What trim cell should I be in WOT??
#1
What trim cell should I be in WOT??
Sounds like a dumb Q, but I should be in cell 15 at WOT, right?. I somehow thought it was cell 18 that it should be in. BTW, Im trying to adjust my tune. I am running BLM 145-147 at WOT but everything else is slightly rich at 117-122 BLM. As soon as it enters cell 15, the BLMs go way to the 140s. Any thoughts or remedys?
Last edited by MTBeni; 10-21-2006 at 09:11 AM.
#2
Re: What trim cell should I be in WOT??
Which cell it runs in at WOT varies between 15 and 18. If the PCM is adding fuel in cell 15, it will use cell 15 in PE mode. If the PCM was cutting fuel in the upper load range cells, it seems to do one of two things.... 1) use cell 15 but lock the BLM's at 128 or 2) default to Cell 18 and lock the BLM's at 128. Not clear to me how it decides between 1) and 2) (might be related to whether its running EVAP in PE mode???).
If you are in cell 15 and seeing 140+ BLM's, its because that's what the PCM "learned" running in closed loop. It would be very unusual for all the cells other than cell 15 to be cutting fuel (117-122 BLM's) and then suddenly see cell 15 with 140+ BLM's. That could indicate the MAF sensor calibration is way off, under reporting mass air flow at high flow.
Do you have a data log that we can look at?
If you are in cell 15 and seeing 140+ BLM's, its because that's what the PCM "learned" running in closed loop. It would be very unusual for all the cells other than cell 15 to be cutting fuel (117-122 BLM's) and then suddenly see cell 15 with 140+ BLM's. That could indicate the MAF sensor calibration is way off, under reporting mass air flow at high flow.
Do you have a data log that we can look at?
#3
Re: What trim cell should I be in WOT??
I've even seen, on a datalog of an acceleration run I made, the PCM use cell 15 at WOT in 1st gear, then go to cell 18 at WOT in 2nd and 3rd, then back to cell 15 at WOT in 4th... all in the same run.
#4
Re: What trim cell should I be in WOT??
Thanks for the info guys. I have to go out of town for a few weeks tommorow, but I will pick this up when I get back. I'm off to SERE school (if you saw GI Jane, you'd have a good idea). Joys of my job you could say. BTW, what format would you like a log? I have datamaster.
#5
Re: What trim cell should I be in WOT??
I've seen the same thing with my logs. Even using the WOTblmblocker it only seemed to work for 1st gear. The CAT overtemp is the problem I found. Disabled that now. With larger cams forcing the blm's to rise at idle/closed throttle thats why I was seeing the blm adding additional fuel at WOT even though normal driving I was below 128 (except closed throttle). It was never the same though sometimes it would add other times it wouldn't. Tuning nightmare.
#6
Thanks for the info guys. I have to go out of town for a few weeks tommorow, but I will pick this up when I get back. I'm off to SERE school (if you saw GI Jane, you'd have a good idea). Joys of my job you could say. BTW, what format would you like a log? I have datamaster.
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General 1967-2002 F-Body Tech
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