Results 1 to 10 of 10

Thread: Strange speedometer increase without RPM increase

  1. #1

    Array
    Status
    Offline
    Join Date
    12-18-2014
    Posts
    215
    Location

    Vancouver, WA
    Vehicle

    1984 Mitsubishi Mighty Max
    Engine

    G54B

    Strange speedometer increase without RPM increase

    Seemingly random while driving 40 ~ 50 mph the speedometer will occasionally jump up about 5mph and settle back down without the RPMs increasing along with what the speedometer is reading. Not tachometer, the speedometer. No stepping on the gas to go faster or taking foot off the gas to slow down, just while holding it steady cruising along.

    If it was tachometer I'd think maybe the ECU (as I had that issue on the '93 mitsu I have) but I have no clue what could be causing this. Is this an automatic transmission related issue? Or is there a sensor or cable or something I should check? Really lost! Admit it's only been about 2 hours total of driving time so far since I got it so not sure if it always does this or not.

    I can't find anything about this in the book & forum searches only gave me more things to do on other lists, lol.

    Anyone have this happen before? What was it? Or could it be?

    Wasn't sure what topic to put this in, hope it's okay here, thank you.

  2. #2

    Array
    Status
    Offline
    Join Date
    08-11-2012
    Posts
    1,199
    Location

    Richmond, CA
    Vehicle

    1989 Mitsubishi Mighty Max
    Engine

    G63B
    Diagnosis: Mitsubishi.

    The truck, like Herbie the Love Bug but more costly, is telling you how fast it wants to go, but can't at the moment, because something will break.

    Check the fittings at both ends for snugness? Maybe the worm gear is getting worn or is slipping.
    I can help get your truck to pass California smog! PM me.
    California BAR Smog Inspector License #EO635469
    "Keep 'em on the road."

    See what I have for sale:
    http://stores.ebay.com/zims

  3. #3


    Array
    Status
    Offline
    Join Date
    01-16-2014
    Posts
    470
    Location

    Las Vegas, NV
    Vehicle

    1991 Mitsubishi Mighty Max
    Engine

    4G64
    Speedo cable is most likely worn out or the actual gearing in the cluster for the speedo is worn.

    Mine does the same thing... it's not a big deal that it does it unless you really have no clue how fast you're going.

  4. #4

    Array
    Status
    Offline
    Join Date
    04-09-2014
    Posts
    595
    Location

    sheffield, vt
    Vehicle

    1978 Dodge D-50
    Engine

    G63B
    i would try the easy/cheap attempt: disconnect the cable from back of the instrument cluster (all work can be done from the driver's seat) & spray a decent volume of graphite lube (ie: http://www.amazon.com/Blaster-8-GS-G...2M9WMK58K5YN3A ) down the inside of the spedo cable....not to be confused with this spedo

  5. #5



    Array
    Status
    Offline
    Join Date
    03-20-2011
    Posts
    4,113
    Location

    Pittsburgh, PA
    Vehicle

    1980 Dodge D-50
    Engine

    G54B
    I second lubing the speedo cable - if they bind it will start to cause fluctuations - if left go long enough, the cable will break.
    Pennyman1
    The best Dodge that Dodge never made
    Living the D-50 lifestyle since 1980

  6. #6

    Array
    Status
    Offline
    Join Date
    04-09-2014
    Posts
    595
    Location

    sheffield, vt
    Vehicle

    1978 Dodge D-50
    Engine

    G63B
    & if it breaks...it may take a little effort to find "This product is no longer available": http://www.factorychryslerparts.com/.../MB113869.html

  7. #7



    Array
    Status
    Offline
    Join Date
    07-24-2012
    Posts
    2,357
    Location

    Washington State
    Vehicle

    1986 Mitsubishi Mighty Max
    Engine

    G63B
    Is that picture up there hurting anyone else's eyes besides mine? or maybe I just spilled chlorine in them.

    Reminds me of Ben Stiller in the movie Dodge Ball.
    Name:  ben.jpg
Views: 173
Size:  25.1 KB

  8. #8

    Array
    Status
    Offline
    Join Date
    08-11-2012
    Posts
    1,199
    Location

    Richmond, CA
    Vehicle

    1989 Mitsubishi Mighty Max
    Engine

    G63B
    Quote Originally Posted by ragragtimetime View Post
    not to be confused with this spedo
    I believe this is technically a singlet, not a speedo.
    I can help get your truck to pass California smog! PM me.
    California BAR Smog Inspector License #EO635469
    "Keep 'em on the road."

    See what I have for sale:
    http://stores.ebay.com/zims

  9. #9

    Array
    Status
    Offline
    Join Date
    12-18-2014
    Posts
    215
    Location

    Vancouver, WA
    Vehicle

    1984 Mitsubishi Mighty Max
    Engine

    G54B
    Luckily I can't see the pic, just a box with a camera and a circle/line over it

    But I will go ahead and spread around some graphite & see how that helps. Wouldn't you know it, this morning I didn't catch it moving itself up! The e-brake was kind of sticky, too, for the first day of driving/parking, so may as well use graphite, oil, or lube everything I can find. Already did the bottom of the truck, time for inside I see. Thank you for the ideas!!! Yeah, a broken one would be terrible!!!

    and Noah: "Diagnosis: Mitsubishi." roflmao I'm going to have to remember that one! Darn truck, lol.

  10. #10

    Array
    Status
    Offline
    Join Date
    08-11-2012
    Posts
    1,199
    Location

    Richmond, CA
    Vehicle

    1989 Mitsubishi Mighty Max
    Engine

    G63B
    Quote Originally Posted by tink View Post
    Noah: "Diagnosis: Mitsubishi." roflmao I'm going to have to remember that one! Darn truck, lol.
    They're shitboxes, but they're our shitboxes.
    I can help get your truck to pass California smog! PM me.
    California BAR Smog Inspector License #EO635469
    "Keep 'em on the road."

    See what I have for sale:
    http://stores.ebay.com/zims

Tags for this Thread

Bookmarks

Bookmarks

Posting Permissions

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