2001 Firebird tuning issues. nasty looking maf and ve curve stalling high roll idle

[scdude]

hello, the car has a 383, 230 afr heads, magic stick 4 cam, fast 102 intake and tb, 42s, and 104 maf housing with card maf.
The car starts and idles amazing and pulls good at wot afrs are good, but it idle hangs coming to a stop but not at first. It starts hanging at 1200-1500 then over time will move up towards 2000. Sometimes the car stalls and almost dies coasting to a stop. it also pulses sometimes driving nice down the hwy. Anyone have ideas or have had this before?

[scdude]

thought it might be a vac leak but have yet to find one. fuel system holds pressure good but I am not sure what fuel pressure does while driving.

[lukearmstrong1990]

likely the TB blade is allowing too much air past on coast down.

cheat fix would be to use the 0.20-0.08 1200rpm and 1600rpm areas in the idle spark table and enter values like 6 or 8 to force the engine to labour and reduce RPM.

otherwise reduce the blade angle and recalibrate 0% TPS and re-calibrate the adaptive idle, rolling idle, throttle cracker and follower sections.

[scdude]

worth a shot for sure