Slacker, 8 am (6 here) and your just starting your coffee
Here are the PIDS from when it's not acting up:
Normal idle, not moving...
Coolant volts-1.1, temp 194° F
TPS volts- .76, position- 0%
Min TPS- .76, Spark advance- 4 to 6
Upstream O2- .1 to .8, downstream- .6 to .75
Short term trim- -5.7 to -9.6, long term- -13.9
Target IAC- 20, actual- 20
Desired idle (this never changes)- 752, actual- 736
Load value %- 6 to 7
Notes from normal operation; Sitting still, rev up to 3200ish rpms and hold for a few moments. IAC settled in at 90 steps. Let off throttle, idle falls smooth to 736, IAC falls smooth with idle to 20.
Notes when acting up (moving only tonight, won't act up sitting still); After holding steady throttle at 3200 rpms, all info within expected ranges (IAC 90, increased timing, slower O2 response but in same range as idle ECT...) Take out of gear and release throttle. IAC jump 10 to 20 steps higher (100 to 110) then falls to 60 to 68 (target and actual) as idle falls to 1280. At this point the IAC adjusts to maintain 1280 rpms, to the point of going wide open (190 steps) if I put the truck back into gear and apply brake to pull the idle down. This carries on for anywhere from 5 to 45 seconds, then it falls smoothly to normal idle.
Just like taking an intermittent problem to a shop, it won't act up when it's suppose to. The idle will normally hang when sitting still in the same fashion as it did moving today.
I'm thinking about setting up the neutral safety on a switch to see if that makes any difference. It is just grounded out since I did the manual swap. I'm not sure why it would make a difference now when it ran fine like that for a few years before the 408, but I'm out of ideas. I also need to switch back to the stock tune (if the it will run on it still) and see if that changes anything since I'm not sure how Hemifever sets up his trans delete tune. Guess I should try Ryan's last tune too since he hasn't done the trans delete. They were all acting the same the last time I tried them.