still having problem with shutting off

I have a 91 silverado w/ a 97 4.3 l v6... my problem is when i run the truck for a long time (maybe an hour) without shutting off or just shutting it off for mins at a time... the ilde gets lower and lower untill it gets so low that it just shuts off... ive replaced just about EVERYTHING there is 2 replace 2 fix the idle... the IAC valve MAP sensor spark plugs wires coil dist cap rotary... ive yet 2 replace the TPS but if that was bad wouldnt it do the same thing when the engine is cool? i also plan to replace the EGR valve but i doubt thats what it would be? what else could it be? the engine runs great only about 40,000 estimated miles on this newer engine... this is my only problem.... but its a manual so when it starts doin it i just hold the gas in a lil n let it rev kinda high so it wont shut off but id still like 2 fix this problem?

EGR can cause a low/rough idle. Other things to check are the Coolant Temp Sensor. If the sensor is telling the PCM that the temp is warming than it really is, the PCM will give it less fuel.

Last, but not least, you should check the fuel pressure when the problem occurs. The fuel pump could be weak when the pump gets warm.

//2000CAYukon

im probably goin 2 get an EGR valve sometime this weekend.... the coolant sensor is brand new cause i blew a head gasket cause it went bad n didnt know my truck was running hot so im pretty sure thats not it.. and it is pretty cold so the fuel pump should really get that warm with it being in the tank.. could it be the injectors? my truck is TBI

I don't think your problem is the injectors. If they were clogged it would not run good. Now it could be fuel pressure dropping, either the regulator or pump.

On some GM vehicles, the wiring harness at the pump get warm and that is when things start to go bad.

If you are using the 97 fuel rail, then checking the fuel pressure is easy. If you have the 91 setup, you need to buy an adapter to check the fuel pressure. If the EGR does not fix the problem, you really need to know what the fuel pressure is doing.

//2000CAYukon

thanx for ur help man... i found the problem... this mornin i started it up and it was runnin like shit... popped the hood pulled off the air intake n looked down in the TBI n the injectors were DRIPPING fuel... 1 was spraying on and off n the other was just dripping.. ima go ahead n get 2 new ones n get it over with