There are so many issues, I feel like I must be missing something fundamental. I've spent the weekend attempting to tune my LS3 swapped '94 TransAm. It's a crate LS3 with a 216/226-116+3 cam. I have an AFR500 wideband and hptuners. Up until this weekend I was using a stock 2002 TransAm file with my old MAF table from the LT1, the spark table from an LS3, and fuel tables for the LS3's 39# injectors. For both VE and MAF tuning I turn off LTFT's, closed loop, and power enrichment. I have the same issues with both MAF and speed density modes.
First problem is the car runs lean in general after a warm start. It runs lean for a few minutes before snapping out of it. I've found other threads on the issue but no resolution. After a few minutes of driving I can finally start recording data.
Even after dialing in idle it will still lean out. For instance I could come to a stop and idle will settle to 14.x but after a few seconds it pegs at 16+. I have to adjust it way rich to prevent this from happening. In closed loop it will lean way out, then the PCM adjusts the fuel to bring it back to stoich, then after a few seconds it goes way rich and gets adjusted back the other way again.
When tuning MAF, if I got in the throttle to hit the higher cells it would lean way out then after a few seconds it would peg itself max rich, like 9.0/1. I feel like I must be missing a table somewhere that's affecting my fueling. This only happened at 5,000hz and up.
My VE table looks like no other table I've seen. Looks like it has a growth on the front and a huge chunk missing in the back. It is the culmination of hours of driving and applying data though. I was facing similar issues where one minute a cell would read one AFR and if I were to revisit the cell later it might read a totally different AFR. Made tuning very frustrating.vetable.jpg