When my truck is idling, and I give it a little gas (5% of WOT) it will hesitate, dip to less than 500rpms idling, then rev up. It also has a shaky idle.

I have cleaned the IAC valve with carb cleaner, I think my only other options are TPS and spark plugs? This has followed me through 2 sets of plugs, so I don't think it's that. I did put the 'wrong' plugs in, 3923s...so that might be it. Suggestions?

 

I would go for a new TPS check for any vacuum leaks you may have one from what you describe an air leak will do that.

What engine do you have maybe you have that plenum leak problem going on.

info LINK

 

It's the 4.7. I am going to replace the TPS and see where that gets me.

 

I'd lean towards a vacuum leak.

 

Vacuum leak would be cheaper to fix...and quicker...

I'll let you know how it goes.