Ford's answers to the NHTSA 6.7 Investigation

durallymax wrote:
snip...

The CP4 pump is timed so that its pulses match up with injection events.

A pressure regulator is still mounted on the pump but an additional one was added to control how much fuel is bled off into the return system from the high pressure system. Essentially replacing the fuel pressure relief valve.
snip...

Was going to ask what 'timing' meant, but this solves that and goes
to both confirm and tell-tale that they are aware of the pressure waves
we have been discussing

BUT how can ONE pump (single or even twin piston) be timed with
8 injectors? Then the secondary/tertiary/etc harmonics?...or are they
so low as to be noise?

Is there a sensor on the pump shaft vs the ECU or whatever is controlling
the injection system to allow them to sync? AKA...cam sensor for
ignition control


My controls DB hairs raised reading that there are *TWO* regulators
and/or relief valves to the return?!?!?

A huge tell-tale that they had a problem, chased it and solved it to
some level of confidence with the addition of another set of regulators/valves

Not good engineering, IMHO...worse if there is a 3rd set.

Marry that with the open question of whether there is/are any plenum/accumulator

That deals with pressure waves backfeeding to the piston chamber

Back to the piston chamber...am convinced there is cavitation issue(s)

Back to the lube and chamber for the shaft/cam/lifter and the shaft
bearing (it should be needle and hope large enough, as have seen too
many go too small dia needles) and the shaft seal.

Think a multitude of issues that are multiplexing.

H2O intrusion from the fuel (both raw H2O and emulsified) and now think
one mystery solved...must be or highly likely the pump shaft bearing
seal

Where does the pump shaft/cam/bearing lube go to after lubing that area?

Does it go back to the tank via the return line? Or becomes directly
the next intake for the piston?

Just have to find time to read up that article NewsW sent me on organic amines.