i got a 98 5.2 and i am having a problem when i accelerate on a cold engine. i will go to accelerate and the engine will nearly stall out. and then i let of the gas and accelerate again and it is perfectly fine. anybody know what this could be.

 

Cat gettin plugged?

 

not jackin your thread... but i have the same kind of problem. im runnin the 5.9 and it only happens when i put the pedal to the floor from a stand still, it will bog way down, throw a small cloud of black smoke, then take off like a bat out of he!!. not that its a huge problem for me but i hate seing smoke. and im wondering if it is the cat. i took my 02 sensor out (pre-cat) to relive pressure and it didnt help. thinking maybe injectors dirty? and cant keep up. once again sorry if i jacked ur thread. maybe we can both get some good answers.

 

sounds like a vacuum leak to me.
mark all the hoses clearly, then plug off all the ports on the on the side of the manifold and see if it acts better. if so, then inspect them, or add them back one at a time to find the culprit.