The Nissan Path

I have a 1995 nissan pathfinder, and the problem I'm having is that the engine starts and then stops immediately. I have changed both O2 sensors, tps sensor, and the fuel filter, fixed 3 broken vacuum lines, drained all the fuel and replaced with fresh supreme. I also replaced distributor cap, plug wires, coil, mass air sensor, fuel pump relay, main ecu relay, and the air filter. If the truck is left still for a while (overnight, etc) it usually stays running until the slightest bump (door shutting, hood closing) makes the engine die. I have checked every plug for corrosion, etc but to no avail. I just can't figure out what's wrong with it, it's mystifying. Any advice at this point would be great! Thanks.