My LT1 is running lean
Thread Starter
Teching In
Joined: Mar 2009
Posts: 19
Likes: 0
From: Belton, TX
My LT1 is running lean I just recently noticed that my TA is running lean. everything from the pump to the injectors has been replaced. Pressure tested out ok at 38psi at idle. Just need some suggestions on what else to look at for a lean mixture other than the obvious fuel system. I was thinking the MAP sensor, but no SES light is on. wasnt sure if there was a situation where the MAP wouldnt throw a code. gracias
TECH Fanatic
Joined: Jan 2005
Posts: 1,162
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From: St. Augustine, FL
Need more info. Has it been good for a while and now suddenly went to hell or is this like an initial thing and your chasing down the problem? Are you confident its tuned good? What is leading you to believe its running lean (wideband A/F readings or you just checking the plugs)?How lean are you talking and at what RPM? 14:1, 15:1, higher? Sure your O2's are good?
Thread Starter
Teching In
Joined: Mar 2009
Posts: 19
Likes: 0
From: Belton, TX
Its been acting up for a while now. It stutters with about 5 seconds of constant highway speed (60ish), Ill let off and it runs fine for another 5 secs and does this over and over again. Changed the plugs, which is when i found the plugs looked like it had been running lean. I would say it is around the 15:1 range if i had to guess. Had it tuned by a pretty reputable tuner around the area, so not too worried about that.
Thread Starter
Teching In
Joined: Mar 2009
Posts: 19
Likes: 0
From: Belton, TX
yup, that among other things is why I had to get the tune. I was expecting it to get fixed with the tune. Before the tune it had the stock MAF sensor still on it, so I'm a little confused.
You need to pinpoint your problem. "Seeming" to have a lean condition because the plugs "looked like it" and making up an arbitrary a/f ratio won't get you anywhere. For all you know, it could be something much simpler.
Get it on a scanner and monitor your O2s (among other things) if you suspect it running lean.
Get it on a scanner and monitor your O2s (among other things) if you suspect it running lean.
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Teching In
Joined: Feb 2023
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Running lean lt1 with 24x Hello everyone
I have camaro 1995 and the car running lean and rich but must of the time lean I have widband and im at 15.7afr and even when I try to add fuel still not adding I check my fuel pump and fuel filter and the injector all good and new I check the manifold no leak and the hoses all good I don’t know what is the problem must of the time lean sometimes go to rich then go back to lean the car has no EGR no O2 im thinking maybe some heads valve are leaking but im not sure if the valve not close enough will cause a lean afr
I have camaro 1995 and the car running lean and rich but must of the time lean I have widband and im at 15.7afr and even when I try to add fuel still not adding I check my fuel pump and fuel filter and the injector all good and new I check the manifold no leak and the hoses all good I don’t know what is the problem must of the time lean sometimes go to rich then go back to lean the car has no EGR no O2 im thinking maybe some heads valve are leaking but im not sure if the valve not close enough will cause a lean afr
