hey guys, havent been on here in a while. engine is b16a2 in 1999 si. stock em. before i put my car away for the winter last year i had an intermittent missfire on cycl. 3. when i came off the high way i actually thought the car was going to quit, (not aggressivley driving as this has been happening for a while, so i limp it most of the time) and i had to keep on the gas. when i got home the car sounded like a subaru, that deep throaty rumble and the engine shook pretty good. i knew missfire and confirmed it with a code and went to purchase new wires, plugs, rotor and cap. same issue so i did a comp check and all exept cycl. 3 were good 185-190. cycl 3 was low, 135? (this was last year, but i know it was low), so i maybe figured that the missfire caused unburnt fuel to wash the oil off the walls giving a false reading. i did the check again when i knew it wasnt missfiring, and it was still low, but not as bad (170ish). now this year i still have cel and it does blink indicating missfire on same cycl 3. during the major missfire i checked plugs and cycl 3 was black and wet, oil i figured, and at any other time it had major ashy/carbon deposits on it compared to the other 3. now after all this my idea is that the ring lands are broken and the pieces are floating around the piston and occasionally making a better seal at times then others. sorry so long but i want to give the whole story.....any ideas

 

have you done a leakdown test?

 

no leakdown test, one of the pieces of equipment i dont have. i had planned on going into the motor anyway, was just wondering if any one had pretty close idea to the problem.

 

It's probably worth paying a shop 50 bucks or whatever to do a leakdown test. That way, when you open up the motor you will already know what the problem is.