Ok so I bought a 1984 W150 with a rebuilt 360. only 1500 miles on rebuild but it was a hunting truck so the rebuild was 6 years ago. truck has been sitting but fuel smells good and the PO just filled with new gas. I drove it home and drove it around for two days maybe 40 miles total. driving it yesterday it started to miss and backfire when I would try to give it gas, so I just held the peddle enough to keep truck moving, then it got worse and died. pulled off the road and tried to start it back, it will fire right up for a split second and die, will do that over and over, I let it sit for a few hours to cool down to see if temp changed anything and it still did the same thing start right up and die. any ideas? I did cut the mufflers off and drove it around maybe 15 miles with straight pipe because I ordered 2 new single chamber cherry bomb extremes should be here in a week or so.

Motor is a 360 bored 30 over ported n polished factory heads long tube headers.

 

I'd check all the obvious stuff first, plugs, wires, change the fuel filter, check the cap and rotor, personally if that don'y't fix it I would start testing/changing ignition system parts, shouldn't be flooding itself if it's dying after a few seconds, could try changing the ceramic thing on the firewall (cant think of its name, it has 2 plugs on it and is white)

 

Yeah I was gonna buy a ballast resistor on my way home from work this morning. Thanks I'll update.

 

It was the wire going to the ballast was loose and cracked up, replaced the wire and it fired right up.. Thanks for the help..