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V6 Mechanical Fuel Pump

Discussion in 'Early CJ5 and CJ6 Tech' started by Mojave, Apr 10, 2006.

  1. Mojave

    Mojave Member

    The mechanical fuel pump has gone out on our 66 V6 CJ6, and we’re temporarily running a noisy Purolator electric. For some reason, we’re having difficulty locating a replacement pump locally. At several online parts houses, I notice they list a different pump for the “65-66” Jeep V6, than for the 67-71. Anyone know why? Are there any plain old Buick V6 pumps, like maybe from a 66 LeSabre that will fit and work?
     
  2. sparky

    sparky Sandgroper Staff Member Founder

    Won't be a Buick that used the V6 of the same age. Kaiser owned the engine.

    Umm, is there a return line difference or something? What about a 65-66 Buick 350?
     
  3. jpflat2a

    jpflat2a what's that noise?

    the AC/Jeep p/n for no return is 6414989 (1965-1966)
    the AC/Jeep p/n for return line is 6416783( 1967-1971)
    maybe they can cross these AC numbers for you
     
  4. Mojave

    Mojave Member

    Thanks for the quick replies - I was under the impression that Kaiser was licencing the 225 Dauntless V6 from Buick, and that the one in the LeSabre was pretty much the same. What's the function of the return line? The pump that came with the Jeep doesn't have one - but the code on the Rochester carb indicates that it's a later model Jeep carb - like a 71 if I recollect correctly. Could the use of the newer pump be related to the carb?
     
  5. jpflat2a

    jpflat2a what's that noise?

    in theory, the return line would "return" or recirculate the unused fuel back to the tank, which had an extra nipple on the sending unit for this purpose.
    In theory, it helped to reduce the possibility of vapor lock and hot soak conditions.
    In reality, it creates more fuel lines and possible sources of fuel leaks.
    In my opinion, I would run a pump w/o the return line option.
    Just makes life easier.
     
  6. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Re licensing the V6, AFAIK Kaiser bought the tooling and design outright from GM, then AMC sold it back when GM wanted it back. No licensing... purchase.
     
  7. Mojave

    Mojave Member

    Thanks - I think we will run it without a return loop, as the tanks aren't fitted for it. If Kaiser bought the design outright, what kind of V6 did the 66 LeSabre run? Maybe Buick licenced from Kaiser??
     
  8. lynn

    lynn Time machine / Early CJ5 HR Rep Staff Member

    IIRC, Buick had a stockpile of blocks/components in the pipeline when the tooling was sold to Kaiser... so naturally Buick used up their remaining inventory.