Started up my '73 FJ over the weekend and drove 5 minutes away to a gas station. Seemed to crank more than usual to start after filling up. Drove another 5 minutes and shut it off. Then I started it again which required even more cranking. Then drove it about 30 minutes, it rain fine. Got to my destination and it wouldn't start. While stranded, I swapped out the coil for a brand new one and nothing. Had to get towed home. The next day I put the original coil back in and it fired right up. Anyone know what's going on here?