Heavy Equipment Forums Heavy Equipment Community

JLG telehandler no start issue

Cat.man · 2023-12-09 23:50

Got a JLG with a cummins QSB4.5 engine, so the engine radiator was pressure washed, machine started and moved a short distance and shut off, started back after trying for some time would idle then shut off under load, now it doesn't start at all. Active codes for all injector drivers and intake mass air flow. Please advice on how to go about troubleshooting issue. Cranks at around 160rpm and builds around 5000psi fuel pressure.

Replies12
  1. #1Mechanicsville8042023-12-11 09:34

    Have you tried to disconnect the connections for the injectors just to see if you have water in them? also with the Mass Air Flow sensor?

  2. #2Cat.man2023-12-11 14:18

    Hey no I have not disconnected any harnesses or anything yet

  3. #3Mechanicsville8042023-12-11 18:58

    I would try and see if there is any water in any of your connectors first. I’m also curious if your machine wouldn’t start due to the power wash and now it’s been a few days if with the codes you got if you couldn’t just crack the lines at the injectors while you crank the machine to prime the fuel system if it wouldn’t start up and run again

  4. #4Cat.man2023-12-11 19:51

    I'm gonna disconnect all connectors from ecm out and crank lines and crank and see what happens

  5. #5Cat.man2023-12-11 20:47

    Do you have wiring schematic for engine harness?

  6. #6Mechanicsville8042023-12-12 07:40

    No I am sorry I do not have access to schematics

  7. #7Cat.man2023-12-13 15:16

    Hey so I removed all connectors from ecm to all sensors on engine, there was a bit of moisture. Contact cleaner all of them and reinstalled but did not fix the issues.

  8. #8Mechanicsville8042023-12-13 15:25

    Since you have a picture of all of your codes I would try to clear the codes and then attempt to start the vehicle, If it cranks and no starts on me I would then look to prime the fuel by cracking the nuts at the back of the fuel injectors one at a time while someone cranks the engine to see if I am getting fuel to the engine and to get the air out if somehow air got trapped in the fuel.

  9. #9Cat.man2023-12-13 15:54

    Did try clearing codes but they are not clearing

  10. #10Mechanicsville8042023-12-14 07:17

    Ok, I'm sorry this is about all I can figure to do with out being there to help you.

  11. #11Cat.man2023-12-14 07:51

    Do you think it could be a ecm issue?

  12. #12Mechanicsville8042023-12-14 08:31

    It could be, and it could be anything, it’s hard for me to say right now. If I was working on the machine I would be 100% sure the ECM is bad before I purchase a new one, I would not just guess and put one on.