let me start off by saying ive read all the spark threads and done searches but nothing has turned up like my problem.
a few weeks ago my truck started idleing erratically at random times. plus or minus 2-3 hundred RPMs from where it always has.no codes at that point in time. then my water pump went out. so i changed it for a new one. after the pump change i got a P0118 code so i go a new ECT sensor and the code went away, along with the erratic idle. but then the motor would idle ver low like 550-600 RPMS. im getting good spark on all 8 plugs, and the plugs are in good shape. i did a tune up recently as well. but now in any gear except park if i let off the gas the motor idles less erratically + or - 100 or so RPMs for about 2 seconds and then dies. and if im moving down the road it just straight up dies if i let off the gas. if im in park then it idles fine for a couple of minutes and then the RPMs slowy drop until the motor dies. my vaccum gauge say i have about 19 inchs at idle in park

 

Yank the throttle body, and clean the crap out of it. Verify function of the IAC motor. (reset the PCM after you clean the TB.)

 

oops i forgot to metion i already cleaned the throttle body, and rplaced the IAC and reset the pcm, with no change. ive also unpluged both o2 sensor with no change

edit:air filter is new also

 

Tps??

 

forgot to add that one as well, its new. also i inspected my cap and rotor and there in great shape aswell.
i just started poping a code p0138. but idsconnected my o2s and there was no change. im to the point where i want to pull my hair out

 

ive replaced almost all the sensors that go on the motor. whats gettin me is that when im on the trhottle she purs like a kitten, always has. also i havent had a chance to get a fuel pressure ggauge on the truck. could it possibly be a fuel issue?

 

Maybe. but, if fuel pressure was falling off at idle to the point that the truck stalled, you would have other problems as well.

I would be tempted to take off the filter housing, have a friend idle the truck in gear, (sitting still please....) and watch the IAC valve, and see what it's doing. If it slowly closes off, till the truck dies..... I would take a long hard look at it, and the wiring.

 

ill see if i can get a co worker to help me out real quick
edit could high fuel pressure cause the truck to stall out?

 

i just went out and tested the IAC. i could not get the truck to stall out again. i even used my hand to completly cover the IAC port. the IAC opened and closed just like it was supposed to. and the entiere time i was pullin a steady 19.5 inches on my vac gauge

 

Of course it didn't do it..... you were WATCHING.....

Give it a couple days, see how it behaves.