Intermittent Hard Starting / Rough Idle

[Sixball]

I bought a 95 1/2 Ton Silverado a couple months back. 170XXX miles. 350 Motor looks clean, unknown history, but it has a newer intake manifold with a throttle body 1 inch spacer, so some work had been done at one time. I drove it home about 60 miles at highway speeds, no proplems, no complaints. It actually has some pep to it.

But..... I replaced the serpentine belt and it wouldn't start. It would crank but not fire. I must have hit some wirring. It had some sketchy wiring right around the Thermostat, so I wiggled and it started. I then found when running, I could change from idle to rough idle by moving the sketchy wires. I cleaned up the wires, conected / sealed correctly and found a better grounding point. Problem solved. I thought......

Drove about 25 miles, start / stop style driving and at a stop sign it idled rough and died. Would not fire. This has happened twice now this week. Otherwise it starts and runs perfect. No catalytic converter. It has to be the wires. Anyplace to start looking? The wires I worked on were exposed. It must be deeper in the harnes. I know I will have to do some digging, but I was hoping for some things to look for. I'm more into carbs and not EFI.

Speaking of carbs. When this is hard to start at times, you have to pump the pedal luke it's carbureted. That seems like the only way it responds and eventually starts WITHOUT wiggling the wires at all.