Talking to cardinarky who has spent many years working in steel mills,i got a new perspective on the potential reason for failure in these hpfps...
While I fully support and am looking foreward to your modifications edith, the argument that perhaps there were some poorly produced batches of steel that are causing/will continue to cause failures... Well it seems to make sense to me. If the coatings on the parts in the pump were done poorly, there is a very good chance that there would be some sort of cover-up. I'm starting to get the idea that there isn't any good reason for 2009-2011 owners to have misfuelled or found bad fuel any more often than the rest of us.
I enjoy your posts.
I am nobody from Mississippi. I do not have 10 letters after my name (of all the degrees I have). Take all these comments with that understanding.
I am for a more robust pump. This robust pump also needs filtering that will take care of wear materials.
We face many needs:
1... Robust pump
Design, Materials, Workmanship
2... Fuel quality
Lubrication, Cetane, Additive package, Few Contaminants,
Fueling importance for folks that have never owned a diesel and especially a diesel that will self destruct with wrong fueling.
3... Warm up loop for fuel
Filtering for wear prone system, Screens for low wear system
4... Filtering.
Primary original fuel, Return fuel
The more wear prone the more filtering needed
I understand your point of shoddy materials. I also understand I have just dealt with / dealing with the PD engineering mistakes. Although VW has done an excellent job on their engines; there are a few glitches from time to time (I have my own glitches so I understand and have compassion) . The containment filtering of wear particles seems to be one problem area in the present CR system. Time will tell which: the metals / clearances / coatings / filtering / design are at fault, and order them in importance.
In the present system, a filter that stays super clean while the injection system eats itself alive is a little hint I am exploring. If one extra filter will contain most wear materials, the existing materials may wear better. Although opinions differ, the roller may be the first to suffer (at this point we have differences of opinion, and it may be different failures at different times).
There are differences in the older models and the CRs.
1... The total pressures expected out of the designs are different.
Older models have less pressure for a short time.
Newer models maintain a higher pressure over longer time.
2...The 1.6 injection pressure was lower and depends on the fuel for lubrication of the whole pump. The 1.9 ALH style is still low pressure compared to the PD and the CR.
3... The PD series has the roller injection assembly lubricated by engine oil and seems to work fine with high pressures. There are two phases of the injection pressure too. The unit injector lasts a long time too. This system seems not seem to shed excessive wear materials.
4... The CR has the higher pressures but has the roller assembly lubricated by ULSD. The roller assembly is also expected to work over a longer degree arc, produces high pressure from a lower RPM, Maintains this pressure. The CR pump is creating wear on the cam and roller assembly. The wear materials are not adequately filtered out (go through whole system).
No pump may be ever modified, but going through all this will educate us to the system. Very soon many cars will be out of warranty. We are encouraged to prepare for when the owner is to take care of his possible problems.
eddif