Ford's answers to the NHTSA 6.7 Investigation

Just in for a quick, late lunch and out again...

Ask if anyone knows or can work up that HPFP cross section with
references to the acronyms in the posts below. As I need to be sure
of which is which

Right now, I'd just say they went over board trying to NOT have a
good accumulator. An ultimate Rube Goldberg design and wonder if
dictated by bean counter management (both engineering and others)
who didn't like the cost of a good and proper accumulator????

Initially thought that they created cavitation potential whenever
that metering piston is actuated by that piezo stack

Think can see why they did it that way and for me, goes to poor
architecture. Meaning no accumulator with a relief/bypass back to the
fuel tank 'up there' at the accumulator

That then goes back to the need for timing, which could be again
solved by a good accumulator design

The piston does not show any locking mechanism to the roller follower
assembly.

Questions more after realizing that there is a one way valve on the
top of the cylinder. Why the metering valve?

Why such poor fluid (fuel, coolant, and lube) within the shaft/cam
cavity? Wonder if they thought the up and down motion of the follower
would 'pump' it, along with the rotational paddling of the cam...but
if that diagram is to scale with accuracy, then the intake port is
way too close to the exhaust port. Another again, why is there a 3rd
and smaller port that leads to the return line?

First blush with these new diagrams/thoughts thereof...solution to this
whole mess is to install a properly designed accumulator.

Change the pump to a constant speed pump, NO TIMING, with one way
valves for intake and exhaust.

Change the way the pump crank/cam cavity is lubed by moving the intake
and exhaust ports 180* apart to have 'real' pumping both by fuel flow
to the injectors/return and the follower/cam. Right now it has recycled,
back water lube/coolant that then becomes stagnate & possible debris
filled. Minimally reduced lube qualities as it is recycled and gaining
in temp. Refreshed a 'bit' by new fluid that sneaks out of the flow
into the exhaust port

The return line should then be at the accumulator.

This way the pump would see no wacky intake fluctuations from that
metering piston, it's not there.

The output is into the accumulator, so it is softened up to some
preset determined by the accumulator and return valve.

Any shock from the injectors is attenuated by the accumulator

The emissions is kept the same, as I only see the atomization at
the injectors as the key.

Engine braking or deceleration has no effect on the pump, as it is a
constant speed/volume/PSI feeding into a proper accumulator that then
returns any excess flow.

So, can someone apply the acronyms to the proper components on that
cross section?

NewsW wrote:

stsmark wrote:

During acceleration, the VCV and PCV are commanded to meet the driver’s demand (accelerator pedal input/engine
load). The PCM’s commands to the VCV and PCV are based upon: FRT, ECT, EOT, ATT, engine load, and regeneration
state.
On deceleration, the VCV is closed and the PCV is opening to max position to reduce fuel pressure. When RPM is
approaching the desired idle speed, the VCV begins to open to prepare for injector usage.
During regeneration, the left side injectors perform post injection. The right side injectors do not provide fuel for
regeneration because right side cylinders supply exhaust gas to the EGR valve and EGR cooler.
Under certain conditions, like battery disconnect and fuel system reset, the fuel system operates in Adaptive PCV (APCV)
mode on the first start. In the APVC mode, the PCM is learning the duty cycle needed for the PCV to achieve the desired
fuel pressure.

I have always wondered if the Volume Control Valve has been a piece of the puzzle. Also don't forget that these engines can be spinning 3500- 4000 rpm in Engine Brake mode with the VCV closed on a good downhill while towing.

To answer a few on going questions,
The HPFP is gear timed to injection events for pressure stability.
There is an area in the left fuel rail which acts as a damper for pulses. Left rail feeds the right rail.
The inlet fuel pressure is regulated to 100 psi from the DFCM pump.

From day one I felt the corrosion shown in some pictures of the fuel system parts was caused by the acids in Bio firing off the mild steel of the fasteners etc. I wonder if some of the deposits in the rails shown by Ford are actually the lacquer discussed in some of the papers and not corrosion.

I would love to see pictures of Ricatic's pump carnage, I imagine he has something which is keeping him from posting them.

As far as counting the odds, imagine what the odds are on a husband and wife both being diagnosed with MS 12 years apart. A virtual Father of Modern Neurology at the Mayo in Rochester guessed in the billions, but it is my reality. Pardon me if I hesitate to gamble.

I really have had my truck be trouble free and like it alot, but a 10-15k hit means no meds for a while at 1208.00 a month, not pretty. The fact that the failures are so rare is even more frustrating as to why Ford won't belly up to the bar.

This is the Achilles heel for these trucks.

Mark

Thanks for the info.

highlighted points for ben etc. which feeds into his pump fluid dynamics / cavitation stuff.

I am waiting on raleigh to help us with some sensor / software issues and hence will not comment on the adaptive routine -- which is an issue I am pursuing.

Would be real helpful if some pairs of eyes look at pics of the "corrosion" used b Ford and compare with the corrosion of steel by biodiesel metabolites I posted.


A note about odds:

The chance of a Ford catching fire from the improperly designed cruise control deactivation switch is well below the rate for HPFP failures.

Ford recalled all 14 million of them...

If your neighbor becomes unemployed, it is "just a small chance", and 97% of the work force remains employed.

If you become unemployed, it is the Great Depression.