Fuel in oil

[Signature620]

That fuel line you speak of goes to the DPF injector block. If the spare IFSM doesnt have the fitting to screw the line onto it is probably from a CM870 and I'm pretty sure they have different fueling and timing actuators.

The groove in your existing IFSM is probably not an issue. That oring just keeps the oil in the head from leaking outside. It doesnt seal fuel in.

You should run the engine on dyed fuel in a bucket, not just put dye in the filter. That way you have much more time to see where it's going. Run supply and return lines into the bucket or most of the dye will just go out the return to the tanks.