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'94 IDIT runs rough, low power, nearly overheating after Moose IP

Discussion in '6.9L IH & 7.3L IDI Diesels' started by SLC97SR5, Sep 11, 2019.

  1. SLC97SR5

    SLC97SR5 Full Access Member

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    My Truck in my signature is experiencing some strange issues.

    I have been experiencing rough idle, low power and oil consumption.

    Years ago I swapped out the OEM IP for a Moose pump and a fresh set of injectors. Last Septemeber I replaced the Moose with a Moose JR and fresh Conestoga injectors due to hot start issues. 2 months ago I sent the Moose JR in for warranty work after 6k miles and Mel rebuilt it due to a damaged head and rotor.

    After I recieved this current IP the Truck ran OK aside from some unusual oil consumption and an increased sensitivity to where I purchased my diesel and what fuel additives I was running. I use Stanadyne Lubrication Formula or Opti-Lube XPD.

    Historically this Truck has run very well and aside from some hot start issues that were resolved with IP's no other issues such as ticks, knocks or overheating.

    Last week while driving unloaded, it became difficult to maintain 70mph. The Truck was losing power and getting HOT. The temp gauge was nearly in the red and I could smell old oil cooking off of the engine. The EGT's were 1000-1200*F, the exhaust was billowing thick black smoke. The transmission was downshifting normally but the engine was being dragged down like I was riding the brakes hard. I quickly looked for a freeway exit and while keeping the throttle depressed as soon as I exited the engine died. I popped it in neutral and coasted to the side of the road.

    While waiting for my buddy to tow me home I attempted to crank the engine and it sounded slow and labored. Once I got home and the engine was cool I was able to start it and let it idle. As soon as I shifted it into D the load was too much and the engine died.

    The coolant level is normal, the oil is normal and there are no signs of oil or water mixing anywhere.

    I can't understand what would drag the engine down so severely and cause it to run so poorly. The fuel and air filters are fresh and clean. The timing is set to 8-9* BTDC.
     
  2. Thewespaul

    Thewespaul Supporting Vendor Supporting Member

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    I would send out the engine oil to blackstone and see what they find, for the fuel system issues would you happen to ever hear a hiss when you pull off the fuel caps? These fuel tanks dont vent well, and added pressure in the return lines will really screw with these pumps, but its not going to damage a head and rotor.
     
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  3. SLC97SR5

    SLC97SR5 Full Access Member

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    Thanks Wes.
    I am not concerned about the head and rotor, I only included that for backstory and I feel that the pump issue has been addressed.

    I've never heard a hiss from the tanks and it ran the same regardless of tank selection.

    I have more troubleshooting to share but I am curious if an IP could even cause the above symptoms?

    I swapped out the Conestoga injectors and popped them. They showed 15-1600 psi. I installed a newly rebuilt set of my OEM G codes. I popped each one prior to install and they all cracked at 1850ish.
     
  4. Thewespaul

    Thewespaul Supporting Vendor Supporting Member

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    That all sounds normal, I would pop the valve covers off and see if any rockers are loose, but with the truck billowing smoke I would lean towards something in the fuel system being your problem. With it being black smoke it would be unlikely to be oil from the turbo or engine burning off through the exhaust since that is normally a lighter blue smoke, and a moose junior barely makes smoke on a na engine so with the your truck having a turbo something had to be really wrong for it to smoke that much.
     
  5. SLC97SR5

    SLC97SR5 Full Access Member

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    When I swapped injectors I was greeted by something I've never seen on this Truck. 1 injector on each bank looked like this.
    20190903_143219.jpg 20190903_123658.jpg
    Head gaskets? Both sides at the same time?
     
  6. SLC97SR5

    SLC97SR5 Full Access Member

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    The Truck now has a verified fresh set of injectors and a CDD pump with 300 miles on it.

    Do I swap in my junk yard IP for "fun"?
     
  7. SLC97SR5

    SLC97SR5 Full Access Member

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    I performed a compression test on 6 of the 8 cylinders.

    Here are my numbers on a ambient temp (80*f) engine that had sat for several days.

    After dripping 10 drops of oil through the GP hole it only came up 20psi. 20190905_105428.jpg
     
  8. Thewespaul

    Thewespaul Supporting Vendor Supporting Member

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    Left side looks like typical soot buildup from the copper washer leaking combustion past the injector, the second injector looks like theres no combustion happening in that cylinder and youre getting some coolant in there making the muddy look. I would leave the pump on for now, and pop the valve covers off and drain the oil first.

    Edit, those compression numbers are on the low side, definitely pull the covers off and check things out first.
     
  9. SLC97SR5

    SLC97SR5 Full Access Member

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    Screenshot_20190911-090853_Gallery.jpg I have the passenger side valve cover off and everything looks great, after seeing those 2 injectors covered in goop I was not expecting the rockers to look very good.

    Everything is tight and appears to move properly when cranking the engine over.

    I set the damper @ eleven o'clock to unload the valve train and I can spin all of the pushrods with moderate finger pressure. Nothing appears bound or has a bunch of run out when rotated.
    All of the rockers were tight.
     
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  10. Thewespaul

    Thewespaul Supporting Vendor Supporting Member

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    All that looks good, surprisingly clean too. Did the muddy injector come from that bank?
     
  11. SLC97SR5

    SLC97SR5 Full Access Member

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    No. I misspoke. I have the driver's side VC off. The muddy injector is from the PS hole 6. The sooty one 20190911_100340.jpg is from DS hole 7.
     
  12. Thewespaul

    Thewespaul Supporting Vendor Supporting Member

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    I figured that, looked like driver side. A lot easier on that side than the passenger side.
     
  13. SLC97SR5

    SLC97SR5 Full Access Member

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    Any shortcuts for removing the PS cover?

    Also, I've had a knock develop over the last 10k miles that comes and goes. I've never been able to isolate it. It is most apparent when coming off of idle, lightly loaded. Like when pulling into a parking lot or creeping up a few car lengths in traffic.

    Are the compression #'s of concern with only 190k? I was worried about them.

    I've always used a FL1995 filter or a Wix Gold with Delo. I change it @ 2500-4000 miles. Maybe it is in my head but it seems like the knock developed shortly after Delo changed formulas.
     
    Last edited: Sep 11, 2019
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  14. Thewespaul

    Thewespaul Supporting Vendor Supporting Member

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    Put a block of wood under the passenger side front body mount and lift it up a bit with a jack just to take some of the weight off the frame, it will give you a lot more space between the engine and ac box. I leave the fuel filter bracket in place just use 1/4" u joints to get to the hard to reach bolts/nuts and pull the fuel filter.
     
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  15. IDIBRONCO

    IDIBRONCO IDIBRONCO

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    That's what I do. Just without jacking up the cab. It's tight, but it comes out.
     

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