Injector Pop Pressure

[Charlie]

Hi All:

I have finally got around to pulling the injectors off of my Yanmar 4JH4E. It has been creating oil for a while now and I think that I may have found the answer. Two of the injectors have a pronounced drip. It may be possible that the diesel fuel is slipping by the rings and going into the lubricating oil.

The thing that is really throwing me is the pop pressure. I have 3 that are popping at around 2100 PSI and one that goes over 3000PSI w/o popping. The manual says that they should pop at 21.1 - 22.1 MPa or 215 - 225 kgf/cm^2. 21.1 MPa translates into 3060 psi. My pop tester only goes up to 3000 PSI. I imagine I could get a new gauge that would read higher (and would be more accurate). The spray pattern on all of them looks good and the fuel is atomizing nicely.

The engine seemed to be running fine. There is quite a bit of carbon build up on the tips so I am going to take them apart and soak them in carb cleaner but I was wondering if anyone knew whether I am misinterpreting the pop pressure.

[Charlie]

bump this is