i have an 88 f150 with a 300 i6 and it wont idle below 1000 rpm, even with the idle screw all the way out. anybody have any clue whats wrong? thanks,
mike

 

I would guess that your distributor has turned, or more likely you have a vacuum line loose or off. I had a vacuum line off on my 460, and it would idle @ 1000-1100 rpm, found the leak and idle returned to 550-650


Marc
59-F100 4x4
91 F350 crew cab 4x4

 

pull the iac valve off and see if it is stuck open. they get all gummed up and dont move too well anymore.

 

While you clean the air bypass valve, also clean the throttle bores with a brush, solvent and a rag....it will idle way better regardless
Phil