I was getting a surging at idle and at a stop it wanted to stall out so I took the throttle body apart and cleaned it up. Took out the IAC which is less then a year old and cleaned it up. Reset the IAC multiple times and I think i've got it right, however at operating temperature when data logging it reports the IAC at 0 counts. Not sure if thats good or not?

My second concern is that the voltage on the TPS sensor reads .55 volts at idle and 4.35 at WOT. I dont want to run out and drop $60 on a new tps if I dont need one. Does this sound like its in the right range? I thought that I read somewhere that anything over 4 volts at WOT is ok. I am using tunerpro rt to pull the voltage readings as well.

 

Seems to me your TPS is working correctly. One more check would be to manually open the throotle from closed to wide open while watching the TPS voltage. The voltage should increase in an orderly manner, never jumping around.

The IAC = 0 is a problem, and maybe not your only problem. At idle, you should have maybe 20 counts. Also, I noticed on my car that the IAC counts increases as I accelerate (did not know this before). You need to dig into how to remove the IAC and get it back to the factory position. There is a special procedure for this on this board somewhere.

 

When I set my IAC, I used, 1 1/8" length from end of IAC to the face of the gasket. This is the OEM number. More length means less air, less length means more air. The end of the IAC being closer (less) or farther away (more). Lots of info on how to set and clean.



Then by adjusting the throttle stop screw, set IAC counts to (just at zero) when at normal engine temp. Doing this will settle down a wandering idle speed a bit. This will not stay perfectly at zero IAC counts.

OEM floats at 20 at idle, runs in the 100's when cruising.

IAC, spark, O2 sensor, Vacuum (lope?), Carbon build up(egr, T-blades) and small air leaks (egr, intake, v-lines?) will all "play faster/slower games" with the desired idle speed. Somewhat like a slow "roller coaster".