I searched and didn't find a good match. My 90 Accord EX (175,000 mi) usually runs absolutely super - great power throughout RPMs, idles smooth at 750 RPMs, starts good, etc. Suddenly three days ago, while going up a hill, it started to buck as if in two high a gear. I downshifted and finished up the hill but with less power than usual. Now it idles rough almost to a stall and doesn't get good power until up around 3000 RPM. The chech engine light never came on so I haven't checked to see if a code is set. I've never cleaned the injectors or replaced rotor or wires. But this came on so suddenly I am assuming that it is one particular thing that is failing.

I had to check for codes on this vehicle a year ago so I know how to do it. The check engine light had come on that time and it turned out to be the EGR valve stuck. This time no check engine light and other lights and gauges on the dash are all OK. Any Ideas? Sorry this is so long.

 

Will there be an ECU code set if no check engine light?

 

Going home now to check the ECU code (if any) and EGR to see if it is stuck. Will post back tomorrow.

Thanks!

 

There was no ECU code. When I pulled the number 1 spark plug the gap was completely closed. I regapped the plug, replaced it and the engine purrs again. My only concern is what closed that gap. My guess is a small piece on the edge of a valve broke and was positioned exactly below the spark plug when the piston came up. I'm hoping whatever was in that cylinder is either stuck to the top of the piston or went out through the exhaust valve. Anyone ever experience anyting like this?