EGR solenoid malfunction in damp weather?

[junkyardjeff]

I have a 95 F150 with a 5.8 that will not want to idle and fall on its face sometimes when its damp,thought it could be water in the gas and possibly a TPS but its acting like the EGR is moving when its should not or too much at times but will not do it long enough to diagnose or set any codes. So can the EGR solenoid short out and work when its not supposed to and I checked the EGR and it seems to be working.

[kb426]

My suggestion is to remove the idle air control and see if it's coked up. I have had them get gummed up and not work properly in the winter. You can unplug the iac and see what it does when the engine is warm. I believe that your 5.8 has the same intake as the 5.0 in my last project. If you look at the butterflys in the throttlebody, I think you will find each one has about an 1/8" hole drilled in it. I think the engine should idle when warm without the iac plugged in because of that.