Anyone change out a "good" C7 injector pump

[jauguston]

10-30 is what it says in my engine owners manual. I had just not read that part before I talked to CAT Tech Support. In my manual its on page 105.

Jim

[glenn allen]

I have yet to read or hear about a HEUI injection failure NOT related to dirty oil.

Either fuel oil or engine oil.

What I have read about is operators/owners/shops who service Cat systems who are not paying attention and keeping dirt out of the fuel filter when it is changed.

And operators/owners/shops who try to stretch out the engine oil change time in a effort to save money.

Both or either of these will kill a HEUI injection system. Personally I like the system not because dirt kills them and it is a PITA to keep them clean enough to bring me comfort, but because the injectors can run fuel injection pressure up to around 35,000 PSI. This is a pressure that is unheard of in other injection systems. But remember liquid does not burn, it has to vaporize before it burns well and a gas (natural or LPG) burns the best of all except maybe hydrogen which is not generally available. So at 35,000 PSI pushing diesel through a fine nozzle will provide a cloud of extremely fine droplets and lead to a much cleaner burn. By the time you inject this fine cloud into a hot cylinder it vaporizes very fast. When you think about a fine nozzle think about the required 2 micron filter. Particles larger than this do not belong in the injection pump.

Others have said that a diesel cannot burn lean but I have read my ECM when it has recorded a lean condition. I found it related to a pluged 2 micron fuel filter. I have seen and repaired a lean burn diesel engine.

When I was done I was surprised that the pump did not suck the guts out of the filter cartridge and try to ingest the dirt that was plugging the filter. End of this is that the final 2 micron filter on my 3126 is and always will be a Cat filter. I have installed a prefilter and it can be from any maker so long as the final filter is Cat.

The injection pump does not mix engine oil and fuel oil together and engine oil is never supposed to reach the nozzle. If this happens then there is a defective injector. As soon as it tries to inject any engine oil the particles in the engine oil is larger than the nozzle and you not only have a defective injector but now you have a plugged injector nozzle.