raleighdogguy wrote: I'm not an engineer by training, so for the engineers participating in this thread....
I read somewhere in my obsessive googling on this topic that the HPFP failures may in some way be related to low input pressure that is caused by the primary fuel pump. Is that at all a possibility?
At this stage, nothing can be ruled out.
There are very few cases of Bosch CP 4.x pump failures --- so the immediate question I have is whether you sorted out the pump failures into the right boxes. Do the examples you have specifically relate to the CP 4.x as opposed to different models?
Having said that, there is at least one case (Rickatic) where there is no evidence of Low Pressure Pump failure(I don't call it primary, because it really isn't).
The low pressure pump is electrical, and it is suppose to automatically turn off upon reaching peak pressure.
I need to check with Ford, but am pretty sure that there are two separate interlocks --- one via the fuel gauge, and the other via the Low Pressure Pump that basically stop the engine if the computer detects fuel tank level too low (risk of sucking air), or if the low pressure pump failed. That is to protect the entire fuel injection system from running dry.
Even if the low pressure pump intermittently failed...
It is possible for the High Pressure Fuel Pump to be starved of fuel --- but does that mean anything?
Less cooling and lubrication, for sure --- but catastrophic failure of the HPFP at just over 1,200 hours?
A bit far fetched... for now.
But keep looking.... nothing better than ideas at this stage.
The percentages listed previously seem to indicate that Ford has had at least 84 or so pump failures. It is still unclear if that is warranty pumps only...IMO...84 pumps is quite a few. Gm has a similar number
Regards
Ricatic
Debbie and Savannah the Wonderdachsund
2009 Big Horn 3055RL
2006 Chevrolet Silverado 3500 Dually LTX with the Gold Standard LBZ Engine and Allison Transmission
2011 F350 Lariat SRW CC SB 4WD 6.7 Diesel POS Gone Bye Bye
raleighdogguy wrote: I'm not an engineer by training, so for the engineers participating in this thread....
I read somewhere in my obsessive googling on this topic that the HPFP failures may in some way be related to low input pressure that is caused by the primary fuel pump. Is that at all a possibility?
GM uses the same CP4 HPFP without a lift pump if I'm not mistaken. At least they did in the 2010 CP3 days.
ricatic wrote: The percentages listed previously seem to indicate that Ford has had at least 84 or so pump failures. It is still unclear if that is warranty pumps only...IMO...84 pumps is quite a few. Gm has a similar number
Regards
84 pumps is not a huge number relative to the number of vehicles on the road.
What concerns me is not the absolute number, but whether it is indicative of the potential for additional (larger) numbers of failures down the road.
Another concern is the consequential damage --- stopping a vehicle dead in the tracks for no apparent reason is a safety hazard if for no other reason being that you lose power brakes (upon exhaustion of boost reserve), power steering etc. which is potentially a much bigger deal than $12000 in repair bills.
Finally, there is the larger issue that the auto industry (and Bosch in particular) put a lot of eggs into using high tech coatings to deliver the next generation of promises made to regulators, customers, etc.
Reviewing some of the Ford submissions to NHTSA, I have to say eyebrows were raised as to how often the fuel samples were collected (annually), how little information on their sampling methodology, and how little (or none) work they did with the makers of additives.
I have to say I am not trilled by the lack of documentation as to how Ford (and Bosch if and when they respond to NHTSA)is working with the petroleum industry.
Really need to see submissions from American Petroleum Institute and its members, the biofuel Association / members.
What about the Additive makers?
Or.. the back yard modders and others that put stuff in their diesel tank?
The evidence is piling up that Bosch / Ford greatly underestimated the fuel purity issue.
NewsW wrote: 84 pumps is not a huge number relative to the number of vehicles on the road.
By way of comparison, the toyota Camry and Rav4 are currently being investigated for 6 incidences of door fires out of 830,000 vehicles. That's ~0.007 failures per 1,000 vehicles compared to the Ford/GM ~0.6 pump failures per 1,000 vehicles.
----
I guess one thing on my mind is how do we get more information? Are these appendices and databases referenced in the manufacturer letters available via a freedom of information request? If so, should one of us obtain them?
I guess one thing on my mind is how do we get more information? Are these appendices and databases referenced in the manufacturer letters available via a freedom of information request? If so, should one of us obtain them?
At this juncture, if you are interested, you can always zing a FOIA request and see what they say is available.
But my guess is Ford is as much in the dark about this issue as all of us are.
The party that knows.. Bosch.. is not in the picture.
I suspect even Bosch don't quite know the reasons for the failure.
Freedom of info act is for public entities...can a publicly traded corporation be
deems a public entity? Think it is meant for governmental entities, but someone
would need to check out the specific language and have an expert in those matter
offer an opinion.
I think public stuff is NOT as highly regulated as industrial stuff, or at least
when I was in that field. OHSA was MUCH stronger back then too
We can thank our legislators for doing what the insurance lobbyists paid them
to do..weaken the laws and jury awards for wrongful death/maiming....therefore
less of a big win against these OEMs...remember they are run by bean counters
who mainly only manage to the quarterly bottom line...very short sighted and
a horizon of just a few quarters
NHSTA is our watch dog agency, but they have been weakened by decades of political
appointments...mainly non-techie bean counters....lobbyists anyone?
Am not a diesel guy, but a boy racer/gear head from my teens who loves design
This has got my interest, but you guys lose me quickly down in this rathole
as I do NOT know the various components
I'll stick to the 30K view with a few dives down the rathole
Like I always ask why the need for exotic and expensive whatever..but..will say
I've had to many times. First time was for a disc brake in a steel mill that
constantly had the caliper slide pins corrode (GE, Westinghouse were the suppliers)
Re-designed to have our own designed brakes and though okay with the
higher alloy and plated pins (IIRC, around 1" in dia and about 12" long)
Found a cold application dry lube (Diversified Dry Lube out of
Tulsa). In-expensive, cold application process so didn't affect the temper.
Ditto when I noticed that all of the military spec'd stuff required
MolyB filled lube (fluid, grease, etc) especially in weightless
conditions. My ME knew of it, but didn't know much more. Back in the
60's, so no good Internet yet (just DarpaNet). Now use MolyB additive
in everything I lube.
So, back to this and my question of why the need for this exotic coating. Why
the extremely delicate processes?
Is the space to decrease the contact PSI not there? or is management dictating
sticking with whatever form factor for the sake of saving some $$$
This is academic for me, as was interested in switching to diesel.
Read up back in the 90's and stopped after finding out that there was
a freight train(s) coming down. Both the ever increasing HP
race/demand and the regulatory over head...married to e greater
than their sum
Wonder if the aftermarket OEMs have different solutions? Know warranty will be
an issue, but once a solution found, droves will go there.
If I had the money, I'd rig up several with some other pump (gear)
and run it till it broke or long enough to develop comparison info
The PSI is not that high per say, but it is for automotive. The temps
are also not that high, but for auto it might be. Saying that there
are solutions out there...maybe not in this small of a form factor, but
they are out there. Heavens, these are trucks, so there should be
room for a bigger/different/etc pump
Is there a clean sheet solution discussion out there? As I see several
band aids on top band aids on this one
BenK wrote: Freedom of info act is for public entities...can a publicly traded corporation be
deems a public entity? Think it is meant for governmental entities, but someone
would need to check out the specific language and have an expert in those matter
offer an opinion.
Actually, in this case the FOIA would be directed to the NHTSA ODI for the records of their investigation, not to the vehicle manufactures themselves.
My Son is a BMW mechanic, I think these pumps are the same design as the ones used on their Direct Injection gas Motors. He has replaced a bunch of those. They still have not solved the problem with them as of yet. They are also Bosch pumps. The pressure are also very high in the gas applications. He says some of it the the US gas with ethanol. He also has seen some pumps fail on their diesels.
1997 Ford F250 Extended Cab, 7.3 Diesel, 8 foot bed.
Reese 16K Hitch
(Moved into Shed) Hensley Arrow
Jordan Brake Controller, Hensley TruControl Gold Shelved.
Open Range 5th Wheel, Roamer RF392 BHS
Trail-Mate wrote: My Son is a BMW mechanic, I think these pumps are the same design as the ones used on their Direct Injection gas Motors. He has replaced a bunch of those. They still have not solved the problem with them as of yet. They are also Bosch pumps. The pressure are also very high in the gas applications. He says some of it the the US gas with ethanol. He also has seen some pumps fail on their diesels.
Peak pressures of gasoline direct injection is now around 350 bars.
That is, 5,100 psi vs. 2,000 bars for the Bosch CP 4 pump, or 30,000 psi.
Roughly 1/6 the pressure.
Higher pressures in a diesel is needed because of the higher viscosity of diesel fuel and the need to break up the fuel into tiny droplets that combust readily.
Offline
