LTFT's...
LTFT's... This has probably been asked many times before, I did a search on it, but can't find a solid answer. After my cam swap, I've taken some atap readings and my LTFT's are always about -14% at idle. Does this mean I'm running rich or lean? I don't know whether to lean out my car or richen it up. Please help. I'm going to get my car professionally tuned in the near future, but I want to make sure not to fugg anything up because I'm running too lean or rich in the mean time.
On The Tree
Joined: Mar 2002
Posts: 147
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From: South Florida
Re: LTFT's... LTFT's don't really mean that much at idle as long as it falls within the + or - 25. It's at cruise where it comes into play, you want them as close to 0 as possible, with most people wanting them on the slightly negative side. When on the negative side at cruise no fuel is added when you go wot, because ltft's will go to zero. Hope this helps.
TECH Addict
Joined: Jul 2002
Posts: 2,261
Likes: 0
Re: LTFT's...
LTFT's don't really mean that much at idle as long as it falls within the + or - 25. It's at cruise where it comes into play, you want them as close to 0 as possible, with most people wanting them on the slightly negative side. When on the negative side at cruise no fuel is added when you go wot, because ltft's will go to zero. Hope this helps.
Yep,to what Mike said. Remember, the PCM is adjusting to maintain stoich AFR (in closed loop)= 14.7. Therefore you are running niether lean or rich....you're running "Stoich".FWIW.
joel
