Results 1 to 5 of 5

Thread: Mighty Max idle issue

  1. #1

    Array
    Status
    Offline
    Join Date
    09-15-2015
    Posts
    2
    Location

    LC, RI
    Vehicle

    1989 Mitsubishi Mighty Max
    Engine

    G63B

    Mighty Max idle issue

    I just got ahold of an '89 Mighty Max with 54,000 original miles. Did a full tune up, with the exception of a fuel filter and a timing belt. The truck idles fine when i first start it but as soon as i tap the gas, it bogs down and acts like it's going to stall. I was wondering if anyone knew a solution to the problem other than raising the idle? I have considered a vacuum advance, but I want some tips before i start pulling things apart, as I'm new to these trucks.

  2. #2

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

    Richmond, CA
    Vehicle

    1989 Mitsubishi Mighty Max
    Engine

    G63B
    Try a fuel filter.
    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
    12-10-2014
    Posts
    52
    Location

    Spearfish, South Dakota
    Vehicle

    1991 Dodge Power Ram 50
    Engine

    6G72
    Also, replace the carburetor diaphragms, they are cheap. Most likely the ones on your Mikuni are dry rotted and not working correctly. Its a quick job.

  4. #4

    Array
    Status
    Offline
    Join Date
    06-15-2014
    Posts
    2,251
    Location

    Adelaide, South Australia
    Vehicle

    1985 Mitsubishi L200
    Engine

    G63B
    Take the air filter off and twist the throttle linkage - look for a squirt of fuel in the primary throat from the accelerator enrichment jet (might have to hold the choke butterfly open to get a better look). As the name suggests this gives the primary throat a booster shot of fuel when you first crack the throttle open. If it drips or just doesn't do anything the carby needs either a big clean out or a rebuild. Also try starting it with the air filter off and starving it of air by covering both primary and secondary throats with your hand. Sometimes a sudden jump in vacuum can purge junk out of the jets. The 2 main issues with the Mikuni griefing you are the automatic choke and the secondary vacuum actuator. Let us know how you go GoodApollo

  5. #5

    Array
    Status
    Offline
    Join Date
    06-15-2014
    Posts
    2,251
    Location

    Adelaide, South Australia
    Vehicle

    1985 Mitsubishi L200
    Engine

    G63B
    ^ oh the third issue occurs when some monkey takes a screwdriver to it and starts messing with adjusters and stop screws without knowing what they're doing. This can cause a level of frustration that will make you want to claw your own eyeballs out in frustration

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
  •