My 1998 Honda Civic has been misfiring when I start it in the morning. It lasts for 5-10 seconds after which the engine light comes on. The error code tells me it is cylinder 1 misfiring. What I’ve tried so far: (1) new spark plugs (2) new spark wires (3) new distributor cap and rotot (4) new distributor (5) replaced the vtec solenoid. Compression check is fine. Fumes show good combustion. What could be going on? I wouldn’t be too worried where it not that the engine light every time comes on. Ideas?
You have taken care of the most probable causes, I think it may not be fuel injected meaning it might be a choke problem. So the too rich formula is causing the error code.
You could swap #1 fuel injector with another position (say #3). If the misfire goes to the other position…
Many people often post here with the comment that compression is fine and often that word is not quite appropriate when the actual figure is known.
What is the compression number you have?
My 99 Civic did something similar, but sometimes long enough that I could listen to each injector through a stethoscope. One was not clicking. Later I was at a parts place pricing new injectors (way too much) and a customer gave me a suggestion that had worked for him on his truck. I went home and tried it: I started the engine, and it idled roughly. I tapped the bad injector with the handle of a screwdriver a couple times. The engine smoothed out and that injector worked and felt and sounded just like the others. I unplugged and plugged back in the electrical connector to each injector - each turned off and came right back on. I put a can of Sea Foam in the gas tank. The problem has not come back.