Love hate relationship with my Mack.

Discussion in 'Mack Forum' started by ChicagoJohn, Aug 10, 2016.

  1. ChicagoJohn

    ChicagoJohn Road Train Member

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    I have an 08 Pinnacle with the MP8. I broke down in OH Monday and finally got the call from the Mack dealer that I need all 6 injectors. I'm being told that I have an older style injector with copper tips and cups. I guess 2 of the cups are cracked and all the injectors are in horrible shape. For 8 months I have been getting horrible fuel economy and almost no power.

    The shop is replacing the injectors with conical injectors. From my understanding, I should see a huge improvement in power and fuel economy.

    Can anyone explain the difference between the injectors? From what I understand, the conical injectors are a complete unit?
     
  2. Sharky88

    Sharky88 Heavy Load Member

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    Volvo/Mack used copper cups for the injectors for several years they had problems with the dissimilar metals that caused the cups to fail. The new cups are steel and are stronger. The conical shape creates a better fit between the injector and the head. You should get better power after the fix
     
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  3. ChicagoJohn

    ChicagoJohn Road Train Member

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    I really hope so. At this point a any mile long grade makes me downshift and heeded to Omaha, there's a few hills I have to drop from 13 to 10th.
     
  4. Sharky88

    Sharky88 Heavy Load Member

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    You probably weren't having fuel injected properly in the cylinder and with the cups leaking not enough compression to properly burn the fuel. You will notice a difference
     
  5. sawmill

    sawmill Road Train Member

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    Place I used to work had four macks. They weren't bad trucks except for those injector cups. Seems like the '08 we had it was a repair that we had to do several times. The three '07s were mostly trouble free.

    Driving a Mack is like having a sister that works in a whorehouse. Might be part of life, but you have to be careful not to talk about it in front of people.
     
  6. QUALITYTRUCK

    QUALITYTRUCK Road Train Member

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    After replacing them you are going to love your truck again.................until the next time it happens unfortunately!
     
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  7. ChicagoJohn

    ChicagoJohn Road Train Member

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    I was told since the conical injectors are one piece, I should have anymore injector issues. At least not the same problem with the copper cups. I was planning on getting rid of the truck, but it this point I have new clutch, clutch cable, rebuilt trans, radiator, AC condenser, turbo, fuel pump, power steering pump, power steering cooler, shocks, tie rods, dpf delete, and numerous other smaller items........i might just have to keep it.

    It's like buying a glider, one part at a time.
     
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  8. sawmill

    sawmill Road Train Member

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    Sounds like a Johnny Cash song
     
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  9. ChicagoJohn

    ChicagoJohn Road Train Member

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    I was doing the math in my head. Over the last year since I bought this truck, I have spent almost as much in repairs as I paid for the truck. Difference being, I was able to finance the truck purchase. :eek:
     
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  10. ChicagoJohn

    ChicagoJohn Road Train Member

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    I can not believe the difference in power. I had 3 mechanics tell my they were amazed that I got 800,000 out of the old copper lined cops & injectors.