Hi, I have a 1997 honda civic 1.4I and when the engine is on but I am idle, the engine revs up and down repeatedly. It sounds as though someone is repeatedly pressing the accelarator. I wondered if you could help?
Thanks
Sarah

Might be the idle is too low and it is surging to keep going. Do you know if the idle is low? Usually set by the computer. Could be an air leak in a hose, could be a few things.

. Clean the Idle Air Control Valve (IACV):

https://www.askmehelpdesk.com/cars-t...ml#post1054149

. Clean the throttle plate and throttle body.

. Clean the air box and install a new air filter.