Idle hunting is a favorite hobby of Hondas of the 1990s, but the typical hunt (normally from a bubble in the coolant) is gradual cycling between 550 and 1700 rpm. This is harsh - 3000 rpm punctuated by sharp near-stalls at about 3 second intervals. Anything that confuses the ECU will cause it, and others have reported it cleared up when they replaced the O2 sensor. In my case it was the intake manifold gasket that was in about half a dozen fragments.
Sometimes when i start my honda, whether it be cold or nice outside, just got done running or just started in the morning. It doesnt really matter what the circumstances are because its random and i havent figured out a pattern yet. It will start right up and go straight to 3000rpm's and it will go from 3000 to 900rpm's in just a short few seconds, It will continue to jump and descend in the same way until i put it in gear and start driving or i could just let it continue until it decides to stop on its own and it will do so eventually. If i drive for a few minutes straight it will go away, but i dont like shifting into a drive gear when the rpm's are high because its rough on the gears, and it has a few miles on it so id rather not have to put a tranny in it.
My 1993 Honda started revving up and down when the engine is idling, without pressing the gas pedal. This happens most often when the weather is cold. When I put it in drive and start moving, the car sounds okay, but as the car is slowed to the idling speed, it happens again. The process will keep repeating until I have driven several miles, at which point the car has warmed up, and the idling normalizes. I took the car to the mechanic who said he cleaned the EGR control solenoid. That seemed to fix the problem for a week, and then the problem came back.
WHEN I START CAR IN NEUTRAL, U HEAR ENGINE VROOM AND THEN IT COMES DOWN AND CONTINUES. NO ONE IS ON THE GAS PEDAL. ALSO WHEN DRIVING SOMETIMES IT PULLS AND THEN IT WILL START MOVING FAST ON OWN. CAR IS 5 SPEED MANUAL
A D V E R T I S E M E N T S
When sitting at light or in park, engine revs up and down until I put it in neutral or turn off.
- jmaker26, Myersville, US