Sometimes leaning out @ WOT
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 762
Likes: 2
From: Kopavogur in Iceland
Sometimes leaning out @ WOT
hi
i'm trying to figure out a problem i have.....
sometimes when in WOT the Wideband shows all sudden lean after 4000 rpm's , i´m seeing all the way up to 15.5 AFR but the strange thing is that the car doesn't loose power or isn't even knocking, but offcourse i slow down right away, but then if i try it again, it's all right just on the spot 12.6 AFR, but sometimes it lean´s out twice in an row....
it never happens in daily driving if i go WOT it's seems to hold hand whith if make tune change's and FLASH (using (HPT) , , could be doing this first after i start the car up maby if i go WOT right away
the inj. readings are ok , the duty cycle is going up to 70% max around 60% often in WOT
Could my fuelpump be the reason, or maby one glogged injector, or maby the MAF is ****ing things up or the Wideband sensor/gauge giving fals signals
have anyone heard of this problem
My setup is C5 Vette 2003 402ci NA around 520 RWHP 500 RWTQ
stock fuel pump/rails
and the Bosch GT500 59lbs injectors
c5 z06 ported MAF
thanks
baezi
i'm trying to figure out a problem i have.....
sometimes when in WOT the Wideband shows all sudden lean after 4000 rpm's , i´m seeing all the way up to 15.5 AFR but the strange thing is that the car doesn't loose power or isn't even knocking, but offcourse i slow down right away, but then if i try it again, it's all right just on the spot 12.6 AFR, but sometimes it lean´s out twice in an row....
it never happens in daily driving if i go WOT it's seems to hold hand whith if make tune change's and FLASH (using (HPT) , , could be doing this first after i start the car up maby if i go WOT right away
the inj. readings are ok , the duty cycle is going up to 70% max around 60% often in WOT
Could my fuelpump be the reason, or maby one glogged injector, or maby the MAF is ****ing things up or the Wideband sensor/gauge giving fals signals
have anyone heard of this problem
My setup is C5 Vette 2003 402ci NA around 520 RWHP 500 RWTQ
stock fuel pump/rails
and the Bosch GT500 59lbs injectors
c5 z06 ported MAF
thanks
baezi
Tech Contributor
Joined: Jan 2007
Posts: 19,420
Likes: 1,146
From: Dyer, IN
hi
i'm trying to figure out a problem i have.....
sometimes when in WOT the Wideband shows all sudden lean after 4000 rpm's , i´m seeing all the way up to 15.5 AFR but the strange thing is that the car doesn't loose power or isn't even knocking, but offcourse i slow down right away, but then if i try it again, it's all right just on the spot 12.6 AFR, but sometimes it lean´s out twice in an row....
it never happens in daily driving if i go WOT it's seems to hold hand whith if make tune change's and FLASH (using (HPT) , , could be doing this first after i start the car up maby if i go WOT right away
the inj. readings are ok , the duty cycle is going up to 70% max around 60% often in WOT
Could my fuelpump be the reason, or maby one glogged injector, or maby the MAF is ****ing things up or the Wideband sensor/gauge giving fals signals
have anyone heard of this problem
My setup is C5 Vette 2003 402ci NA around 520 RWHP 500 RWTQ
stock fuel pump/rails
and the Bosch GT500 59lbs injectors
c5 z06 ported MAF
thanks
baezi
i'm trying to figure out a problem i have.....
sometimes when in WOT the Wideband shows all sudden lean after 4000 rpm's , i´m seeing all the way up to 15.5 AFR but the strange thing is that the car doesn't loose power or isn't even knocking, but offcourse i slow down right away, but then if i try it again, it's all right just on the spot 12.6 AFR, but sometimes it lean´s out twice in an row....
it never happens in daily driving if i go WOT it's seems to hold hand whith if make tune change's and FLASH (using (HPT) , , could be doing this first after i start the car up maby if i go WOT right away
the inj. readings are ok , the duty cycle is going up to 70% max around 60% often in WOT
Could my fuelpump be the reason, or maby one glogged injector, or maby the MAF is ****ing things up or the Wideband sensor/gauge giving fals signals
have anyone heard of this problem
My setup is C5 Vette 2003 402ci NA around 520 RWHP 500 RWTQ
stock fuel pump/rails
and the Bosch GT500 59lbs injectors
c5 z06 ported MAF
thanks
baezi
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
A misfire will show up lean. Are you logging your narrowbands too? You can't tune WOT with them, but they will respond to changes in oxygen/fuel at WOT. Look at the sensor 1 values in both banks and see what they're doing. WOT is very close to an open loop event unless your LTFT's are +, so WOT before your car gets to closed loop shouldn't be any different.
