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1959 411.110
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Discussion Starter #1
I'm trying to start an OM636 in a 1959 411 that hasn't run in years; I am much more comfortable with gasoline engines so excuse the possibly stupid questions;

Is it possible the injection pump is not being driven? I have valve train movement and oil pressure when cranking but no visible movement of the plungers when I remove access plate to the injection pump body. I can get fuel to the filters and pump via the hand primer pump but no delivery when cranking.

Is there an easy way (without disassembling timing cover) to determine if the pump is being driven when cranking? Timing mark? Hour meter?

How do neglected pumps typically fail? Seize? Leak, etc.

Thanks in advance for any help.

Thomas Santoli
 

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LAND ROVER 90 / DISCOVERY BOTH FITTED WITH TWEEKED PERKINS PRIMA ENGINES UNIMOG 404
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121 Posts
om636

it will be the delivery valves thats stuck ,if you remove the injecter pipes then loosen the eliments in the pump this should alow the delivery valves to free also remove the fromt plate from the pump flush with penitrating oil .you will see the rod that moves the rack, this may need freeing .plenty of oil and gentle move ment should get it working .under the rear cover you will find the vacume belows check for spliting .hope this helps.
 

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Registered
1959 411.110
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84 Posts
Discussion Starter #3
Thanks, a few follow up questions;

The elements seem to have a lock/ wedge screwed in place; no problem removing this and unscrewing the 4 housings that the injector feed pipes connect to?

The front plate is the plate on the side by the primer held in place with two screws?

When operating normally, should I see the plungers/ springs cycle under the plate referenced above? Do these cycle regardless of throttle/ governor position?

Thanks again,

Tom
 

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LAND ROVER 90 / DISCOVERY BOTH FITTED WITH TWEEKED PERKINS PRIMA ENGINES UNIMOG 404
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121 Posts
pump

the eliments rise and fall with the cam ,then the amount of fuel is controled by the rack rotating the eliments to control the amount of fuel deliverd to the injector .if you move the stop lever at the vear of the pump inbetween block and pump push forward goes to over fuel to asist starting pull back for stop this will help you see if rack is free .hope this helps
 

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My om636 hadn't run for 3 years. After bleeding the Air in the system, it fired right up.

Pump till you have fuel in the fuel filters, So crack open the fuel filter bolts and make sure there is fuel. Tighten

Next:
crack open each injection line coming out of the mechanical injection pump and crank over the engine or hand pump till fuel begins to leak out, once it begins to leak out of all 4 lines retighten.

Next:
Crack open the injector lines and crank over the engine or hand pump till fuel comes out, once fuel is seen on all 4 lines you know the system is bleed of air, and should fire right up.
I find myself giving the engine 1/2 to full throttle helps to get it to fire faster. Not sure if that's that way, but it works for me.

I hope that helps you
 
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