M4900 injectors

North Idaho Wolfman

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Nothing fancy needed, just unscrew parts with good wrenches and sockets.

DO NOT bend the injector lines out of the way to remove the injectors, loosen or remove both ends of the line to get the injectors out. ;)
 

Magicman

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My question isn't about removing the injectors, but sorta related.

All 5 of my injectors and the area surrounding them are wet. Not dripping wet but wet. I have not had time to do any diagnostics nor tried to tighten anything. Normal? What to look for?
 

North Idaho Wolfman

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My question isn't about removing the injectors, but sorta related.

All 5 of my injectors and the area surrounding them are wet. Not dripping wet but wet. I have not had time to do any diagnostics nor tried to tighten anything. Normal? What to look for?
Not normal, and you have a leak somewhere.
Start by using brake parts cleaner to clean all the ridual diesel off then start and run it and look for leaks, if nothing obvious dust area with baby powder, then blow off dust what's left is the leak.
 

Magicman

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That's what I figured. I am prepping for total knee replacement surgery and have not had/taken the time to investigate.
 

D2Cat

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Magicman, get out there before the surgery and get it cleaned so you can see the leak. Then you can meditate on the fix all the time you're healing. By the time you're ready to actually get it fixed, you'll have gone over it many a times and it will be "duck soup" to fix! You'll know every part needed, every wrench, and every sequence to get it done. Good luck with the new knee!
 

Magicman

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Thanks, I'll try to do just that. My surgery is scheduled for the 18th, but there is sooo much that I need to do between now and then. :eek:

I tried today: LINK
 
Last edited:

Magicman

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I took a look today. Wow, that is a tight squeeze to even see them. Does the fuel tank have to come off. Looks like it does, either that or the intake manifold. :eek:
 

Snake

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Okay, back to my m4900 injectors. First, thanks for the response. Got injectors out. Little rust on the tips. Cleaned them as best I could. Tractor hard to start but eventually ran. Rough. My question is this. All 5 on the injection pump look the same with the lines off. Fuel is good. When tight, runs rough. Cracking lines. 1, 3 , 5, no difference. 2 and 4, engine slows down. Re tighten, engine speeds up. Is there an adjustment On the pump at the fitting below the nut. It seems a bar against knurls stops them from rotating. Thanks in advance.
 

Russell King

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Move injector from 2 to 1,3 or 5.

Does the bad cylinder follow the injector? Does the cylinder with injector from 2 run properly now?

Then the injector from 1,3,5 should be replaced.


Sent from my iPad using Tapatalk
 

North Idaho Wolfman

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Snake,
DO NOT adjust or even mess with the injection pump, there is no adjustments that you can make.

Your problem is the injectors are shot, have them pop tested.
While your at it do a compression test.
 

thepumpguysc

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2 & 4 are the only ones working..
Ur gonna hafta spend some money to get this fixed..
Smart money has the injectors checked & o/h'd if needed, first.. {least expensive}
THEN the injection pump.. if the prob. isn't solved by the fresh injectors.
IF u loosened the top nuts on the inj. pump.. u screwed-up the equal delivery to each cylinder.. {Just something to think about..}
 

Snake

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Wildman, unfortunately the bottoms moved when I loosened the flarenuts at the pump to move the lines. I just tightened them back up and snugged the torx screws holding the little bar against the knurls.
 

North Idaho Wolfman

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Sandpoint, ID
Wildman, unfortunately the bottoms moved when I loosened the flarenuts at the pump to move the lines. I just tightened them back up and snugged the torx screws holding the little bar against the knurls.
If they moved back to there prior location / setting then they are fine, if they did not then you'll have to have the injection pump rebuilt.

I would get the injectors tested / replaced before you do anything else as they are most likely the root cause of your issues.