my car hasn't been driven for about 2 months. i drove it to portsmouth the other day and it has developed a starting problem when hot.

when i started it, it sounded like it was firing on 3 cylinders and it idled at around 500rpm. when revved it was backfiring and generally sounded sh*t i had to keep starting it until it fired up properley and idled at 1000rpm and was smooth.

then after getting it started properly, it developed a misfire on full throttle. at one point flat out in third, it was as if it hit a rev limiter @ 4000rpm and all i got was popping from the exhaust and it wouldn't go any faster

any ideas?