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Macktech689

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Posts posted by Macktech689

  1. Your problem sounds nearly identical to a common rail I had a couple of weeks ago, cold start misfire. Installing a different solenoid valve to lower the rocker pressure fixed that one. Higher than normal pressure was unseating the brake pistons far enough to slightly open the exhaust valves and lower compression causing the misfire. Just food for thought, take it for what it's worth.

  2. On ‎2‎/‎15‎/‎2019 at 10:29 AM, fjh said:

    So I'm fishing for info here we have  the afore mentioned truck  sits over night ,it starts clean then ten seconds or so into the run it starts missing and stumbling like its passing an air bubble past the injectors then cleans up  and runs Ok  No CODES ! Now the guy is quite fussy and is not happy with this anomaly that has started here  with in the last couple of days Is been cold here 5 or so below freezing not sure if this has anything to do with it however! not sure where the check valves would be on the system or if its loose its prime on the high side or the low side  of the system ,  the fix we thought might repair this the rail sensor and harness  did not correct this condition ! Having Zero experience with this  fuel system  its going to be  hard to nail this down ! Searching for clues to this issue if  anyone has ANY experiences feel free to pipe up!   Should we be Taking an oil sample to see if there maybe fuel in the oil ? using the pretense that where there is  Air there is likely a fuel leak???  No visible leaks on the outside!!!

      Reasonable Opinions?

    Setting fire to it Is not an option At this point! 😁

    What you are probably dealing with is high oil pressure in the rocker shaft causing  low compression when the oil is cold, usually cause by running 15W40 instead of 10W30. Next time you check it cold install the gauge set on the front of the head. rocker pressure should be below 120 kPa, if the pressure goes to 150 kPa report results to tech support.

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  3. 14 hours ago, fjh said:

    Yes But Out THE box? Sorry  But I don't believe ,I /we should have to take a" new" out of the box valve apart to make the son of a bitch work!

    Just sayin!

    I totally agree but the reality is they sometimes get stuck during storage. I got burned by 1 in 2008 and have been checking them first since then. About half have been OK and the rest were stuck, only takes a minute to check the spool in the valve. 

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  4. The most likely cause of a MP-8 pushing coolant is the EGR cooler or injector sleeves. The first step is to perform a combustion leak test on the surge tank, if the test fluid turns green combustion gas is present in the cooling system. Check the cooler first by removing the hose and elbow and looking for coolant or chunks of soot in the cooler outlet. If your cooler looks OK you should get the sleeves replaced. I have never seen a head gasket failure on these engines. If the test fluid stays blue check your air drier for coolant. 

  5. The TRLR AUX switch operates the center pin hot system. It is used to supply 12V to the trailer center pin only when the key is off. It is used by gasoline tanker trucks to operate the over fill protection devices on the trailer when loading. The switch will not power the center pin with the key on or parking brake released. When the key is on the center pin is powered all the time to operate trailer ABS systems.

  6. Replacing the actuator requires use of premium tech tool software. PTT has always had a operation to install and calibrate the actuator, if you put it on without doing it right the malfunction light will stay on and the turbo won't perform properly. You're dealer will have to do it, takes less than half an hour. 

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  7. The easiest way to check to see if the fan is capable of engaging is to disconnect it from the engine harness and run the engine over 1000 rpm. The fan should fully engage in around 10 seconds, if it doesn't replace the fan drive. Loss of voltage triggers a limp home mode, keep in mind the fan drive will rarely fully engage during normal operation 75 to 80% is normal.

  8. There was no change to the flywheel housing when the staked idler gears were installed, removing the housing is no small job the back and bottom of the engine needs to come off. You can check the idler gear through the PTO cover at the top of the housing on the right side to see if it is loose, if it is you will also see where it's rubbing on the housing. The video you mentioned may have been of a MP-7. A good picture of the top of the housing would be helpful, a pic of the bottom won't show anything.

  9. The harness for that engine runs in the $600 range I think, I don't buy them I replace them. I've replaced dozens of engine harnesses, it's not a bad job as far as I'm concerned. The worst part of the job on a 04 emission's MP-7 is getting the harness disconnected from the mass flow tube module behind the alternator bracket.

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