1993 Chevy Astro 93 Astro AWD Won't start or starts and qui

I have a 1993 Chevrolet Astro that has passed an out of province inspection for BC. I boosted my wife's Dodge Caravan with no problems. I let the van run for awhile and then shut it off. My wife went out to start it later and it would not fire, or it fired and then stalled immediately and then would not fire. If I leave it for a few hours, it will turn over, seem like it's going to catch, and the odd time it has caught, and then quits within 2 to 3 seconds. Then it just turns over. I pulled the distributor cap off replaced the rotor and tried a new Distributor cap. I used some cheapo $7 plug wire tester that lights up if it detects spark (Some Canadian Tire Special) I was even dumb enough to hold a screwdriver to one of the posts on the distributor cap and got a good shock up my right arm. It seems it has spark (also judging by it catching and quiting) but it won't keep running. I can hear the fuel pump whining away for a few seconds when I turn the key on, but I am just baffled. It has been running fine (Though seems the idle was a little high) and the exhaust stinks like hell, but aside from that it was running just fine. Do you know what the problem might be? The plug wire tester was useless. Sometimes it picked up spark other times not. It had been looked over by Canadian Tire before coming to BC and looked over again by 2 mechanics since coming to BC. Before this happend. AS I could not getr to the plugs on the Driver Side of the vehicle from the Engine Compartment inside the van, I did not replace the wires or the plugs.