89 gmc sierra idling problem?

[ugdude77@ymail.com]

i have a 89 gmc sierra and it used to idle rough the whole time took the injectors out and cleaned them along with the fuel filter now it wont crank unless i give it gas then it runs perfect until about 110 155 degrees then it idles up and down any help would be appreciated

 

[Molson02536]

i have a 89 gmc sierra and it used to idle rough the whole time took the injectors out and cleaned them along with the fuel filter now it wont crank unless i give it gas then it runs perfect until about 110 155 degrees then it idles up and down any help would be appreciated

Your IAC (Idle Air Control) valve sounds like it's dirty and needs to be cleaned or replaced, the other thing that would cause this is a sticky or stuck EGR valve. Try cleaning both first with Seafoam Deep Creep and also give your engine a good cleaning with Seafoam, your going to have to use two cans of Seafoam from the sounds of the amount of Carbon build up in your engine through your vacuum system.

Good luck and keep us posted. http://www.seafoamsales.com/