ltrims=25%
TECH Apprentice
Joined: Jan 2002
Posts: 364
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From: Princeton, IN
Re: ltrims=25% Do you have ported maf ends? Are your ltrims +25% at idle? You should be getting a SES for lean if you are running 25% or more.
Could be a vacuum leak...
"post back with more info"
Could be a vacuum leak...
"post back with more info"
Re: ltrims=25% And Drive' went 11.62@116mph so the car is doing pretty good.
Looks like you are very rich but what I'd do is borrow a MAF T and track test it.... run stock.... change the WOT... drive the car a bit, and come back...
Anything in the 7-10% is fine.
Looks like you are very rich but what I'd do is borrow a MAF T and track test it.... run stock.... change the WOT... drive the car a bit, and come back...
Anything in the 7-10% is fine.
Thread Starter
TECH Junkie
Joined: Nov 2001
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From: Chi-Town
Re: ltrims=25% perhaps i was looking at the wrong fields? i found three different ltrims. one was at 16%, the other 2 were at 25%. the strims were around -1 thru +1 at idle.
car likes to surge when i let off the gas quickly which leads me to believe its dumping too much fuel in.
i am borrowing dann00hawks maft john.
car likes to surge when i let off the gas quickly which leads me to believe its dumping too much fuel in.
i am borrowing dann00hawks maft john.
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TECH Apprentice
Joined: Jan 2002
Posts: 364
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From: Princeton, IN
Re: ltrims=25% You should find 2 ltrims "bank1, bank2" 2 strims "bank1, bank2"
I don’t know if everyone will agree with me but your ltrims should be around 0% at idle - I would say negative decimals are safer “pinging, burning valves/pistons
With my 85mm maf I run at 0% to -1 or -2%, at part throttle I run way to lean with it. Stock maf with a screen is dead on most of the time.
You might run a little rich at WOT and have a vacuum leak, my egr had a small leak around the pipe that runs in to the intake. I could hear the leak but I had a hard time finding it. Rev the engine and watch the ltrims, if the number shoots up to like +15% or more then come back down I would say you have a vacuum leak.
While the engine is running take a cigarette and move it around the vacuum lines, or any place that is behind the maf. If you see the smoke being pulled, then you know you have a leak in that area. Crab cleaner does the same things, when you spray it around the leak the motor will raise the idle a little.
<small>[ August 23, 2002, 08:51 AM: Message edited by: dissonance ]</small>
I don’t know if everyone will agree with me but your ltrims should be around 0% at idle - I would say negative decimals are safer “pinging, burning valves/pistons
With my 85mm maf I run at 0% to -1 or -2%, at part throttle I run way to lean with it. Stock maf with a screen is dead on most of the time.
You might run a little rich at WOT and have a vacuum leak, my egr had a small leak around the pipe that runs in to the intake. I could hear the leak but I had a hard time finding it. Rev the engine and watch the ltrims, if the number shoots up to like +15% or more then come back down I would say you have a vacuum leak.
While the engine is running take a cigarette and move it around the vacuum lines, or any place that is behind the maf. If you see the smoke being pulled, then you know you have a leak in that area. Crab cleaner does the same things, when you spray it around the leak the motor will raise the idle a little.
<small>[ August 23, 2002, 08:51 AM: Message edited by: dissonance ]</small>
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Verdad Gallardo TECH Apprentice
Joined: Jan 2002
Posts: 364
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From: Princeton, IN
Re: ltrims=25% Sorry guys I hit refresh on my post screen and reposted what I posted the 1st time <img border="0" title="" alt="[Embarrassed]" src="gr_emb.gif" />
Try lessening for a hissing sound from the breather area
<small>[ August 23, 2002, 08:55 AM: Message edited by: dissonance ]</small>
Try lessening for a hissing sound from the breather area
<small>[ August 23, 2002, 08:55 AM: Message edited by: dissonance ]</small>
TECH Senior Member
Joined: Nov 2001
Posts: 10,341
Likes: 1
Re: ltrims=25% I think you may have a vac leak somewhere. Are you runing an LS6 or Ls1 intake manifold?
EGR and PCV are the usual major sources of vac leaks. Check seal between MAF and T-body.
Cheers,
Chris
ps- you will pick up a lot more when you fix the problem.
EGR and PCV are the usual major sources of vac leaks. Check seal between MAF and T-body.
Cheers,
Chris
ps- you will pick up a lot more when you fix the problem.
TECH Apprentice
Joined: Jan 2002
Posts: 364
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From: Princeton, IN
Re: ltrims=25% I had a problem like yours ltrims maxed out lean. It was the seal around my egr. If you have ever removed it you might have bent the pipe to much and it does not seal. That’s what happened to mine. Then I tried fixing it and just could not get it to seal.
Ended up buying a new one from gm. it was only $98
What year is your car?
Ended up buying a new one from gm. it was only $98
What year is your car?
Thread Starter
TECH Junkie
Joined: Nov 2001
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From: Chi-Town
Re: ltrims=25% its a 2001, no egr. the ONLY problem i have is starting the car. when starting the car after its been running, it wont fire right up (after the cam install). i have to give it some gas. sometimes it dies when i let off too quickly at a stoplight. it idles near perfect though.
Thread Starter
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From: Chi-Town
Re: ltrims=25% update:
i ran the ltrims again. i found a total of FOUR different ones. i used the B1 and B2, one was at 0 the whole time, and the ohter was just an extra B1. at idle it was at 25%. i would rev it up and it would drop to about 17% at 2400 rpms. let off and it floated around a little before stopping at 25%. i plugged the maft in and played with the settings. nothing made a difference at idle- 850ish-900. Sometimes i would blip the throttle and let off and it would hover around 22-23% on some of the settings. at part throttle the numbers would go DOWN as i made it richer, and go up as i made it leaner. the fans were on so i couldnt test the smoke.
2%leaner means it will make the car 2% leaner, right. just so i know im not an idiot and doing it wrong.
i ran the ltrims again. i found a total of FOUR different ones. i used the B1 and B2, one was at 0 the whole time, and the ohter was just an extra B1. at idle it was at 25%. i would rev it up and it would drop to about 17% at 2400 rpms. let off and it floated around a little before stopping at 25%. i plugged the maft in and played with the settings. nothing made a difference at idle- 850ish-900. Sometimes i would blip the throttle and let off and it would hover around 22-23% on some of the settings. at part throttle the numbers would go DOWN as i made it richer, and go up as i made it leaner. the fans were on so i couldnt test the smoke.
2%leaner means it will make the car 2% leaner, right. just so i know im not an idiot and doing it wrong.
Thread Starter
TECH Junkie
Joined: Nov 2001
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From: Chi-Town
Re: ltrims=25% i did the smoke thing and didnt really see it suckin in anywhere. i looked in the back and the pcv vavle was sticking out a little on the driverside. pushed it in and wamo. ltrims went to 18% driverside and 16.5% pas. side <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Thread Starter
TECH Junkie
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From: Chi-Town
Re: ltrims=25% even more wierd- i unplugged the MAFT (even after having it set to 0 and 0) and it dropped to 15.6 on each side <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> . the maft seemed to make things worse <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> and no it wasnt the maft the whole time cause i tested before i plugged it in too. could just be in my mind but it seems to idle better when coming to lights. cant tell if theres more power or not...
TECH Apprentice
Joined: Jan 2002
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From: Princeton, IN
Re: ltrims=25% Great! So your ltrims are at about 15 when idling? I have forgotten to tighten the tube that runs from the maf to the throttle body before. If you have any air coming in after the maf it will show lean.
Make sure you have the LONG TRIMS bank1, bank2 NOT THE SHORT TRIMS
Turn your BASE and WOT to 0%
You might want to try to reset the pcm before you do this. if you do reset; drive the car around for 30 min's or so.
Start the car and let it warm up. It should only take a min or two for the o2 sensors to start reading lean/rich.
Once your ready turn the base to 5% rich if your ltrims are +. 5% lean if your ltims are rich. Positive numbers are lean/ negative numbers are rich
Once you have made the adjustment the ltrim should have gone down some “2%-4%.
Repeat this until you get your ltrims around 0% to -2%
I would replace your ported ends with the stock ends and screen. I talked to a guy making over 400rwhp with the stock maf ends/screens
Once you feel that you have got the LTRIMS down. You should end up with no more then 15% rich. If you have to add more then 15% you are most likely still pulling unmetered air in.
Don’t worry about your WOT o2 reading yet, get everything lined out before you start moving up
Here is a great link on this subject
http://www.ls1info.com/article.php?sid=163
<small>[ August 23, 2002, 10:46 PM: Message edited by: dissonance ]</small>
Make sure you have the LONG TRIMS bank1, bank2 NOT THE SHORT TRIMS
Turn your BASE and WOT to 0%
You might want to try to reset the pcm before you do this. if you do reset; drive the car around for 30 min's or so.
Start the car and let it warm up. It should only take a min or two for the o2 sensors to start reading lean/rich.
Once your ready turn the base to 5% rich if your ltrims are +. 5% lean if your ltims are rich. Positive numbers are lean/ negative numbers are rich
Once you have made the adjustment the ltrim should have gone down some “2%-4%.
Repeat this until you get your ltrims around 0% to -2%
I would replace your ported ends with the stock ends and screen. I talked to a guy making over 400rwhp with the stock maf ends/screens
Once you feel that you have got the LTRIMS down. You should end up with no more then 15% rich. If you have to add more then 15% you are most likely still pulling unmetered air in.
Don’t worry about your WOT o2 reading yet, get everything lined out before you start moving up
Here is a great link on this subject
http://www.ls1info.com/article.php?sid=163
<small>[ August 23, 2002, 10:46 PM: Message edited by: dissonance ]</small>