as soon as I boost the car felt held back (this was 4th gear). When I looked at my AFR is was 13.3 so I paniched and backed out of the boost. So I go down a gear and go half throttle as soon as boost started the AFR went to about 15ish and it normally is at 12ish or high 11 around this point. So now I am confused I am guessing I have a fuel pump faliure under load, I am on the stock pump.
So any thoughts? is it a good assumption to look towards the pump at this point?? Thanks -Mike
Injen upper and lower IC pipes
Injen Custom Intake W\ cone filter
HKS SSQ (vented no recirc yet)
Megan turbo back with cat delete
MBC at ~20PSI
SAFCII street tuned (by me AFR 11.3-11.6)
AEM UEGO wideband
so The last few days I noticed on cold start the car hardly idles when it does its at about 500 revs the wideband reads --- which is max lean, as soon as the car warms the revs go up to 2k then down to normal idle then the car runs fine. normal driveing everything feels and looks normal but as soon as I boost the car felt held back (this was 4th gear). When I looked at my AFR is was 13.3 so I paniched and backed out of the boost. So I go down a gear and go half throttle as soon as boost started the AFR went to about 15ish and it normally is at 12ish or high 11 around this point. So now I am confused I am guessing I have a fuel pump faliure under load, I am on the stock pump.
So any thoughts? is it a good assumption to look towards the pump at this point?? Thanks -Mike
First of all wrong forum.
Second DO NOT VTA without a standalone.
Third that is definitely too lean for your car. I would shoot for 11.0 in the HOT summer days here in FLorida. In the winter you can shoot for the 11.6 AFR IMO...
#4
Originally Posted by VTECH8TR
Mike,
First of all wrong forum.
Second DO NOT VTA without a standalone.
Third that is definitely too lean for your car. I would shoot for 11.0 in the HOT summer days here in FLorida. In the winter you can shoot for the 11.6 AFR IMO...
First of all wrong forum.
Second DO NOT VTA without a standalone.
Third that is definitely too lean for your car. I would shoot for 11.0 in the HOT summer days here in FLorida. In the winter you can shoot for the 11.6 AFR IMO...
2) I am waiting on my recirc kit ( I dont plan to stay that way TRUST MEE lol)
3) I know it is way to lean but I am not in FL any more either and yes I am normally around 11.3 AFR all time
#5
Originally Posted by AltezzaBob
is it knocking/detontaing and feeling sluggish when it runs lean?
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Originally Posted by EMonz57
I dont stay on it long enough to see. the one time when I noticed it ya it felt slow but I was only at about 4k rpms and just hit the gas then let off almost instantly cause I saw the AF stay lean
![Wink](https://www.evolutionm.net/forums/images/smilies/wink.gif)
#7
Originally Posted by VTECH8TR
I was gonna ask you to swing by as i live in Land O Lakes, but your not here. I would dial the boost down to 18 psi until you get the recirc kit, that should also make the car run a tad richer. Without it your car is running rich between shhifts which is not a good thing, but at least you are killing the mosquitoes
.
![Wink](https://www.evolutionm.net/forums/images/smilies/wink.gif)
But back to my AFR do you think I am looking at a pump faliure or something further?
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Originally Posted by EMonz57
Well I am rich bettween shifts but I am slightly tuned on the SAFC the best I could for it, the car doesnt stumble any longer on shifts but like I said not going to keep it vented for longer than I have too.
But back to my AFR do you think I am looking at a pump faliure or something further?
But back to my AFR do you think I am looking at a pump faliure or something further?
![Wink](https://www.evolutionm.net/forums/images/smilies/wink.gif)
It could be a # of things. It could be the fuel pump or a boost leak. Perform a leak boost on the car to see if you have any leaks. It is very easy to make one. Have you looked at the car over yet? Loose clamps etc....
#9
Originally Posted by VTECH8TR
I am just kidding on the VTA BOV
. Its your car and your choice.
It could be a # of things. It could be the fuel pump or a boost leak. Perform a leak boost on the car to see if you have any leaks. It is very easy to make one. Have you looked at the car over yet? Loose clamps etc....
![Wink](https://www.evolutionm.net/forums/images/smilies/wink.gif)
It could be a # of things. It could be the fuel pump or a boost leak. Perform a leak boost on the car to see if you have any leaks. It is very easy to make one. Have you looked at the car over yet? Loose clamps etc....
as for the BOV it drives me insane being loud anyways but I make do with what I got for now.
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Yes thats very lean indeed. But i run leaner than that daily. 12.1-11.9 granted im on 100 though. Check all your SAFC settings and intercooler pipes. But i think that if u had a boost leak u would run rich. Maybe a fuel press. problem?
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I have allmost the exact same problem.. I'm recirced with a forge DV. .. here is my on-going thread https://www.evolutionm.net/forums/ev...isengaged.html
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