Originally Posted by
HATEHPTUNERS
Sleeper-I'm very happy to hear that you are committed to getting it running right, and that you are not about just beating the truck to death. And no, I did not take your reply to be hostile-though you could easily have taken mine that way.
The fact you state the first tuner had you beating on the truck during the first few miles of it's life should have been your first clue that he had no idea what he was doing.. Any "good" tuner would have you holding the RPM's as steady as possible, at slowly increasing rate, so that accurate data could be collected. You want to avoid sharp, fast, transitions in rpm increase as best as possible. Also, unless he was using a wide band O2 sensor... he was essentially limiting your tuning to 4000 RPM or less... though some guys can tune higher than that with factory narrow bands... people like me cannot. Without a wide band, revving the motor up above 4K was essentially just wasting your time, his time, your money, and setting you up for a crappy tune.
Right now.. without making any other changes.. you can try the tune posted above from kevin87turbo. You can see that he has smoothed the VE table considerably in an attempt to get rid of your low rpm lean condition. With his tune, go back in and DISABLE the MAF sensor so that you are running OPEN LOOP off the VE TABLE and do some nice and slow driving while logging keeping your RPM's under 2000. Once you get the VE table completely smoothed out from idle up to 2000, then you can start trying to tune from 2000 up to 3000 rpm. You can do this by pulling the shifter all the way down into L1 and then SSSSLLLLOOOOWWWWWLLLLLYYY accelerating from a dead stop, all the way up to 3000 RPM.. then make your changes to the VE table and go from there... It is absolutely essential that you get the VE table as close to perfect (+/- 3%) as possible as that is the table that all other fueling calculations are done from. if you want, just turn off the MAF, and do a log of a short drive keeping the RPM's under2000. Post that log and then we can make corrections from there to get you dialed in.
Learning to tune takes a LOT of hours, a lot of TIME, and a lot of trial and error. I would say it's going to be at least 100 hours of reading and studying to even get a basic understanding of what you are doing. With guidance though, we can keep you out of danger, and get you where you need to be. For now.. focus only on VE Table tuning, and KEEPING the engine RPM's down until you get fueling dialed in. From your short log I can see you have idle timing set to 23 degrees, but the computer is pulling timing.. that is *usually* an indication that your BRAF is off (high), or your fueling is off in the idle areas of the VE table (which we can kind of see using a LTFT/STFT average graph on the same scan).. the timing jumping all over the place at idle at the beginning of the log is also telling you the fueling is off. When fueling is spot on, the timing will be relatively flat with little bouncing or fluctuation at idle.
Once you turn off the MAF, then we will know for sure which direction you need to go. Right now with blended MAF and VE... it's very difficult to recommend changes. Do you have a wide band O2? Or are you relying on the factory narrow bands? Either way, we can get you up and running, and idling, and have good throttle response. So, for now... turn off your MAF sensor, set the tune for OPEN LOOP, and give us a log of you driving it while keeping the RPM as steady as possible, and keeping the RPM's under 2000 RPM... it will be easy to get a baseline tune going from there.
If you are not sure how to set up the tune for OPEN LOOP, MAF DISABLED... just post back and I will be happy to post up your current tune with those changes made.
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