That is strange... run this tune (LTFT -1 to -3 % range) and capture a few logs... if it runs good then keep it, if wideband shows PE fuelingis not rich enough, then increase PE table B3618 a little.
( I've seen strange stuff, not to worry )
That is strange... run this tune (LTFT -1 to -3 % range) and capture a few logs... if it runs good then keep it, if wideband shows PE fuelingis not rich enough, then increase PE table B3618 a little.
( I've seen strange stuff, not to worry )
( log in post #1 shows MAF under-reporting )
Post new log/tune files.
What do you mean under reporting? i have been working with the tune I made and have it -3 to 0 while cruising and the wide open running at 12.9 on the wideband. I have had a little idle problems "-7 trims" but think I got that dialed in pretty well now. Truck runs fine. I drove 40 miles and was getting about 18mpg on the highway so that's not too bad.
MAF is not reading a sufficiently high value for the TP and RPM... I'll post a pic shortly...
do ya think the maf could be bad making it run lean? The guy I bought the truck from said last year it threw a maf code so he cleaned the maf and after that the code never came back. Makes me wonder if there is something wrong with it possibly
well just for kicks I ran down to the local salvage yard and grabbed another maf and put on it and flashed it back to all the stock fuel and air tables. It was much better but still running a little lean. was in the +5 trims. So I just bumped the maf table 5% across the board and now the trims at cruise look great. now I have a kinda rich idle though. Here is a log I just ran at cruise and idle at the end of the log.
An update on my truck. I have been playing with the tune ever since I started this thread. I have changed pretty much everything in the tune and had it running good. Just installed a set of headers so I have been playing with it again. Just seems like I would have it dialed in then it would change a little. Well today it tripped a light with a MAF code like it did a year ago. Guessing the maf is not quite right since it threw the code a year ago. I kinda wonder if this is what has been causing alot of my problems. Tuning around a bad maf. So I threw on the spare maf I bought and went for a run. She was running super rich and wide open was like 11.1 afr. So adjusted trims and got the wide open set back to 12.9 now. So I wonder if that MAF was causing alot of my problems? I'm still running the sloped IFR table even though it had the flat table but my trims are pretty good. Cruising it is -1.4 to about -3.9 so seems pretty good overall.
What MAF code did you get?
It was a P0101 code. The guy I bought the truck from said he got that code so he cleaned the maf and it never came back. That is till today. I cleaned it again but then decided to just put the new used maf on and try it.
P0101 can mean problems with the MAF sensor, but it doesn't necessarily have to be a problem with the MAF sensor. You get P0101 when the MAF's reported airflow is not in good agreement with the VE table's calculated airflow... so if you've been messing with the MAF curve then it can throw a P0101 if the MAF no longer agrees with the VE table.
GM had a few different MAF sensors for different vehicles... they had different part numbers and they all read the airflow differently. I'm guessing that your replacement MAF sensor has a different part number to the original, which is why your fueling suddenly went super rich.
If your getting good fueling with a sloped IFR table, then there's possibly something wrong with the manifold referencing function of your pressure regulator.
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