How do Hondas detect misfire?

[dllewell]

Hello all,
The short story is i am wondering how the engine senses/detects a cylinder misfire.

The long story is that i have been having an intermittent no start problem with my 98 4 cyl V-tech Accord. It seems to be an ignition problem but i haven't quite nailed down what part. In testing for spark i checked each wire with a caibrated spark tester and everything checked out. Then it came to my attention that my tester was the incorrect model and i should be using the tester for high energy ignition (HEI) which has the central electrode somewhat recessed. When i tried this tester, it seemed like i was still getting decent spark but this time i also got trouble codes for cylinder misfire on 3 of the 4 cylinders.

So does the engine actually somehow measure the presence of the spark (high voltage) or does it sense some other parameter when the fuel fails to ignite (eg. pressure, temp etc.)? In other words, did the HEI tester actually show a spark failure and i just missed it?

thanks,
Dave