92 f150 4X4 5.0 had low idle so i cleaned egr and tb also cleaned idle control now it idles at 1500 rpm in gear and 2000 -2800 rpm in park . what can cause this thank for any help .this is my first efi ford

 

Have you checked for codes?

Just because you cleaned the Idle Air Control Valve (IAC), doesn't mean that it isn't faulty and needs replaced. You may also have a vacuum leak somewhere. But to save yourself ALOT of trouble, check for codes first.

 

Throttle positioning sensor or idle control sensor, both located on the throttle body, check all vacum lines

 

try unplugging the iac. if idle doesnt change then its bad and you need to replace the iac

 

when i unplug the iac it dies

 

k that means thats working. could also try throttle position sensor like said above or u have a vacumn leak somewhere

 

thank you i will check for vacum leak .i am going to check the upper intake gasket and replace it

 

If it's constant & not surging, check your throttle cable for binding or hanging. Make sure it's getting full travel. Do the butterflies close completely?

 

i took both lines off going to breather started the truck and put my hands over tb and it idles just maybe 200 rpm lower i guess major vacume leak ? maybe upper intake gasket?

 

maybe going to salvage yard and get idle control valve off another 92 5.0 just going to try that