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another u42t carb issue question

Discussion in 'Mitsubishi Minicab' started by AlaskanJeremiah, Jun 22, 2016.

  1. AlaskanJeremiah

    AlaskanJeremiah New Member


    Searching and reading through all the issues here on MTT, i have yet to find a series of issues quite like mine. any and all help would be greatly appreciated. that being said, here goes:

    I have a 94 U42T Mitsibishi Minicab. It over fueled super bad when i purchased it. it wouldn't even run. i purchased a carb rebuild kit (with the power jet needle diaphragm) and went about rebuilding the carb. upon tear down i found that the power jet was broken and in the bottom of the float bowl. i sourced a new power jet and idle jet (idle jet replaced for good measure)

    I replaced all the seals and o-rings, and proceeded to install the carb.

    the mini cab now idles AMAZING! it also is surprisingly fast at wide open throttle. the issue is i have a rather large dead spot with "part thottle".

    it straight cuts out when at part throttle. its as if someone is temporarily cutting fuel or spark. if you throttle through that, it comes back to life and it rips through the gears no problem.

    i have quadruple checked all the vacuum lines. i have ensured the fuel cut solenoid is functioning properly. i have checked the vacuum advance on the distributor and even manually controlled it with a vacuum pump.

    i have sprayed down the carb and intake manifold checking for intake leaks.

    i installed a new idle air screw and adjusted it all the way tight to all the way loose with no change in my issue.

    adjusting the choke has no effect on this issue.

    all of that being said, i am a bit frustrated and at a loss for what step to take next.

    at this point i am just hoping one of you all have experienced this exact issue (or one close to it) and can shed some light on it for me.

    Again, thank you in advance for your help!

  2. JLloyd

    JLloyd New Member

    I'm having the exact same issues,..... I'm in the middle of cleaning my carb to see if that helps
  3. Jaminxray

    Jaminxray New Member

    My brothers mitsi has been starting to do the same thing...I was warned to check the exhaust manifold for carbon buildup.. we are going to check tomorrow when we unload it.
  4. fmartin_gila

    fmartin_gila Active Member

    Check your distributor to ensure that you have constant continuity during the movement of the advance mechanism. Could be losing the ground circuit which would result in losing spark intermittently.

  5. hillltopat

    hillltopat New Member

    It may sound silly but every time I seem to have problems like that I just get a cheap bottle of gum out carburetor and injector cleaner poor in the gas tank and it seems to cure the problem for a while worth a try it'll be cheap fix it works for me
  6. warren farmer

    warren farmer New Member

    I have the same issue on a DB51T that I’ve been asking for help on but no one has offered anything substantive. Did you find out what the issue was? I really would appreciate any advice. I hit a throttle “dead spot “, then I floor it and wait for it to catch back up. It’s driving me nuts.

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