2000 F150 4x4 4.6L. Morning cold start is difficult. I cycle crank engine 3-4 times before it catches and then it runs ok but only 900 rpm ..normally should be 2000 rpm on fast idle. I removed "IAC" solonoid and cleaned, freed it up with brake clean solvent, but didn't change a thing. Engine runs great when warm and restarts easy all day except when I cold soak overnight. I would appreciate any help.

thanks Gauge7

 

did you cold cycle IAC to check operation?

let truck sit overnight.......leave unbolted but plugged in.....have friend help you while you look inside IAC

have friend turn ignition on and off a few times to check that the piston inside IAC moves to seal the bypass...(no need to start engine)

good luck

 

I'll try that option, thanks, and how far should piston move and will that amount of travel confirm it's in good working order. If piston doesn't move at all does that mean solonoid motor is inop or can I first check connection for power and ground circuit. If IAC is good what else will cause these symptons?

Thanks, Gauge7

 

piston doesn't move much...just enough to seal the bypass.

if no movement...check harness with multimeter..

you need to put a scanner on it...

if you don't have a mechanic buddy to scan it for you.....purchase a USB ODB-II interface for your laptop/computer offa Ebay for around 20 bucks....and download free software to check for codes..