So my 86 f150 302efi has been surging really bad at idle. I was thinking about the idle air control valve , I have cleaned it before an that helped for a bit . Would it be worth checking or just replace it. The truck dose have a 302ho out of a 88 mark vii if that makes a difference.

 

Being it did the trick once I would try it again.
I would also clean the port where it bolts on to, to make sure it is open.


I would also check the fuel PSI just to make sure it was with in spec and not adding to the issue.
Dave ----

 

Sometimes, a surging idle can be caused by a vacuum leak.

 

I have checked for leaks don't see anything. The engine was rebuilt with all new stuff about 6 months ago . Did all new vac lines and intake gaskets . I am going to clean it after work today. If that doesn't help next I'll do a smoke test

 

So I cleaned it an BAm the truck idle amazingly smooth now!! Maybe I'll just get a motorcraft unit just to have for spare. Thx for the help

 

Good to hear it was an easy fix and thanks for posting back what you found and the fix as it can help others.
Dave ----