revs while idling

Discussion in 'General Motoring' started by Matt Roos, Feb 21, 2004.

  1. Matt Roos

    Matt Roos Guest

    Hi, All. I have a '94 Accord. When in park and idling, the engine revs up
    and down with about once per second. rrrrrRRRRRRrrrrrrRRRRRRrrrrrrrRRRRRRR.
    etc. Can't remember the RPMs, but at the peak, it's probably double the
    normal idle RPMs.

    What could the problem be?

    Matt Roos, Feb 21, 2004
  2. Matt Roos

    Eric Guest

    This problem is often due to either low coolant, lack of coolant circulation
    through certain valves/sensors, or trapped air in the coolant system.

    You might want to read some of the prior threads where this problem has been
    discussed before, for example

    Eric, Feb 22, 2004
  3. Matt Roos

    DGB Guest

    Approx 3 weeks after changing the head gasket on my wife's '95 Civic, I also
    had this problem and discovered that there is what appears to be vacuum line
    attachment assembly (about 2.5 x 4 inches) behind the fuel intake (top of
    engine, center, near the fire wall). Two 10mm bolts had backed out and was
    causing this. 5 minutes later everything was good again.

    hope this helps.
    DGB, Feb 22, 2004
  4. Matt Roos

    DGB Guest

    Approx 3 weeks after changing the head gasket on my wife's '95 Civic I had
    this problem develop as well. I discovered that the two 10mm bolts holding
    the IAC (Idle Air Control) Valve on had backed out. 5 minutes later all was
    good again. Oh yeah, this thing is located top center near the fire wall on
    the air/fuel intake assembly. It's about 3 x 4.5 inches...

    hope this helps...
    DGB, Feb 22, 2004
  5. Matt Roos

    icebox Guest

    I second that idea about low coolant. My 97 accord did the same after
    it lost all the coolant due to a leak in the Radiator.
    icebox, Feb 23, 2004
  6. Matt Roos

    Dan Guest

    I also have a '94 Accord EX Coupe 2.2vtec. Mine revs for about 10min before
    it gets warmed up. And also if I give it gas just after starting it up on a
    cold day it revs up then goes down to about 900 and back up to about 1500
    really fast. Is that what you mean? Also, I have a question for you......How
    warm does your heat get?
    Dan, Feb 27, 2004
  7. Matt Roos

    Denise Craig Guest

    I'd also check the EGR valve

    Denise Craig, Mar 3, 2004
  8. Matt Roos

    HyDr0 Guest

    you know icould also be a faulty o2 sensor. it happened to my car. high low
    surging so i went to the garage of a friend of mine
    tested my sensors and everything my o2 sensor was shot so i replaced it and
    i havent had a problem since

    HyDr0, Mar 6, 2004
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