surging engine at 2500 rpm and above on 1991 Honda Civic

When the gas peddle is depressed to about 2500 rpm's the engine has a bad surge, it is consistant surge fron 5oo rpm to 3000 rpm , back and forth. any ideas

Asked by for the 1991 Honda Civic
There are many different engine options on the Civic that year. Oxygen Sensor that is failing can be responsible for surging problems. With the engine switched off disconnect the EGR valve and see if the surging goes away if it does the EGR Valve may be faulty or the EGR passages may be partially plugged allowing EGR into one cylinder only. Need to know what engine and how many miles do you have on your car. When were the valves last adjusted?
We have a 2001 honda odyssey that is doing the same surging thing. Will do it at 5000 in neutral. Has 180,000 miles on it. Never had valves adjusted. Does that year and make have a EGR valve? I replaced the air filter and it did not help. Since I am on someone else's question, don't know if you can reply to me. My email is Thanks, Terry
1 more answer
it is the air control valve or the air control sensor