ok i have a 1978 buick regal, 350, 2barrel. choke works fine. car starts and drives great but every once in a while it just refuses to start. i drove to the post office one day, came back out and it wouldnt start. getting gas, choke was working fine, spark good, everything. just wouldnt turn over. after about a minute of just holding the key in the start position, it finally came to life. went to the gas station, and parked it. turned it off, and tried again and it fired right up. no problem and that was less than a minute later. it does this every now and then. starts and drives fine, then it refuses to start for anywhere to a minute to a few hours, then starts like a charm again? ive done all kinds of trouble shooting and just cant figure it out. i dont wanna have to worry about being stranded somewhere.