LTFT on start up +11, then go to -1? how to fix
07-29-2005, 09:48 PM
#1
LTFT on start up +11, then go to -1? how to fix on start up my trims at +11 and +8, then after the car is warmed up, ill have to look at the logs to see if its at a consistent temp, the trims go down to -1 or -2, how in the world can i get the numbers on start up to get lower? i think this might have to do with my problem of + trims at the drag strip.
07-29-2005, 11:08 PM
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I have to think that this is all about your O2 sensors,
mistrimming to a false lean reading and getting more
accurate after being hot a while.
When you look at the O2s at startup and at shutdown
do you see qualitative differences?
mistrimming to a false lean reading and getting more
accurate after being hot a while.
When you look at the O2s at startup and at shutdown
do you see qualitative differences?
07-30-2005, 06:06 AM
#6
i have no emissions stuff on the car so its not the air pump.
jimmy, ive got the o2s working a lot better now, at least i think. if you pm me your email and dont mind taking a look, i can send you my log file. my o2s move around a good bit at idle, and they are getting a lot better, i dont knowif they need to be "borken in" or what but i have seen them get better and i have also tried proportional fuel changes, that have helped. shoot me a pm iwht your email if you dont mind.
i can send you the log from the drag run as well, the first and only run the trims locked + because before the run they were +, and im wondering if it stays like that until i reset them. just let me know, id like to get this taken care of asap, thanks.
jimmy, ive got the o2s working a lot better now, at least i think. if you pm me your email and dont mind taking a look, i can send you my log file. my o2s move around a good bit at idle, and they are getting a lot better, i dont knowif they need to be "borken in" or what but i have seen them get better and i have also tried proportional fuel changes, that have helped. shoot me a pm iwht your email if you dont mind.
i can send you the log from the drag run as well, the first and only run the trims locked + because before the run they were +, and im wondering if it stays like that until i reset them. just let me know, id like to get this taken care of asap, thanks.
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07-30-2005, 06:58 AM
#8
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Originally Posted by ChrisLe
Air Pump maybe?
Originally Posted by WS6FirebirdTA00
i have no emissions stuff on the car so its not the air pump.
07-30-2005, 12:58 PM
#11
here are some screen shots, the first one is the only one that seems to be screwy, but why would after a start up that kinda stuff happen. i shut the car off and put in another tune and it didnt do that. that log started at soon as i started the car. and hte other ones with just 2 graphs are at idle where my trims change, 2 min 38 sec consistently.
07-30-2005, 03:14 PM
#14
no i end up in ftc 19, not sure on start up ill check next time though. i reset the fuel trims and i didnt have that change over at 2 min 38 sec this time. seems to be running better to. o2 sensors might have just had to be used a little while before they got broek in cause now they are moving at a good clip. any other ideas on what to check or anything though let me know, ill see how this latest tune does, hopefully its just stored ltft numbers that were false
07-30-2005, 04:02 PM
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Originally Posted by jimmyblue
I have to think that this is all about your O2 sensors,
mistrimming to a false lean reading and getting more
accurate after being hot a while.
When you look at the O2s at startup and at shutdown
do you see qualitative differences?
mistrimming to a false lean reading and getting more
accurate after being hot a while.
When you look at the O2s at startup and at shutdown
do you see qualitative differences?
firebird:I bet you will see lean readings whenever you let off the throttle abruptly after a wot run. The only area Im really worried about are when the tps isnt 0. If im saving fuel at idle thats fine with me.
Last edited by 02sierraz71_5.3; 07-30-2005 at 04:08 PM.
07-30-2005, 04:20 PM
#16
actually no, after a wot run, 0 throttle and gettin on the brakes, the o2s go a little low then back up then low and continue the fast oscillation. i really think my o2s needed more time in the car, i have done nothing the last few logs to get them better and they are oscillation 5 times more than they did at first when jimmy commented on the problem in another post. i think and hope the fuel trims not being reset caused this. from waht i can tell now, the car is a lot better, we will find out after some time though. i would still like to know why this happened?
07-30-2005, 06:06 PM
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not trying to post ***** but I think my situation is similar after wot I get really lean ltft's, the st are 0 and the actual afr reading doesnt relate a lean condition
I am running a maf the only explanation I can think of is that at the maf hz I see around 3500 at idle and also right after I let off the throttle I see similar maf hz, my ve table was tuned in sd.
below is a pic
I am running a maf the only explanation I can think of is that at the maf hz I see around 3500 at idle and also right after I let off the throttle I see similar maf hz, my ve table was tuned in sd.
below is a pic
07-30-2005, 07:33 PM
#18
get your own damn post! haha jk 
how new are your o2s? ive adjusted my proportional fueling and that seems to help a good bit. dips in o2s could also be from lean spots in the ve if im correct. either way this was killing me at the track. i really hope its just learned fuel trims that were screwing with me in open loop and they stuck until the car got warm. none of my other runs showed this before WOT. ill find out this thurs, maybe i can hit the 7's lol car felt like it lost 40 hp from the street to the strip being so damn rich
how new are your o2s? ive adjusted my proportional fueling and that seems to help a good bit. dips in o2s could also be from lean spots in the ve if im correct. either way this was killing me at the track. i really hope its just learned fuel trims that were screwing with me in open loop and they stuck until the car got warm. none of my other runs showed this before WOT. ill find out this thurs, maybe i can hit the 7's lol car felt like it lost 40 hp from the street to the strip being so damn rich
07-30-2005, 09:14 PM
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Originally Posted by WS6FirebirdTA00
get your own damn post! haha jk how new are your o2s? ive adjusted my proportional fueling and that seems to help a good bit. dips in o2s could also be from lean spots in the ve if im correct. either way this was killing me at the track. i really hope its just learned fuel trims that were screwing with me in open loop and they stuck until the car got warm. none of my other runs showed this before WOT. ill find out this thurs, maybe i can hit the 7's lol car felt like it lost 40 hp from the street to the strip being so damn rich
how new are your o2s? ive adjusted my proportional fueling and that seems to help a good bit. dips in o2s could also be from lean spots in the ve if im correct. either way this was killing me at the track. i really hope its just learned fuel trims that were screwing with me in open loop and they stuck until the car got warm. none of my other runs showed this before WOT. ill find out this thurs, maybe i can hit the 7's lol car felt like it lost 40 hp from the street to the strip being so damn richDont know if you got a chance to look at my crazy *** log but the more I think about it the more I think its my ve table is ascue in that area. After 2 months of messing with it I got it back back smooth I mean butter now Ive got to mess with it again.