Ok, so misfire threads seem to be all the rage but I just can't find a thread where someone has the same issues. My car only misfires when it wants to and never while I'm data logging. It started about a week ago during a road trip when I tried to play with a ricer on the highway and it even died on me at 80mph. I pulled over, tried to start it and it started right up. I had one more instance of it about the time I came back.

When it died it threw a code so I plugged in the laptop and read it then, Code 33: MAP sensor voltage high, vacuum low. I took out the sensor and cleaned then plugged up any possible vacuum leaks. Afterwards I took it out for a few high speed runs while data logging and nothing happened so I assumed it was fine now.

Last sunday I went to the track, data logging the whole 120mi trip up there with no problems and ran a new best time so that really put everything to rest. Next race I didn't have the laptop going and it fell on its face again, kept me from winning my class. Of course it never happened again since I was data logging ever since then. Also when it happened I had a cloud of dark brownish fuel smoke so I think it was either something killing the spark temporarily or retarding the timing for whatever reason.

Any ideas how to test the car further?

 

I think you should monitor the fuel pressure.