After reading that I just remember like back in December one morning about 30 degrees i went to crank mine and it would not crank, well it cranked and ran for maybe 2 minutes then cut off, i went to crank back up and nothing, i ended up running the battery down trying to crank it, it would hit then nothing we used a neighbors truck to hook up jumper cables and used starting fuild to try crank it, it would run with spraying the starting fuild in it and then it die soon that ran out. Well I ended up charging up the battery all day then trying again about 4pm that afternoon by then it was maybe 45 degrees ( it was a cold ga day) well after maybe 45 minutes of having it crank die, crank die, I finally got it to crank and held the gas pedal down had it up to like 2,000 RPMS and held it there for minute straight, it was running really crappy spitting and spurdering then all of sudden something like POOF and some smoke came out of the exhust and it went to running smooth.. well ive not had any issues with is since then, Not sure what it was but my buddy said a piece of carbon could had been clogged in the cat. and could had finally blown out of it.
it is strange when one will crank and run then won't, maybe your having whatever issue i was having. i had to keep pressing the gas pedal and keep cranking on it, i was worried i wear out the starter doing it so much.