Can't lean out far enough at idle
Thread Starter
Teching In
Joined: Dec 2001
Posts: 47
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From: Tarpon Springs FL
Can't lean out far enough at idle I have a 2000 heads/cam(216/220)/intake(LS6)car which I recently added the SVO 30 lb injectors. The 26 lbers were too lean at WOT. My PCM was reprogrammed by Ed Wright when the heads/cam intake was done. My problem is I cannot lean it out at idle. I have a translator and initially started at -10% base. The LTFT's were -10% for both banks. I then went to -15% reset the PCM and its still at -10% LTFT and smells terribly rich at idle. Could it be Ed's programming took into account the 00's puny injectors and set a fuel curve too fat for me to overcome now?
Thread Starter
Teching In
Joined: Dec 2001
Posts: 47
Likes: 0
From: Tarpon Springs FL
Re: Can't lean out far enough at idle At idle the average bank pulse width is 2.65ms. I did wait a while after the base chnges were made. It has been over 100 miles and three days of driving. The base setting change from -10% to -15% did not effect the richness.
On The Tree
Joined: Jan 2002
Posts: 120
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From: Aloha, Oregon
Re: Can't lean out far enough at idle first off, are you allowing enough time for the MAF T adjustments to trim out? by their very nature, LTFT's take 30+ minimum miles of varying conditions to update from MAFT changes on Base. there is no getting around this. the longer you drive, the more they will dampen out. only the WOT adjustment on the MAFT will yield instantaneous change. i have found with my C5 it takes about 100 miles to really tell the true results of my Base adjustments on MAFT.
tell me, what data led you to believe the stock injectors were too small for your mods? how was the Injector Pulse Width ave at WOT on each bank? regardless of any prior PCM tuning, you should be able to efficate changes with your MAFT. what is your IPW ave at idle?
[ January 07, 2002: Message edited by: nitrousc5 ]</p>
tell me, what data led you to believe the stock injectors were too small for your mods? how was the Injector Pulse Width ave at WOT on each bank? regardless of any prior PCM tuning, you should be able to efficate changes with your MAFT. what is your IPW ave at idle?
[ January 07, 2002: Message edited by: nitrousc5 ]</p>
Re: Can't lean out far enough at idle I put a bigger intank into my car and now I have to use the MAF T to adjust my BASE fuel...
I have it at -15%.
IMO, I see the Ltrims start changing within a minute.
IMO, I would balance what you see with what works for the car.
My car was surging like crazy. It was loading up at lights and almost dying out.
I'm going to leave it like this until I can dyno with a wideband or hit a track.
Then I may tweak the programming if it makes sense.
I have it at -15%.
IMO, I see the Ltrims start changing within a minute.
IMO, I would balance what you see with what works for the car.
My car was surging like crazy. It was loading up at lights and almost dying out.
I'm going to leave it like this until I can dyno with a wideband or hit a track.
Then I may tweak the programming if it makes sense.
