Fleury_XLT

HI, I have a 1990 f-150 WITH a 5.0L engine. Here my question : at cold start, the engine have difficulties to idle correctly, then, when the engine get warmer, it begin to rev faster, then faster.... SOmething around 2500 rpm at idle... I've cleaned up and reseted de IAC, with no luck..

Any suggestions ??

THANKS, Luc

Fleury_XLT

Anyone please ??

techrep

iTrader: (1)

Does your 5.0 have a trottle body or carb ??...If it has a trottle body, there are two sensors on it...1 throttle positioning sensor and 2 idle control sensor...both can be removed and cleaned with carb cleaner...I ended up just replaceing mine. Good luck

Fleury_XLT

Yeah I have a throttle body !!

Fleury_XLT

Do I need to remove the throttle body to clean those sensor ?

techrep

iTrader: (1)

Its easier...but I think you can get both them out without removing it...I took mine off and cleanded all the gunk out also with carb cleaner...run sweet after that.

BigGreyBox

I would make sure it dries out good too after you spray it. I've had luck cleaning the IAC on my f150, but on my old ranger I had to replace it and the tps, they wouldn't work even after cleaning. So if cleaning doesnt help, it doesnt mean that still isnt the problem.

Fleury_XLT

if the engine start to rev really fast when it war, does it means that the IAC need to be remplaced (I've cleaned it with no result)??.

techrep

iTrader: (1)

Its one of the 2 sensors I mentioned...trust me...mine did the same exact thing...the problem is I changed them both at the same time...don't know which one fixed it...cleaning did no good but like greybox said...just because you clean it it still may be bad. I think I paid $90 bucks for both at Advanced.

BigGreyBox

I would start with the cheaper sensor (dont know which that would be), buy it, try it, if it doesnt fix it then keep it anyways and go get the other and install it too.