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Tuner in Training
CSFI to MPFI with rich condition
hey everyone.
i upgraded my 98 chev 1500 with a 4.3L to MPFI. got rid of the CSFI due to a failure causing excessive fueling. it ran find and after letting it sit for a week, LTFT were easily -18 on a tune i have had in this thing for several years and 75k miles. diaged and replaced. truck runs well with new injectors and figured i would do a fresh tune with the new unit and get back into tuning the ecm (previously this was the wifes daily).
starting out i wanted 14.1afr and adjusted accordingly. disabled DFCO, unplugged maf (still reporting code), disabled closed loop via coolant temp.
what iv noticed is the majority of the VE table is -2 with the exception of idle and surrounding squares. those were in the area of -10ish STFT. copped ve table after drive and paste % into VE tune table. retuned ecm and restarted. pretty much same exact thing happend, most of the table was -1 while idle and surrounding squares were upwards of -8. pasted% onto table and restarted. same result. at this point i feel like i can sense the truck is down on power and trims really dont seem to be changing.
its be a long time since i have done this and just need some help to determine if its something im doing on the tune or do i need to dig into the truck further.
i included the tune i was using to adjust VE as well as a couple of the scans i used to get data.
4.hpl
5.hpl
6.hpl
98 4.3 performance tune ve tune.hpt
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You need to adjust your secondary VE table as well. I just copy/paste the primary the rows one by one.