make sure you didn't install the IAC backward as well I got .6V out of Chilton's, I can post a scan if folks are that interested

 

It was a vacuum leak on top vacuum hose on tb....purrs and has power!.....after warm up the rpm with go up and down slightly punch the throttle and it fixes itself....iac? Even tho its new?

 

congrats! you need to clear the trouble codes and drive it for a while then check for codes again

 

dup

 

x2. Put some miles on it so the KAM can rebuild.

 

I didand have reset the computer after every adjustment....now i got a code for map sensor out of test range...it a new code for this truck.

 

glad you found the vaccum leak I suggested! it happened to me... little sucker is hidden right there in between the TB...

If your not stalling your IAC is fine --- try the TPS instead... worked for me when I had your issue

 

can't help with your map, mine is maf sorry

 

I recently replaced the TPS on my 93 F150 XLT with 302. It seemed sluggish after the replacement, and searching the forum here identified the voltage issue.

I pulled off the TPS, opened up the mounting holes for more clockwise rotation, and set the idle voltage to 0.98V.

Runs better now. Thanks for all the good advice here on the forums!

Next move, advance the timing 1-2 degrees...

 

ANYTIME you replace or mod a sensor, or replace a component that a sensor monitors on an OBD1 (pre 96'), disconnect the battery for a minimum of 5 minutes to clear the KAM (Kept adaptive memory). It will then rebuild using any new sensor input, rather than building on top of the old crap it was getting out of it.