Maxforce 13 Low Power, will not pull at higher speeds.

Discussion in 'International Forum' started by Yippykyae, Feb 13, 2024.

  1. Yippykyae

    Yippykyae Light Load Member

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    There was a thread about injector wires being cut under the valve cover.
    I had a tech read my codes but his software could not read any data on the #6 injector. It was just not there.
    If I had an injector not working what would my symptoms be? Would the truck still go 75mph.
    Would I easily be able to tell the injector was not working or would it be wide open pumping fuel?
    I have low power and poor mpg. Power on the low end is OK but it will not pull at higher speeds?
    Any input is appreciated.
     
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  3. JB7

    JB7 Medium Load Member

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    What were the codes? Difference between codes and data. Codes give a number with a description of a problem. Then a procedure for finding what caused the code. Examples of data would be temperatures that the ECM is reading or injector open time in milliseconds. Tech should have run a balance/cylinder cut out test. If there were cut injector wires or other issues there would/should be a code for that cylinder/injector.

    Has anyone checked the air filter? The connections before and after the charge air cooler should be checked. Best to smoke/pressure test which will also check the cooler. Check the oil level and to see if it smells like fuel.
     
    Yippykyae Thanks this.
  4. Yippykyae

    Yippykyae Light Load Member

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    He said there were no codes. he was doing the cut out test and they were all good but it would not show any data on #6. It was not there at all.
    The oil is good. Would the truck still go 75-80 mph if an injector was not working? I was thinking about pulling the top and looking at the wires. My knowledge is limited and I don't have the money to just throw at it. It has a new air filter. I will look at the wires at the charge air cooler. I saw a thread saying they have found wires cut under the cover. Thanks for the help.
     
  5. JB7

    JB7 Medium Load Member

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    "he was doing the cut out test and they were all good" Including # 6 ? When one cylinder,is cut off/out if everything is good, the engine will miss and run rough. If it did this on # 6 then that one is ok. Not sure if you mean there was no change when 6 was cut out or if there was a noticeable change but no data which is puzzling. Engine has 6 cylinders, if one not working for whatever reason, that is about 17% (100/6) of the total and would be noticeable. Unlikely truck would go 75-80 with a dead cylinder. "I will look at the wires at the charge air cooler." Not the wires but the hose clamps and connections, all of them before and after the cooler. Can't hurt to pull the cover and check all the wires and rocker adj. But I doubt there is a problem with only #6. More tests need to be run.
     
    Yippykyae Thanks this.
  6. Yippykyae

    Yippykyae Light Load Member

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    He could not test #6 because his computer did not show that #6 existed. The truck starts up immediately. it has a little rough hesitation when pushing the throttle, it idles fine though. It will get to 40-50mph fine but struggles after that by taking a long time to make speed and it cannot maintain speed going up even a small incline/hill.
    I agree, more testing but I like to look for the basic stuff first and I know that sometimes the guys with experience can zero in on things.
    Thanks, again.
     
  7. mikesouthbend2

    mikesouthbend2 Bobtail Member

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    I have 13 prostar with maxxforce 13 and have had the same problem for years. I replaced all 6 injectors and it helped a lot on take off but the top speeds even empty with a small hill are horrible. If I see a hill I speed with everything I have and hold my breath and been doing this for years. I am in Indiana and won’t go too far into hilly areas. One thing that does work for me is if I am coming up on a hill flip the key off and back on really fast and it resets ECM and will go full speed up a hill. I only do this if I am up to full speed and I let off the accelerator for a second and do it fast and it goes full power every time. God only knows what is up with these trucks. I bought mine 6 years ago with 450k miles and now has 820k miles and only new injectors and basic replacement things so far knock on wood. Good luck out there!
     
  8. Yippykyae

    Yippykyae Light Load Member

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    That is very interesting, I wonder what is going on? I don't want to replace the injectors without knowing that it needs them. I was thinking about the high pressure turbo. Maybe removing the cartridge and cleaning it. JB7 has got me thinking about the charge air cooler but you have me wondering about the tuning. I drove another one of these trucks and it did the same thing but maybe worse than mine. They should not have this problem and there has to be a reason.
    There must have been something wrong with the software the tech used to look at my truck.
     
  9. Yippykyae

    Yippykyae Light Load Member

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    Do you get / have a check engine light? Maybe something is telling the system to limit the turbo boost pressure?
     
  10. Yippykyae

    Yippykyae Light Load Member

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    Or limiting the fuel to the injectors.
     
  11. Yippykyae

    Yippykyae Light Load Member

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    It this engine doesn't have an IPR or ICP sensor how does it regulate pressure to the injectors?
     
    Last edited: Feb 17, 2024
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