Okay...problem happened yesterday. I drove for about an hour or so. It was kind of hot. Well, stopped at a wal-mart to buy something and left. Car started fine as i left the lot. Drove for another 10-15 minutes and stopped to buy a newspaper. Shut the engine off and went. When i came back, i started the engine fine, but then it shut off in like 2 seconds. I restarted it and it kept cranking and the check oil light came on. I tried one more time and it started fine. I'm thnking maybe it might be the starter...but then its kind of odd because it started just fine earlier that day. I changed the oil about 400 miles ago. The battery is about 2-3 months old. I had a previous thread about my reverse problem and the motor jumping as well. Can a busted mount be the problem as well? the motor does jump while it starts...thanks in advance to anyone who can help

Car: 1991 EX F22A1, 263k Miles.