I have been trying to tune my Z for a while now, I have DST tuner for 96 LT1 and use ScanXL ElmScan to record the stats. I have fried one PCM and now have one with replaceable chips, but anyway I down loaded from another site a 383 file and loaded in mine, had to change injectors, gears on the contants, took several times changing different areas tuning for cruiseing, now what seems to be perfect scares me, all the cells show 0.0, all the way across the graph. What scares me is when I change the "open loop AFR Vs Coolant Temp. Vs Map" from stock to add more fuel for top end, change to 13.5 the hole tune goes out, starts idleing lean and then richens up at cruise. What I want to know is why the tune would change when this is open loop setting, I don't have it set for open loop running, open loop is set to stop at stock setting 40.25 C.
I have a WB and seems to be real close to what the scan tool saids. Any boby have any ideas as to why the tune changes so bad just by changeing the open loop afr.