so i had the little racecar out to the track today (circle track, its a full-on mini-stock car)

and it will run up to about 6000 rpm, then just shut off and die, almost like it is running out of fuel, but then come right back on. but its not consistent with 6000 rpm, sometimes it goes at 6500, sometimes 5500, sometimes lower.

my car is a 1993 with a 1.6L in it. it originally had a 1.5L in it, with the MAP on the firewall.I was running with theMAP on the manifold, and it runs good everywhere, when i came off the track, i decided I'd try to run it with the MAP on the fire wall. that fixed a problemfor a little bit, and it ran pretty decent. but about every ten laps, the car would shut down, and if i were to floor it, it will rev up for 4000 rpm, and not any higher, sort-of like a "rev limiter."

once i came back into the pits,I switchedback to the MAP on the manifold, and the car is running rich, and belching a little black smoke.

could this me a MAP or O2 sensor going bad? or would this mroe likely be a computer problem?

its arace car, so it does have any check engine lights, so it obviously not showing me any codes.

thanks.