2002 6.0 4x4 Chevy 2500hd

[CraigV]

Pickup idles fine and goes down the road until you have to to put the throttle down and then it falls flat on its face till you let up to about 3/4 throttle and then it goes down the road even sitting in park and smash the throttle down all the way it falls flat I. It’s face

 

[jrsavoie]

Pickup idles fine and goes down the road until you have to to put the throttle down and then it falls flat on its face till you let up to about 3/4 throttle and then it goes down the road even sitting in park and smash the throttle down all the way it falls flat I. It’s face

Check fuel delivery

 

[smokymtn65]

Any codes? Have a fuel pressure test gauge?

 

[MrMarty51]

When was the last time the enjun hadda thorough tune up ?
Air filter clean ?

 

[MrMarty51]

Oh yes, pardon My manner Craig V.
Welcome to the forum.