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+--- Thread: cm2250 derate (/showthread.php?tid=8363)
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RE: cm2250 derate - Rawze - 08-09-2022
yes.. the first priority is to get it to pass a rail leak test, as specified in this video...
ref: http://rawze.com/forums/showthread.php?tid=7915&pid=69262#pid69262
after you can get to pass a rail leak test with less than 4,000 psi leak rate in one minute.. then you can start with the other issues.
An EGR tune-up would be the next step.. replace the IMAP and exhaust gas pressure sensors, clean out the EGR piping, giving it a general tune-up, etc.
RE: cm2250 derate - solo_shooter_ - 08-10-2022
Okay, I replaced the tappets and plungers, re-tightened all fuel connector nuts and performed the leak down test. I started the test out at 28,906 psi, at the 30 second mark I was down to 9,050 psi and at 60 seconds I was down to 4,983 psi. So I am aware that there is a severe leak somewhere inside this fuel system but not sure where to go next. Possibly a bad injector? Or a cracked head?
RE: cm2250 derate - Rawze - 08-10-2022
(08-10-2022 )solo_shooter_ Wrote: Okay, I replaced the tappets and plungers, re-tightened all fuel connector nuts and performed the leak down test. I started the test out at 28,906 psi, at the 30 second mark I was down to 9,050 psi and at 60 seconds I was down to 4,983 psi. So I am aware that there is a severe leak somewhere inside this fuel system but not sure where to go next. Possibly a bad injector? Or a cracked head?
the first priority is to get it to pass a rail leak test, as specified in this video...
ref: http://rawze.com/forums/showthread.php?tid=7915&pid=69262#pid69262
after you can get to pass a rail leak test with less than 4,000 psi leak rate in one minute.. then you can start with the other issues.
======================
if it still fails ... next would be to replace the high pressure relief valve on the front end of the rail and then do the tests again.
After that, if it still fails a leak down test, you will need an injector block-off kit so that you can cap off up to 3 injectors at a time to find the bad injector(s).
RE: cm2250 derate - solo_shooter_ - 08-10-2022
I swapped the rail pressure relief valve with one off of our other 2250 before I did the test. Same issue. I will have to order the block off kit.
RE: cm2250 derate - Rawze - 08-10-2022
(08-10-2022 )solo_shooter_ Wrote: I swapped the rail pressure relief valve with one off of our other 2250 before I did the test. Same issue. I will have to order the block off kit.
how do you know that other 2250 passes a rail test?/.. did you test that one too?.
RE: cm2250 derate - solo_shooter_ - 08-10-2022
I did not, I assume it is fine considering that engine isnt having rail pressure issues. I ordered a new relief valve so I will try in the morning.
RE: cm2250 derate - Rawze - 08-11-2022
(08-10-2022 )solo_shooter_ Wrote: I did not, I assume it is fine considering that engine isnt having rail pressure issues...
Those fuel rails get leaky long before they ever start throwing any codes for it. .. never make assumptions like that.
The pressure relief valve is cheap compared to what has to happen next towards solving rail leak issues. Swapping it from another truck is ok.. but the other truck needs to pass a rail leak test first too.
Repalce the pressure relief valve and do the tests again.
If it still fails.. remove all the fuel lines going to the cylinders and re-torque all of the injector feed tubes.. then re-assemble everything... do the test again.
If it still fails then you need a block-off kit and start blocking off injectors and doing the tests again until it is found.