Oil & Fuel JD450B starts but won't stay running

   / JD450B starts but won't stay running #1  

Daveintexas

New member
Joined
May 29, 2011
Messages
9
Tractor
John Deere 450B
Was out pushing down cedar trees and engine just kind of gradually lost rpm until finally dying. Started back up and would run for maybe 30 seconds before doing the same thing. Thought it could be the diesel transfer pump so replaced it along with checking/cleaning fuel filters with no luck. Each time it will start but only run for a few seconds whether hot or cold. Seems like I have good fuel flow to the injector pump but not sure where to go from here. I added fuel recently but have to admit that the fuel that had been in it when it first started having problems has been in there a while. Thought I would just go ahead and drain it and start over but not sure this is a problem since it was running good for quite a while before it started acting up on the day this first started happening. Any ideas on what to check or test would be helpful. I don't have the equipment to haul this beast to a repair facility.
Thanks,
Dave
 
   / JD450B starts but won't stay running #2  
Any chance a limb or some such got up into the linkages or the like.:)
 
   / JD450B starts but won't stay running
  • Thread Starter
#3  
While there are pieces of limbs which get everywhere the linkage to the injector pump is fine and works like a champ for the short time it runs.
As a bit more info, I bought this 70's vintage machine several years ago and the engine had been rebuilt prior to my buying it. Aside from replacing the starter motor and fixing a leak in the radiator this machine has run great.
 
   / JD450B starts but won't stay running #4  
Sure sounds like you've got a fuel issue... Have you tried cracking the injector lines at the pump (one at a time) to see if you've got fuel pressure to each one? All your lines are good - no weather checks or leaks?

Is it possible that you've only got partial flow from the tank to the transfer pump? Got any green/brown goo growing in your tank?

And it appears everything is OK from the transfer pump to the injector pump?

AKfish
 
   / JD450B starts but won't stay running
  • Thread Starter
#5  
Draining the tank right now however the fuel draining out looks good and clean (suprisingly). There was some of that good old green/brown goo in the bottom of the filters but that has been cleaned and the filters were doing their job such that the output looked good. I have checked all lines and no leaks anywhere. Tried cracking just one of the injector lines to be sure there was pressure but have not tried them all. 3 will be easy but that 4th might be more of a challenge. Have to go to town in the morning to get more fuel so with fresh in the tank will then flush it thru to the injector pump. Going to replace the filters as soon as JD opens again on Tuesday. Would normally do that first but the holiday messed that up and I am getting what seems to be good clean flow right up to the injector pump. If fresh fuel doesn't do the trick and filters don't help then I'm guessing the next step might have to be injectors if they all seem to have pressure at the pump. Sure hope that's not the case but will find out I guess.
Dave
 
   / JD450B starts but won't stay running #6  
Dave,
While you are working on all of this I recommend you look at the rubber return line hoses linking all the injectors together. These can get old and will crack and can leak fuel on the exhaust manifold starting a fire. Just something to check while you wait.

Might want to add some biocide to the fuel tank too when you refill.
 
   / JD450B starts but won't stay running
  • Thread Starter
#7  
Thanks to everyone so far. All these ideas have been helpful. One thing I noticed in trying various things is that after I have opened/closed a fuel line at the injector pump which relieves the pressure then the next time I start it up it will typically run slightly longer so I'm suspecting that the return lines could be clogged versus leaking. I already checked for leaks but found some other posts talking about clogs in the return causing this type of problem. Of course I have now drained all fuel and need to go get more before trying any more ideas but thinking the next step is to check that the return line is clear as well as opening up the timing window as was suggested elsewhere to see if relieving pressure helps. This has been an interesting experience so far. Learning more than I wanted to know about this system. Of course, as we all know, breakdowns always occur when you need the machine the most. In my case I need to lift some 2+ thousand pound items into place and everything is waiting on getting this working. Assuming I may need an injector pump (Roosa Master JDB435) does anyone know where to get a rebuilt one?
Dave
 
   / JD450B starts but won't stay running #8  
Try removing the timing window on the injection pump. It is a rectangular cover about 3/4" X 1 1/2" held on with two small screws. When you remove the window(cover), see if there are any black coffee ground appearing stuff in there. If so then the pump is in need of repair. While the window is off try starting the tractor and see if it will continue to run. (put a bucket under the pump area first, fuel will leak out) When the cam ring in the pump fails and produces the coffee grounds material, it clogs the return fitting or line and causes too much case pressure in the pump, causing it to shut off. Allowing the fuel to leak out of the timing window will allow it to continue to run. jdemaris has excellent threads on how to repair the pump yourself if you desire.
 
   / JD450B starts but won't stay running
  • Thread Starter
#9  
BINGO - Just came in from checking return lines and removing the timing cover and saw your post. There were many 'coffee grounds' or 'mouse turds' as I've heard them called. Now can you tell me how to get to the threads you mentioned? Not sure if I'll do it myself or find a rebuilt unit but would like to read thru the repair or perhaps just replacement do's and don'ts. I'm sure something must be marked properly to be sure it goes back in correctly.
Thanks for verifying that the pump is my (or at least one) problem. Would have preferred something less costly but you get what you get. I'm glad to be on the path to having this fixed. Just spent a few minutes trying to call my local mechanic before realizing (duh) this is Memorial Day. I retired at the end of last year and now the days just seem to run together and I lose track.
Thanks again.
Dave
 
   / JD450B starts but won't stay running #10  
Dave,
If you can take the injector pump off and carry it in to a good injector pump shop you should be able to have it rebuilt while you wait (with an appointment). Expect between $400 and $800 to rebuild it. Don't know where you live in TX but there is a good shop in Amarillo.

I should add that they can tell you how to index before you remove the pump.
 
 
Top