i just bought a 88 f250 with a 5.8 and it idles around 2000 rpm. i have replaced the tps, and no change. i picked up a code reader, and it had code 32 and the book says egr. i am just trying to get a handle on the idle so that i can drive the truck. i have read all of the threads that are associated with idle, but none match my problem. any help would be great...

thanks jess

 

pull the iac motor and clean it. it controls idle. prolly carbon buildup on it.

 

thanks i will try that in the morning. i did clean the tb when i replaced the tps and i had the iac off i just didn't think about cleaning it. once i got it all back together i started the truck, and again 2g's. while the truck was running i unpluged the iac and no change. so i was kind of stuck.

 

If you unplug the TPS while it's running does the idle drop? Check that the TPS voltage is below 1v when the throttles are closed.

 

i took the iac off today and cleaned it. a large piece of carbon came out of it the size of a dime...

while i had it off i stuck my hand over the holes in the intake and had a friend fire it up, and it ran great. i put the iac back on and it works better but it still idles at around 1500 even after it is warm and you have to goose it to make it go down to around 800. and i have a slight hesitation when i get down on it.

so i am thinking i will replace the iac and see if that totaly cures my problems.

 

I have a 89 5.8l doing the exact same thing only mine will want to stall then idle high. What did you clean yours with how did you do it. Do you just take it off then put it back on with no adjustments.

 

There is no adjustment. Take a look at this: IAC Cleaning

 

Thanks cyrstal clear know. Going to go do that know and the tb, also got some of that sea foam see how she goes.