Hey gang,

I was desperate to solve this issue after 2 days of carlessness and joined this group in order to ask for direction. But then I realized that that's not what a boss would do. So I inspected the components inferred to be implicated and here's what I found. I wanted to share this in case someone confronts the same issue. The problem turned out to be pretty 101 but internet searches I tried didn't point me in the direction that led me to the solution.

Car: 1987 Honda Civic DX 1.5 5spd manual

I accidentally drove with the radiator cap off for about a mile and my car began to shudder. I pulled over, realized my folly, refilled the radiator and continued on to work. The sluggishness, shuddering didn't stop and the engine lacked power and smoothness until I reached around 2,800 rpms (estimated b/c no tachometer). The cause turned out to be cylinder 1 not firing (until I hit high rpms.)

After a few days of stressing, thinking and checking things I opened up the distributor cap and found that coolant, now kind of gunky, had creeped its way inside. I cleaned out the inside of the cap and used a vaccum, some tissue and a toothbrush to clean up around the rotor and near the ignition control module as well as its electrical connections. I couldn't reach into the crevices to get everything and thought about using a blow dryer to evaporate what I could but was too worried that that might damage the distributor internals or the cap's gasket. Instead I reinstalled everything and started the engine.

Voila, problem solved! I jumped for joy and am now driving my new car (new to me) again.

Final note: when I was cleaning up I suspect I moved the rotor slightly so probably need to adjust the timing or have it done. So be careful around that baby.