IAC or ECT

[stevealvey24]

ALright heres the story. If i start my truck up and take off while still cold it will idle at around 1200, but if I put it in neutral for just a few seconds it level out to 900, then 850 when in drive and be fine from then on. If I start it up and let it come up to temp the idle drops as it gets warmer and idles at 850 when put into drive. My question is does this sound like the IAC or the engine coolant temp sensor? Also if I put it in reverse when its cold it doesnt idle down real quick and it jumps into gear.

 

[robertc1024]

Sounds perfectly normal to me. They have to idle a little higher and run a little richer when they're cold to keep from stalling out.

 

[stevealvey24]

Alright forgot to tell one bit of information. Once the truck warms up it idles at 1200rpm, and while WARM if I put it in neutral it levels out. It go down to normal idle in drive unless I put it in neutral.

 

[robertc1024]

Well, if you're curious about the engine coolant temperature sensor, go over to fordfuelinjection.com. You can measure it's resistance to see if its withn specs. If you're worried about the IAC, yank it off and spray it out with some carb cleaner. They do get carbon build up in them, but they're easy to clean.