so heres the story. couple months ago i was driving along and an engine mount bolt snapped in half, got wedged against my timing belt until it wore through and my timing belt broke. bent all my exhaust valves.

I pulled the head off, bought new valves, lapped them in and installed them. I'll admit, the exhaust valve guides had a bit more slop than i would have liked, but this is my daily rider, and i am impatient. reassembled the car and it fired up. drove great, just like it had before.

around 1000 miles later, I start getting a stumble. the sound kind of reminded me of when a 2 stroke engine is "4 stroking". (typically the air fuel ratio is off and so it takes 4 strokes to get enough gas in the chamber to fire instead of 2, youtube it). i thought (hoped) that it was just the timing being slightly off after the new belt and the head coming off. so i found the service connector plug and reset my timing. no change.

the stumbling has been getting progressively worse, the car finally spit out a check engine light with the error code 73 - random misfire, cylinder 3.

I'm guessing its my valve guides and exhaust valves again causing low compression, but I was wondering if anyone had any other suggestions i can try? or something i can check that may have gotten "off" over the course of broken timing belt and repair.

EDIT: sorry, i forgot to mention that it gets worse as the car warms up. it almost doesnt happen on a cold start. also, it's worse under load. whether i give it gas to accelerate or if i'm trying to get up a hill in 4th (automatic) doing 60, i'll have a hard time, but i can downshift to third and make it. finally, i'm a bit embarrassed to say, my muffler is not on the car. it rusted off a couple months ago right before the belt broke and i just haven't had the time to weld it back on.