Results 1 to 14 of 14

Thread: Revving on its own

  1. #1
    Senior Member kawasakirob's Avatar
    Join Date
    Apr 2009
    Location
    Grand Rapids, Mi
    Posts
    1,684

    Revving on its own

    I drive a 2001 Hyundai Accent with 257k miles. It started revving on its own just recently. It has a manual transmission and has been running just fine until now.

    I've been told to check the airbox, the vacuum hose connecting to the airbox (for cracks) and the spark plugs. I've also been told to add some additives to the fuel in order to clean the injectors.

    What do you guys think?
    www.chuckdavisrestorations.com


    Go Crutchlow #35

    Go Hayden #69

    Go Stoner #27 "The Absolute Intercontinental Ballistic Missile of MotoGP!"

    Go Sykes #66 2013 WSBK Champion. Go Green!

  2. #2
    Gold Member Zach929rr's Avatar
    Join Date
    Mar 2009
    Location
    Bullying Chatfield Kids
    Posts
    5,716

    Re: Revving on its own

    Checking for vacuum leaks and cleaning the MAP/MAF is a good start.

    My explorer would do this when the MAF got dirty thanks to the head ventilation dumping into the intake tube pre-MAF.
    KX65
    Dizzer
    929 - Yard Sale'd

  3. #3
    Gold Member asp_125's Avatar
    Join Date
    Jan 2004
    Location
    BoCo
    Posts
    6,532

    Re: Revving on its own

    Need more info. Revs go up while idling? Revs drop (like it wants to stall)? While in gear? While under load? Clutch slippage?

    I'd suspect vacuum leak, too.
    When life throws you curves, aim for the apex
    Current stable:09 Thruxton \ 09 FZ6S2
    Sold List:97 Ninja500R, 03 SV650K3, 01 Ducati 750Sport, 73 CB350/4, 03 F650GSA, 08 Gixxer600, 03 Gixxer600, 91 VFR750F, 09 KLX250, 06 Thruxton 900, 02 VFR800, 08 Spyder RS, 12 Street TripleR, 09 KLX250S, 16 KTMRC390, 10 F650GS
    my Facebook, SpeedShots
    Quote Originally Posted by salsashark View Post
    ... Motorcycles are kind of like Baskin Robbins... You're looking at 31 flavors of ice cream, don't you kind of want to know what they all taste like?...

  4. #4
    Senior Member kawasakirob's Avatar
    Join Date
    Apr 2009
    Location
    Grand Rapids, Mi
    Posts
    1,684

    Re: Revving on its own

    Quote Originally Posted by asp_125 View Post
    Need more info. Revs go up while idling? Revs drop (like it wants to stall)? While in gear? While under load? Clutch slippage?

    I'd suspect vacuum leak, too.
    All the time. Idling, clutch in or out.

    Quote Originally Posted by Zach929rr View Post
    Checking for vacuum leaks and cleaning the MAP/MAF is a good start.

    My explorer would do this when the MAF got dirty thanks to the head ventilation dumping into the intake tube pre-MAF.
    What's the MAF?
    www.chuckdavisrestorations.com


    Go Crutchlow #35

    Go Hayden #69

    Go Stoner #27 "The Absolute Intercontinental Ballistic Missile of MotoGP!"

    Go Sykes #66 2013 WSBK Champion. Go Green!

  5. #5
    Gold Member Zach929rr's Avatar
    Join Date
    Mar 2009
    Location
    Bullying Chatfield Kids
    Posts
    5,716

    Re: Revving on its own

    Mass Airflow Sensor.

    KX65
    Dizzer
    929 - Yard Sale'd

  6. #6
    Gold Member madvlad's Avatar
    Join Date
    Sep 2007
    Location
    St Petersburg, FL
    Posts
    10,363

    Re: Revving on its own

    When you drive it does it act up at all?
    www.mo-door.com
    https://64degreeracing.com/

    2003 VFR800
    2007 GSX-R600
    2007 R1
    2003 R6 Race bike
    2010 Ducati SF1098
    2016 60th R1
    2018 Aprilia Tuono V4 1100RR (Always say I'm done riding but the results state that I lied... )

  7. #7
    Senior Member kawasakirob's Avatar
    Join Date
    Apr 2009
    Location
    Grand Rapids, Mi
    Posts
    1,684

    Re: Revving on its own

    No not really. Just wants to keep revving
    www.chuckdavisrestorations.com


    Go Crutchlow #35

    Go Hayden #69

    Go Stoner #27 "The Absolute Intercontinental Ballistic Missile of MotoGP!"

    Go Sykes #66 2013 WSBK Champion. Go Green!

  8. #8
    Member jcj81's Avatar
    Join Date
    Aug 2012
    Location
    Longmont
    Posts
    206

    Re: Revving on its own

    Its sounds like a vacuum leak issue, but first make sure throttle isn't sticking. If it is a vacuum leak it usually would have to be a large leak to cause engine to rev, are you able to hear a leak, air being sucked in? Check the hose coming off the brake booster thats usually the largest vacuum hose. What rpm does it idle at?

    It could also be the idle control valve possibly sticking with that mileage carbon could cause it to stick.
    Last edited by jcj81; Wed Apr 24th, 2013 at 06:10 PM.

  9. #9
    Senior Member kawasakirob's Avatar
    Join Date
    Apr 2009
    Location
    Grand Rapids, Mi
    Posts
    1,684

    Re: Revving on its own

    At idle: 500-3k
    But if I'm driving and push in the clutch at 3k it'll rev higher.

    Also getting on/off the gas is pretty jerky. I put some BG400k in the tank to see if it improves while I do some driving tomorrow. I will check for air in the vacuum hose and get back with you guys.
    www.chuckdavisrestorations.com


    Go Crutchlow #35

    Go Hayden #69

    Go Stoner #27 "The Absolute Intercontinental Ballistic Missile of MotoGP!"

    Go Sykes #66 2013 WSBK Champion. Go Green!

  10. #10

    Re: Revving on its own

    OP, throw a youtube video up...

  11. #11
    Senior Member matt2778's Avatar
    Join Date
    Jul 2007
    Location
    The slow guy in the back
    Posts
    535

    Re: Revving on its own

    Does it hunt or just rev up?
    If You Can't Ride It or Take it to Bed. It Ain't Worth Having!

  12. #12
    Gold Member madvlad's Avatar
    Join Date
    Sep 2007
    Location
    St Petersburg, FL
    Posts
    10,363

    Re: Revving on its own

    Quote Originally Posted by jcj81 View Post
    Its sounds like a vacuum leak issue, but first make sure throttle isn't sticking. If it is a vacuum leak it usually would have to be a large leak to cause engine to rev, are you able to hear a leak, air being sucked in? Check the hose coming off the brake booster thats usually the largest vacuum hose. What rpm does it idle at?

    It could also be the idle control valve possibly sticking with that mileage carbon could cause it to stick.
    I'm thinking the idle control valve but then if the revs differ since he posted 500 to 3k that's kind of a huge jump, sounds more to me like it's idle surging.
    www.mo-door.com
    https://64degreeracing.com/

    2003 VFR800
    2007 GSX-R600
    2007 R1
    2003 R6 Race bike
    2010 Ducati SF1098
    2016 60th R1
    2018 Aprilia Tuono V4 1100RR (Always say I'm done riding but the results state that I lied... )

  13. #13
    Member
    Join Date
    Jun 2007
    Posts
    149

    Re: Revving on its own

    Disconnect the MAF sensor and see what it does. It should go to limp mode. If it levels out, then carefully clean the connector and very, very carefully clean the MAF sensor.

  14. #14
    Gold Member Kim-n-Dean's Avatar
    Join Date
    Aug 2003
    Location
    Aurora
    Posts
    5,609

    Re: Revving on its own

    Throttle Position Sensor.
    Kim & Dean
    60th Anniversary R6 - '16 R1M


    .

Similar Threads

  1. Highest revving motorcycle?
    By Mental in forum Non-Bike Discussion
    Replies: 6
    Last Post: Tue Feb 17th, 2009, 05:09 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •