Apple395

I have a 2000 Civic EX Manual (160k Miles)

It has a weird problem that I cant pin down...

My car has a very picky misfire on cylinder 1 (P0301)

My car starts and runs great when warm*, or when cold

BUT when it is semi warm (sitting for over 15 mins, but less than 1 hr)
It WILL misfire... if i push it to 3k (if a baby it to like 1500 it will pass its window of in between temps and not miss)

I gave it a full tune up (wires,plugs,rotor,cap,air filter,oil)

I am stumped, any ideas will be VERY appreciated.

instrument

iif youve got it down to a cylinder, could be the injector. recently i've had some issues with one cylinder, cleaned the injector and the plug and its magically been fine this whole week.

Mr. Bojangles

Could also be the ignition coil. I had the same exact problem a few months back and a new coil fixed it. Try and see if you can borrow someone's coil though before you buy new one.

DumpdEJ6

Check the fuel rail. I had a diagnostic nightmare of a time with my B16 once, with a very erratic misfire in only one cylinder. Turned out to be the injector filter where the injector pushes into the fuel rail. It popped off and wedged itself sideways in the rail and starved that cylinder occasionally.