Engine performance

[Ramdam59]

So i have a 99 5.9 and i replaced my valve cover gaskets, since then it has not ran right. i have an exhaust leak where the exhaust pipe meets the manifold not sure if that could be contributing or not but i have changed the pcv valve and checked high and low for vacuum leaks, though i have not found any it does sound like there is one. will start and idle fine and after it gets warmed up it will want to stall out and die, should i take the carb off and clean it? running out of ideas and just want to drive my truck so any advice will help. thanks

 

[Wile E Coyote Jr]

If you did the VC gaskets, check that your grommets for the PCV and engine breather element arent leaking. They can act like a vac leak if you used the old ones or installed new ones improperly.

 

[Daw14]

Get some starting fluid and spray around the base of the carburetor, and along where the intake manifold meets the block . If the rpm’s increase you have found your leak.