Having a little problem with the idle on my truck. WHen i start it in the morning it will rev up to around 2 grand then drop to below 500 and almost cut out. Once the truck is warmed up and i'm driving, i can push in the truck and the idle will stay at 2 grand, then drop, then go back up. I'm thinking idle control valve. any input?

Thanks!

 

Probably. Have you done the plenum fix yet?

 

I have not, I plan on checking that soon. I know there is a lot of topics on this already, but, how do you check it?

 

Pull of the air box on top of the throttle body, crack the throttle wide open, and look down in there, see oil? Plenum is blown.

If it hasn't been done on your truck yet, it is a good idea to just do it. Get the hughes plenum plate, and install kit, and down the road you go. about 140 bucks total, including shipping.

 

that is one way to check but another more time consuming way would be to pull the throttle body off and get a mechanics mirror so you see towards the back of the intake where the oil likes to pool. but more than likely it is the plenum

 

It's a vac leak somewhere. Check the throttle body gasket. It's likely the plenum. On mine, I had blown intake gaskets on the #7 cylinder port, blown plenum, blown throttle body gasket, leaking injector o-rings, and a split PCV hose. The whole manifold was one giant vac leak. Did the plenum and changed all the gaskets, and it works great now. No vac leak.

 

A bad TPS would also do that.

 

Checked the pleunum today, all looks good! the mechanic at the garage i work at said he replaced it last year on my truck. Ordered a new tps, hope this will solve the problem

 

is there a way to know if the plenum fix has been done just by looking at it........

 

Use a mechanics magnet. (magnet on the end of a stick, basically) and see if it sticks to the plenum pan. If it does, you can look forward to doing the repair.