I'm working on a 91 1500 w/ 350 tbi. Under acceleration the truck seems to hesitate/stumble like its about to stall. The engine has recently been rebuilt and I don't think there are any vacuum leaks. The spark plugs are new and should be correctly gapped. I've also checked the timing and coil, both fine, but haven't yet looked over the cap closely. The spark plug wires seem to be okay but I haven't checked them with the ohm meter yet. The injectors have been replaced and the fuel pump was replaced maybe a year ago. The fuel filter, I believe, was replaced at the same time as the pump. Now I know there's a chance that the problem might the dist. cap or the spark plug wires, since I didn't examine them very closely. But I would like some input from anyone that has any other ideas of what the problem is.