'68 450 diesel fuel system mystery

[NaEh-in-New-York]

hello hello, so a few months ago I was moving along in the forest on fairly soft ground and went over a medium? rock. The front end went up and I came down hard and the engine completely died almost instantly when I hit the ground. After poking and prodding I've got it down to a fuel system problem due to the lack of any fumes out the exhaust when I turn it over.
I've changed the filters, bled the air out and the lift pump is certainly still working so it is probably the injector pump? I've got 8Volts at the pump which the manual says is sufficient and it stays at 8volts no matter how I wiggle the wire around, checking through the stud on the side of the pump or directly to the frame I still consistently get 8 volts so the connection is stable at least.
The pump is buried behind the loader arm and I can't even get a good look at it unless I dive in headfirst from above let alone reach it with tools, so I've been reluctant to start wrenching on it without some kinda idea as to whats wrong on the inside.
It's a Rosamaster pump by the way. As far as I can tell it's just the plain one not a model C.

Thanks, Will

[B Town]

Hello Sir,

Check the voltage from the negative post to the positive post of the battery? Is it 8 volt, also? If so, it is possible the jolt may have knocked out one of the battery cells or the cell was dead before up and down jar.

It is possible the jolt knock the cell out and now the starting system is unable to crank the engine fast/forceful enough to start it. If the cell was dead before the incident and is unrelated, it probably should still be addressed.

When you turn the key on and off, can you hear or feel the fuel shut-off solenoid opening and closing?

Do you have one battery or two batteries in parallel? Are the batteries secured or floating loose?

Is the injector pump putting out fuel while the engine turns over? If your injection pump has a pellathane governor ring, I suppose it is possible the impact could have disturbed it immediately.

Best regards,
Bruce

[LeonardL]

Well... I would start by throwing what ever tech manual you have as far as you can throw it and then go pick it up and throw it that far again. If it actually says 8 volts is plenty of voltage to run... It's wrong. Even if it is a John Deere manual. I have never seen a Roosa Master pump solenoid work properly with less than 12 volts. If you don't have 12 volts at that stud and or through it then you're not getting proper voltage to the solenoid. You may have other issues as well but I would start by getting 12 volts to the pump first of all and then try again. Check your battery first to make sure it is carrying at least 12 volts and if it is okay then you can run a jumper to the stud on the pump directly from the battery.

[LeonardL]

Sorry Bruce we must have sent at the same time!! I would have stayed out of it!!

[B Town]

Sorry Bruce we must have sent at the same time!! I would have stayed out of it!!

No problem here. We are of the same mind.

Take care

[NaEh-in-New-York]

Thank you!
Two batteries in parallel, it was turning over just fine right before hand and when I checked the voltage(after turning it over several times) it was pretty close to 12V(11.8 or something). There isn't that bad of self discharge and when I checked them separately they both had the same voltage and comparable voltage drop when I put a load on them so I don't think there is a bad cell. I've also taken them out of the circuit and tried a different tractor's battery and still nothing. I was REALLY wondering about the 8Volts the manual said, it just didn't seem right .
There is a little bit of fuel coming out of the return for the pump but nothing from the other ports, and no I have not been able to tell if the solenoid is engaging or not. I wasn't sure if it was really quiet or not working but after putting my hand on it and turning the key to ON I couldn't feel anything so my guess is no.

Is there any kind of timing control done through the wire or is it just power? When I looked at the wiring diagram there were several "black boxes" involved so that was unclear.

Definitely an official manual and as far as I can tell it's not made up of several different ones pieced together. cross my fingers here

Will

[Jim B]

I'll leave most of this to Bruce and Leonard to avoid confusion, but do have a couple things to throw out. First, the wire is just a power wire; no computer controls on a 450 I know of. You can use a jumper wire from the battery positive to put full battery voltage to the terminal the wire currently hooks to on the injection pump. Look carefully at the top of the pump. Directly across from the terminal with the wire there should be another insulated terminal. That terminal should have a small metal dog bone strap between it and one of the cover screws. That is the ground for the solenoid. I have know of those breaking or losing contact; no ground the solenoid won't work.

I can't see the schematic you are looking at, but on one I found it has some plug together connectors that join the harness sections that I guess might give the impression of being black boxes; however they are just connectors usually found where the wires go through bulkheads/panels. How are you load testing the batteries and what is the voltage at the battery wire on the starter solenoid when cranking?

If you have an official John Deere Service Manual it should have a publication number on it. For a 450 that number is SM2064. Is that the one you have?

Jim