Engine will not Idle?

Bad or stuck open EGR valve does exactly what you're descibing.

This is a 1995 1 ton dually, 4wd, manual with a 454.

I'm baffled because this has been going on for about a month. The day it started I was driving a gravel road at about 45mph. Everything sounded fine and it just quit. Like I had turned the key off. I coasted to a stop. It would crank and crank but no fire. I did find a wire to the oil sending unit was melted to the exhaust manifold which shorted it out and caused it to quit. So I replaced the bad section. It fired up but runs like crap. It won't idle. You have to keep your foot in it to keep it running. It has 0 power.

I've replaced the fuel filter, fuel pump, fuel pump relay, spark plugs, spark plug wires, cap, rotor, ignition module, ecm, egr valve, map sensor, pulled vacuum lines apart and put a blower to them. I've ran a compression check and everything is at 125psi.

I did find a leak in the driver side middle section of the intake manifold. So I pulled the manifold inspected it with a straight edge for warpage or cracks. It appeared good. So I reinstalled with new gaskets. Once reinstalled it still run the same. I sprayed intake cleaner all around the intake and throttle body and didn't hear any change in the engine.

Any idea's?

Jeremy

It will idle at about 1700 rpm when I unplug the map sensor but still has 0 power.

Amazing! I have the EXACT same problem. I could have written your question. I have done everything you have done and more. Replaced fuel pressure regulator in tbi. My ignition module, cts, tps & egr all checked good. Timing is good and have 16" of vacumn. Replaced coil but it was good. I went so far as to remove cat and muffler to check for plugged cat. No luck there so don't bother doing that. If you find a solution please post it on this web site so I can see it and I will do the same if I find it first. Thank you.

Triplxxx, Does your truck have a parasitic.66 amp current draw when it is shut off? Mine does and it might have something to do with the problem. You can check by hooking a dvm or multimeter set on the 10 amp scale between the battery neg terminal and the neg battery cable when the cable is unhooked. This will run current from the battery to the battery cable and you will be able to see it. You must remove the under hood bulb mounted on the underside of the hood or you will read that current draw. You should have only.200 amps max which is used to hold your radio stations. If this is present on your truck I might be able to find the problem from there. Oneton

My 95 chevy silverado with a 5.6 liter engine will crank fine. But you must keep feathering the gas pedal to keep it running. It will not idle on it's own. I replaced the fuel filter a few months ago but then it was cutting out. This idle issue is nothing like the events that caused me to replace that filter. The truck has 113,000 miles and has been maintained well. However I have never replace the egr valve.
Last week it did this same thing, once and never again until this morning. This time it was too bad to actually drive, every time you would let off the gas it would die.

Check all your hoses for vacuum leaks, and listen for the hiss of a vacuum leak around the throttle body. If everything is good you may have a fuel restriction somewhere else. It could also be the ignition, inspect it thoroughly.