5.7 TBI 5-speed stumbles when I let off gas

[skunkfunk]

I've got a 1991 K1500. The initial issue was stumbling under load. I replaced the fuel regulator and the EGR solenoid (due to a code) and that seemed to fix the stumble under load. Now I have this most curious symptom wherein it stumbles when I let *off* the gas. If I leave it in gear and let off, say on the interstate, it does this weird lurching for a while. Pushing in the clutch in the parking lot also sometimes makes it think about dying, though it hasn't yet.

Anybody else had this issue?

 

[livelifewideopen]

Idle air control, or EGR valve itself not just the solenoid. when my 88 tbi 350 5 speed used to not run at idle it was a bad EGR valve. this isn't an expert opinion just giving some input tho haha

 

[Lewis1129]

I had a similar problem with my 91 5.7 5 speed. It would do it real bad in parking lots and drive thrus and places like that. All I did was removed the vacuum tube running to the egr valve and capped it at the source. Solved it completely.

 

[skunkfunk]

Turned out to be the EGR valve. I was convinced that couldn't be it...