This is strange as it doesnt happen all the time, ok, the car has the 3.0 vulcan, runs great, but sometimes when cruising along, the thing starts bucking and jerking really hard, acts pretty much like either the fuel supply is coming and going or the ignition is cutting out, i was on the way home from the store and it started the bucking and it quit, i threw it into neutral, fired it back up and kept going, turmed the corner and took off normally, started doing it really bad and quit, i threw it into neutral again and cranked and cranked and it would not restart, i coasted as far as i could and pulled over and cranked some more, nothing, finally i cranked it one more time and it fired right up, so i took off again and it did fine all the rest of the way home except for one time, i put it to the floor and it hit the passing gear and was winding up and it bucked a couple times, but didnt quit. Like i said, it doesnt always do it and i dont know how to diagnose this, i cant really afford to take it to a shop and since it doesnt do it all the time i dont think a shop would have much luck finding the problem, there are no codes or anything. Dont know what to start replacing first, thought maybe the pickup coil or the ignition module maybe, but i dont know if its fuel or ignition.? HELP!!