1990 Accord surges when the engine is in the mid-range of warming up. Warm it runs just fine. I have replaced the O2 sensor and the eicv valve. I am frustrated and would really like to settle the engine down. Any other ideas to look into?

i forgot when honda stopped putting cabrs into accords, so is this carb or inject?

I assume you don't get a Check Engine light, or else you would have told us. Another possibility might be the ERG valves.

it might be your IAC <Idle air control>, or your IAT <Intake air temp sensor>. i've seen my fair share of problems with both.

it might be your IAC <Idle air control>, or your IAT <Intake air temp sensor>. i've seen my fair share of problems with both.

Yup, agreed, but make sure the coolant is full too. A little low, and it starts surging against the temp sensor after the thermostat starts to open, making the idle surge up and down with it...

Thanks. The car is injected and the coolant was one of the first items I looked at. Not the problem. I will look into some of the other suggestions.

ERG valves
Sorry - typo - s/b EGR valves

mine is doing the same, someone told me that it was the tps (throttle positioning sensor)... well, that sensor is rivited onto the throttle body on my motor (d16z6).. the only way i could change mine is a new throttle body or drill and re-rivit

I don't believe it is the TPS unless it is surging all the time. And I have found that the TPS isn't always at fault, sometimes it is the linkage connected to the TPS. This linkage is located inside the housing. I have gotten lucky and been able to lubricate the linkage and resolved the problem. However, with my system it surges only after it drops from the initial high idle of cold to that period until warm. Once it hits the warmed up state, the engine idles perfectly.