The truck won't stay running. It will suck air on the gas and pick up when I let off. Idles up and down. I have changed tbps, O2 sensor, air idle control value, and map sensor. Vacum leaks don't seem to be the problem. I can unplug the map sensor vacum line and it will idle up and accelerate fine for just a few seconds. Will stall if I don't put the line back in and then stall if I don't pull it back off. Fuel pressure is ok, changed fuel fillter too and spark plugs. Also the distributer cap is only a few years old and if I try to turn it, it shocks me. Any suggestions would be greatly appreciated.