technical

I was looking at some logs when I noticed that under a certain situation my LTFT's go as low as -12 . This occurs under part throttle/light load as the map values increase relative to the increase in throttle ~2500rpms.

Do the settings in the PE Modifer/RPM table have effect here? I'm trying to figure out why the PCM thinks it should be adding so much fuel, but then backing it off.

StealthV

Short answer - no.

Sounds like your VE and MAF need to be calibrated.

P Mack

iTrader: (6)

Your VE may be too high in that area. PE doesn't have an effect until >60% throttle at those rpms. You can see when you go into PE by monitoring the fuel trim cell or commanded a/f ratio.

technical

Thanks. I figured as much, but I wanted to make sure that I didn't start chasing my tail while trying to fine tune.

technical

I've isolated the problem, but I'm not sure if the MAF calibration is off or if it's just the ve. I'm starting from a modified tune and don't know what the factory values for the MAF were. Does anyone have a stock MAF calibration for comparison?

P Mack

iTrader: (6)

You can download a stock .bin file from the sticky at the top of the forum.

technical

Thanks. I didn't even think to do that. I saw "HP Tuners bin repository" and figured it wouldn't work for me.