If I start the car and just let it warm up to closed loop without driving, the idle is pretty good. I lowered the O2 constant to 500mV because I had high BLM's but it smelled very rich. Now the BLM is around 130 and it only smells a little rich. Idle IAC count is around 20-30, TPS is at .65V (I know it's a little high but the ECM sees 0% TPS until about .9V so I haven't adjusted it yet). After driving around for about 15 minutes, the idle is really crappy. It hunts between about 500-700, IAC is at zero (even though commanded idle is 750). After a couple minutes it seems to level out again (not sure if me playing the throttle has an effect on it recovering).

My p/t issues are if I'm cruising around and push the clutch in, the engine speed drops to around 500 for a couple seconds until it recovers back to 750. I think this is an IAC issue but I'm not exactly sure what to change. The other thing is at high RPM/closed throttle (like when you downshift), it backfires until you either drop to idle or push on the gas to accelerate.

Here's a datalog showing the hunting and backfiring issue:
http://www.fabiens.org/alex/v4a-5hun...20backfire.xls
This is the idle after just letting the car warm up without driving:
http://www.fabiens.org/alex/v4a-2IDLE.csv

I'm running SAUJPv4 changed to manual mode. The engine is an L98 with 200cc Pro Topline heads, LT4 hot cam (218/228 at .050, .525/.525 lift, 112 deg LSA), LT1 intake conversion, 24# injectors, short tube headers. Trans is a T56 with 3.42 rear. Base spark is 8 degrees, injector constant has been changed.

Thanks for any help!