I have a 89 firebird with a 305 with TPI. I've had it for about a month and have had no problems. This morning I went to start it up, it started ran for about 20 seconds and stalled. Turned the key, started right up ran for about 15 seconds and stalled again. Turned the key again, started right up sounded like it was going to stall so I stepped on the gas and it didn't help. Started the last time, reved it up a few times, waited about a minute put it in gear and I was on the road. I was wondering if it might be my mass air flow sensor? Anyone know how to check them or have any ideas of what it could be?