91' gmc 1500 5.7 keeps dying

[BPB]

The truck idles fine, when you drive it the stupid thing wants to die. if you pump it lasts longer, but it died like 12 times in a one mile trip. I know it is a sensor, I just don't know what one. it has TBI if that helps.

 

[87manche]

have you checked the fuel pressure?
when it tries to die does it stumble when you first hit the accelerator and then pickup, or just die?

 

[BPB]

some times it will go, but it just dies you have to pump it fast to keep it going.

 

[8Mud]

Sounds like the IAC may be sticking, if you remove it to clean it be carefull, the rod for the piston is pretty fragile and bends easy.
May also be the EGR sticking open or the springs are weak and it is opening too soon. When the seat gets junk in it, this is usually a gradual thing, it will stall at stops or when idling. If the spring breaks, it may stall off idle.
The pressure regulator on the TB is a known sore spot.
If it idles fine and runs at lower RPM, then dies at higher RPM's why not check the fuel filter and them maybe like mentioned the pump and/or pressure. The filter is pretty small and gets full of junk quick.
I had some serious and repeating head gasket problems in my 88 K1500 5.7. Any coolant coming out of your exhaust?