1998 cummins 8.3 won't run properly

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by ThatGuy72, Dec 15, 2018.

  1. ThatGuy72

    ThatGuy72 Bobtail Member

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    Dec 15, 2018
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    I have a '98 FL70 reefer with a Cummins 8.3 i am trying to bring back to life. I got it running after sitting for 7 years. I have replaced fluid and filters...New diesel. It would run and rev through the RPM range but lacked power at higher RPMs...put seafoam in the tank and it seemed to run better....Smoked like a chimney....the motor will cold start...idle fine....and warm up to operating temp however now if you apply the throttle it revs up rough to about 2k then dies and becomes hard to start? its like its dumping too much fuel in the bores??? help?
     
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  3. stillwurkin

    stillwurkin Road Train Member

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    Dec 2, 2017
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    So many things. Did you put fresh fuel in tank(s)? Did you pull off primary fuel filter? After it quits running. Is it almost full of fuel, is fuel in it dirty? Did you check air filter box..could be a mouse mansion. Have fun.
     
  4. BoxCarKidd

    BoxCarKidd Road Train Member

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    Aug 26, 2014
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    A 98 is almost old enough for me to be able to fix something. If you follow the fuel line from the tank to the engine does it go to a small manifold housing thing about 3 inches in diameter? Take it apart and clean out the screen.
     
  5. jake744

    jake744 Light Load Member

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    Dec 27, 2017
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    Is it a p-pump or caps pump engine. P-pump injector lines are in a straight line,caps pump are rotary or in a circle?
     
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