Truck is not running well...need help

[87shrtbd]

I'll explain this to my best ability.

Idles fine most of the time. Has a miss here and there. I can be driving and all of the sudden, it quits idling and won't run for squat. Feels like a stopped up fuel filter. REplaced that, carb needed replacing since the screw holding the baseplate and body together had wallowed out the holes and jacked the body beyond repair. Ran fine after the carb replacement for about 2 miles and quit. Sat for a few minutes and cranked up but wouldn't run off of idle. Idled it home in 2nd gear. As soon as I touched the gas, it died. Then it wouldn't idle. Sat for 2 days and runs fine.

Things replaced:
Carb
F Filter
Coil (no points so no ballast resistor and the coil is hooked up right)
Got spark now, don't know about when it's acting up.

My thinking is:
Stopped up exhaust? (no converter, semi new muffler)
Computer?
Fuel pump?
Dist.?
Something in the tank?

Running out of patience. Got any clues? Slant six, man 4spd od

[Speed Dragon]

I'd check the choke for proper operation, and check the fuel flow when it acts up. Also, could be the pickup in the distributor, they've been know to cause weird problems.

[B-300]

I check the coil. Is it leaking? Coils have oil in them to conduct the heat. If they loose this oil they will overheat and cause a weak or no spark. (Only a round, sealed type)
Also will it run with the vacumn hose disconnected from the distributor? Sometimes when a pick-up fails the movement of the wires by the vacumn advance will cause a miss or even cause the ignition not to trigger.
--B-300--

[87shrtbd]

New coil, no vacuum to dist. It is computer controlled.

[WARLOCK]

think fuel pump

[needa440please]

This sounds similar to my woes. Was this ever resolved?

Just out of curiousity what is the operating pressure between the pump and carb on a 318 2 barrel ?

[spag]

my 88 D100 I use to have did this every now and again. I ended up selling it before I fixed it. I know for sure it wasn't the coil or the computer, they were both replaced.

[Speed Dragon]

You may need to check the wiring is everything else checks out, that's been known to do weird things too. Check for vacuum leaks, also check the carb base gasket, it could be bad.

[sgillett]

I had a fuel pump go bad where it would pump enough at idle and just above idle but as soon as I tried to accelerate or pull a hill it would run out of gas. When I opened up the fuel line at idle it sprayed gas all over but there was not enough volume to supply the carb when the RPMs came up. The spring inside the pump broke.
My $.02
Scott