Help!!!

I have a problem with my 88 b2200. The truck just shuts off it dont matter if I am going down the road or sitting at a traffic light the truck just shuts down but it does crank right back up. I have changed the fuel filter thinking maybe there was something in there that was blocking the flow of fuel but apperantly that is not the issue. Could it be that maybe the coil is going bad?

I dont know if its this but on mine if i hit a bump or just cruzing down the road my key vibrates back and just kills the truck. it might be the tumbler or ignition lock.

check all wires..like the ones on the coil,sometimes they get lose

OK I think I figured it out I replaced the electrical part of the ignition switch and it has not shut down yet and it has been a little over a week.