newby ltrim help
Thread Starter
TECH Junkie
iTrader: (71)
Joined: Mar 2002
Posts: 3,703
Likes: 0
From: East Brady, Pa
newby ltrim help I just got atap and maft and I'm learning so bear with me. At base settings my idle ltrims are +2 and wot ltrims were +9 to +11. Now after 10% rich maft setting my idles are -3 and wot are still from +7 to +9. Basically I just drive around and watch what the ltrims do. The higher the throttle percentage the leaner I go. It seems like I've made progress. I just want to make sure I'm doing the right thing so far before I go any further. I haven't gotten into averaging everything out yet. Just cruising at 15% to 20% throttle my ltrims are usually around +2. thanks in advance.
Staging Lane
Joined: Feb 2002
Posts: 97
Likes: 0
From: Newport, Michigan
Re: newby ltrim help Set the base setting on the MAFT to 10% rich and the WOT setting to no change. Do a PCM reset, then drive the car around and see what happens to the Lterm fuel trims. They should be close to 0% or slightly negative.
TECH Apprentice
Joined: Jan 2002
Posts: 364
Likes: 0
From: Princeton, IN
Re: newby ltrim help i would say you have a vacume leak, your ltrims should go down when you give it gas. at idle my ltrims run around .0 to -.8. at about 2000 rpm;s on the highway they run about 4 to 6% if i give it some gas they go to more like 2 or close to 0% when i had a vacume leak around my egr the ltrims would raise to 15%+ at idle if i hit the gas they also would go up very quickly, sometimes even to 25%. look for leaks after the maf, a few times i forgot to srew down the hose that goes around my TB.
