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1996 mack dump truck fuel problem

rioncrsn ยท 2012-10-04 23:13

I have a 1996 rd mack and when you rev it up it start spitting and sputtering, It started off a while back but couldnt really feel the effects, but it has gotten alot worse and is killing the power of the truck, It spits out blue smoke kinda like water in fuel, but that is not the case, thanks

Replies6
  1. #1ben46a2012-10-05 08:49

    Is that an electronic or mechanical engine?

  2. #2GPC2012-10-05 18:42

    Fuel filter, injectors, injection pump. Those are all things I would look at.

  3. #3ben46a2012-10-05 19:36

    Sounds more like slipped pump timing to me.

  4. #4GPC2012-10-05 21:09

    Just wanted to add, it's kind of hard to diagnose a problem like this over the internet. This truck does have a EM6 doesn't it?

  5. #5thepumpguysc2012-10-06 08:49

    Broken overflow valve on return side of injection pump.. Its a banjo bolt w/ a spring and ball in it..Unscrew it and either shake it or push on the ball to check for a broken spring. VERY COMMON PROBLEM.

  6. #6ben46a2012-10-06 09:59

    Never thought of that, very possible. I eliminated the ofv on our pumps and put a regulator in the return.