I have a 91 with a 5.7, just the past couple of weeks it has started idling really low, cold startup is normal but once it gets to normal operating temp it acts like its thinking about dieing 'though it never does' when i stop at a red light it will idle fine for a few seconds then drop to a low idle irratic lope.
cap, rotor, wires, plugs, air filter, all fresh. egr checked and good. checked for vacume leaks, none. ran injector cleaner several times when i first noticed the problem, no change. i installed a mild cam and double roller chain 8 mos ago but dont think thats the problem since in every other way the truck runs great, no millage loss, no stumbles, missing, or flat spots through the power curve,
at 170.000 it burns about 1/2 a quart through the guides/seals between oil changes but thats expected.
now as i bang my head against the hood i keep wondering what in the he// have i missed.
one other thing for the tech's out there, i thought the problem might be the coil arcing against the bottom of my air cleaner since the connectors on top of the coil rub the bottom of the housing slightly so i mounted my stock coil horizontaly on the firewall above and slightly to the side of the distributer, now i have a humming noise coming into the cab from behind the dash in the area i mounted the coil, the hardware through the firewall is free and clear of anything behind the dash,
i have remote mounted a few of my coils in the past, though never this style, do i need to isolate it with rubber mounts, and if so do i need to run a ground? i mounted it solid thinking it might draw ground from its mount.
any information,thoughts, ideas, proceedures, insults, would be greatly appreciated, im completely at a loss at this point.