How to change oil in sims fuel injection pump

The Caterpillar 3412 engine is a large industrial engine commonly used in various applications such as marine, power generation, and heavy equipment. The fuel injection pump is a critical component of the engine's fuel system that is responsible for delivering fuel to the engine's combustion chambers at the correct timing and pressure.
To provide more specific information or assistance regarding the Caterpillar 3412 fuel injection pump, please provide additional details about the specific issue or question you have. This can help in addressing your query accurately and offering appropriate guidance.

it should not be necessary as the pump is lubricated with engine oil that drains back to the sump or in rotary pumps , is lubricated with diesel fuel

See id it is actually pumping fuel and if so see if the glow plugs are getting hot.

Maybe it causes by the following problems:

Fuel System Failure

1. Air in the fuel system
This is a common problem that a diesel generator fails to start normally.
Solution: Check whether the fuel oil pipe connector is loose or not, and ensure that the air is cleared from the fuel system. Loosen the bleed screw bolt on the diesel filter, and then use the manual oil pump to pump the fuel until the air bubble is gone.
2. Fuel Line Obstruction
Solution: Check whether the pipeline is smooth or not.
3. Fuel Filter Clogging
Solution: Clean the filter or replace the filter element
4. The Handle Position of Fuel Injection Pump Is Not Correct
Solution: The handle position should be pushed to no-load when starting the diesel generator set. Rotation speed is about 700-900r/min.
5. Fuel Injector Problem - Little fuel injection or fuel injection is not atomized
Solution: Remove the fuel injector, connect it to the high pressure oil pump, pry the fuel injection pump plunger spring and observe the spray condition. If necessary, wash the injection pump.
6. Oil Supply Problem - Oil transfer pump doesn't supply oil or the oil supply is brokenly.
Solution: Check whether the oil inlet pipe is leaked or not and the filter screen on the oil inlet pipe connector is blocked or not.
More information at article.
https://www.dieselgeneratortech.com/diesel-generators/why-diesel-generator-fail-to-start.html

That's s failure of the secondary air pump. It'll have to be changed. It's an emissions component meant to help with cold start emissions. It won't cause engine running trouble but at inspection time you'll fail for smog. Change it before then and you'll be fine.

1st check the Fuel Pressure. Often times a fuel injection system fuel Pump ran dry, can more or less implode, the suction becomes too strong and ruins the diaphragm, thus causing low-to-no pressure. faulty fuel pumps can run just slightly under the fuel injection systems Low tolerance, causing the issues that you have mentioned. this is not 100% the answer just a good place to start. Low fuel pressure= change fuel filter, still low pressure= fuel pump. The cheap carport mechanic method would be to change filters first, if the have been changed recently, move toward replacing the Fuel Pump. (some pump are located in the fuel tank, if yours is not your in luck!)

The fuel pump relay and the oil pressure switch as well. The oil pressure switch runs power to the fuel pump when you first start it
When the oil pressure reaches operating range the relay takes over
They are both inexpensive so replace both of these parts to be safe and kill two birds with one stone. If one goes out the other will soon enough

Have you changed your oil? Rotella 15W-40. These engines really don't like old oil. It becomes too thick for the injection pump to work correctly. Another possibility is a bad cam sensor on the front of the motor. Most engines call this the crank sensor but on this engine you have to look it up as a cam sensor.

SOUND LIKE THE ELECTRIC LOW PRESSURE FUEL PUMP CHECK FUSE TO SEE IF PUMP GETTING POWER. IF NOT REPLACE FUSE AND CHECK THE WIRE TO PUMP.IF PUMP IS GETTING POWER..REPLACE FUEL FILTER FIRST.IF IT DONT HELP.COULD BE THE ELECTRIC LOW PRESSURE PUMP. FAULTY. IT PUMPS DIESEL FUEL IT INTO INJECTION PUMP TO BE PRESSURIZED TIMED AND INJECT.SEE IF LOW PRESSURE PUMP DONT WORK THE WHOLE ENGINE WONT RUN.THE INJECTION PUMP NEED FUEL FROM LOW PRESSURE ELECTRIC PUMP TO RUN ENGINE.

Could be one of many things:

-Clogged fuel filter
-Leaking fuel line
-Bad fuel pump
-High or low oil level
-Overdue oil change (Will explain both these possible causes later)
-Bad high pressure oil pump, ICP sensor (injection control pressure sensor), ICR (injection control pressure regulator), or bad HEUI injectors, or oil lines
-Leak in the high pressure oil system (unlikely because you would have noticed this... This does not go undetected as the underside of your vehicle would be literally covered in oil and dripping in a very short period of time after the leak develops)
(Powerstroke engines use a HEUI fuel injection system, "Hydraulically actuated/electronically controlled unit injection", which relies on a high pressure hydraulic pump that uses engine crankcase oil and pumps it at high pressure (500 psi or so). This oil is sent to your fuel injectors to provide means for actuating them and pressurizing the fuel into the cylinders. High or low engine oil level, or old, diluted, additive depleted oil will cause this system to aerate the oil and result in poor fuel injection capabilities)

There might be other causes but this is the Powerstroke`s weak point... The HEUI system was first designed by Caterpillar, which makes a lot of excellent/bulletproof HEUI based engines, both in passenger vehicle and heavy trucks and equipment. The Powerstroke is an engine designed and made by International Truck and Engine, which cannot seem to make a HEUI engine, in any market, whether passenger, heavy truck, or equipment that does not suffer from fuel injection issues.