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My HPFP in Bank 1 needs to be replaced, I ordered the part and bmwoem1 is going to be replacing it.

The car never stalled, only thing I notice is a long crank in the morning, other than that the car runs fine.

I was thinking to sell the faulty HPFP on eBay (of course disclosing that it floods the fuel tank vent valves), but then thought if there is someone that rebuilds these, I would rather have it rebuilt and replace the HPFP in Bank 2 with the rebuilt one. Any thoughts? Thanks
 

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This is a great idea. I have identified someone I think is qualified, but it's a crapshoot as to whether they

1] can do it
2] will be motivated, since these pumps are extremely rare, and they won't get much business from figuring it out.

I plan to send at least one of my dead ones to him to see what he thinks. he might look it over and just say "nope, can't do it", in which case, I have a couple of other people in mind to try.

PM me and maybe we can coordinate. I'd rather have a single point of contact to him until he can comment on the possibility of succeeding, before he gets inundated with calls from people saying "hey, I heard you can rebuild my pump", which is not true yet.
 

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also, FWIW I had long crank in the morning, and stalling and gas forming in the tank vent tubing and choking my engine with gas, but you know what? I charged my battery up on an AGM charger and long cranking is a thing of the past, even though I still have all the other issues.

are you saying you had the pump replaced and long cranking went away completely?
 

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Disassembly Project

I picked up a used HPFP a couple months back and have been looking at disassembly recently. The reports of the fuel in the vent lines suggest that the diaphragm in the fuel
regulator at the top of the pump is leaking.

When you look at removal, you first notice the three security screws holding the regulator
to the HPFP casing, they are pentagonal-shaped. It might me a Bryce penta security bit
or something custom Bosch designed. At any rate, I ordered a pentagonal bit set from
the UK recently and the bit is too big so looks like I'm grinding a custom bit down to fit.

Hopefully will have some time this weekend to make the bit and go from there. We need
to find out what is causing these to fail as $2,500 per pump plus some fuel injectors and labor will brick these cars if a solution isn't found or BMW doesn't lower the price.

My theory so far, based on the research I've done, is the lower lubricity of gasoline may contribute to the piston scoring the bore which may drop aluminum debris to the injectors but the leakage past the diaphragm is a mystery so far, maybe the diaphragm is reacting with the ethanol over time, idk.
 

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you got any pictures of what you are seeing so far? I'd love to see. I planned to dissect one this weekend after I pull my motor, but you're way ahead of me. Great tip on the penta-screws. Nice heads up.

if it's lower lubricity in gas, is this a recent development for gasoline, or have we had lower lubricity chemistry for some time? (the theory reminds me of the nikasil issue)

also, was not aware of chronic N73 injector failures; as my car has 135K miles and original injectors and HPFPs. HPFPs just now failing. California car for the second half of it's life (first half: Maryland). We mix our own petrol. Not sure if that has to do with it?
 

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Not a five-point Torx security, think allen head but only five sides. The lubricity of gasoline has gone down with lower sulfur content. A lot of the sulfur is bound within aromatics and the process to remove sulfur also removes the aromatics which is great for lubrication; diesel is suffering from this as well. At the time the 760 was designed, 80ppm was present, now its down to 20ppm, at least in California.

I've been adding 3oz. of Stanadyne Lubricity to 15-gallons for the past five tanks as a precaution to try and ward off any lubricity issues, at least until more direct injection engines
become mainstream and they are forced to address the lubrication issue.
 

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yeah thanks. after I wrote that I went home and looked ay my HPFPs and had to think about the fact Allen is 6-sided.
 

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lower sulfur

Not a five-point Torx security, think allen head but only five sides. The lubricity of gasoline has gone down with lower sulfur content. A lot of the sulfur is bound within aromatics and the process to remove sulfur also removes the aromatics which is great for lubrication; diesel is suffering from this as well. At the time the 760 was designed, 80ppm was present, now its down to 20ppm, at least in California.

I've been adding 3oz. of Stanadyne Lubricity to 15-gallons for the past five tanks as a precaution to try and ward off any lubricity issues, at least until more direct injection engines
become mainstream and they are forced to address the lubrication issue.
yeah, I knew about the diesel. That's why I run B100 when I can get it for less than $5.00 a gallon, in my 7.3L PSD. I even keep a 275 gallon tote of it at home. Otherwise, I'll take B20 when I can get it.

There's a whole scam where the oil lobbies got California to halt underground storage of B99 until they can "study it", but the oil companies have no issue with B20 underground, to help them with their low-sulfur woes. They don't like the competition, but need Bio to help them sell fuel. Result: most of the small green bio stations went under. The wholesale business, where I get mine, sells to fleets who have above-ground storage, no doubt mixing it at their depots to make B10 or B20.

did not know about the gas, thanks for that. I have used lubes in alcohol injection systems before for the same reason. Will consider looking into the Stanadyne stuff. Thanks.
 

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that is a huge perforation. dang. and 120bar is about on par with the 8MPa I have read, revving to 6000 RPM on my 760 using DIS. (not under load, though). Idle is always 3 MPa on the high side.

it's interesting to note, just for our discussion, he mentions the pistons have their own oil supply. The return line from our pumps has that extra inline fuel filter under the car....? TIS says it is for oil-contaminated gas.
 

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Hey, do either of you folks have DIS?

if so, can you start doing a diagnosis request of the fuel pressure and measuring and writing down fuel pressure levels on DME 1 (high) and DME 2 (low side) for


pressure before start, after 8 hours or more (make sure you don't press the start button after inserting the key or it will put it in radio ready mode and pump up the low side) (this value is all over the board for me, on two different 760s)

pressure at idle once it settles down (on mine it's always 3 bar and 3 MPa)

pressure immediately after engine shut-down. (usually 0.7 bar and 0.7 MPa)
 

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Been searching around for this 5-sided allen as well. Read the blurb on this site. Maybe there's a reason it's not easy to find the tool

http://www.keyedlok.com/brycefastenerwebREVAMP/home.htm

>>>Why is the product better?
Penta-plus***8482; and Penta-nut***8482; are proprietary security drives that have a very select customer base. Customers are screened and access to screw drivers is limited.
>>>
 

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Bit needed for disassembly

Upon further inspection, looks like the bolt is a Ribe Pentagon security with each side measuring 1/8" (~3mm). I found a used high grade bolt in my garage from a seat removal
that should be great for the grinder, nice hex head, about 2" in length with the last 1/4" smoothed out.
 

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Fabricated a cardboard template of two sides of the pentagon, 1/8" side length, 108 degree angle using a protractor. Plan is to score a mark on the
high-grade bolt using the template and rotate the template around until the pentagon shape is made and then grind down the excess using a bench
grinder. I'll post pics this weekend.
 

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will it hold up?

Fabricated a cardboard template of two sides of the pentagon, 1/8" side length, 108 degree angle using a protractor. Plan is to score a mark on the
high-grade bolt using the template and rotate the template around until the pentagon shape is made and then grind down the excess using a bench
grinder. I'll post pics this weekend.
don;t you want to be modifying/grinding tool-steel for this application? in any case, great luck and keep us posted.

I am taking the day off, and pulling my greasy, oily, and apparently--blown head gasket--135K motor and trans out. When I removed the exhaust, the aftermarket cans I welded on had about a quart of water in them. Was not sweet-tasting, though, and not green. The water tank up top was only down by about a half quart or so, so I am not sure where it came from.

In any case, I am looking forward to getting the 50K wreck motor in there.
 

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my 135K motor is out, but I am on a rampage to get the 50K motor hooked up and running in my car. My efforts to get the pumps off and dissect one, and send one off to be inspected for possible rebuild, are going to wait a week.
 

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If it is a diaphragm issue is there something stopping an aftermarket pump being developed which will have a source for lubricant like a pressurized oil source to provide some type of lubricant (similar to a turbo) to the fuel pumps? Something stronger and a smarter system? Maybe it's a pile dream but I feel like these can be built to be foolproof. I only put this out there because I had to replace 2 of them and have one out of the box come defective out of the box (so that's 3 pumps while replacing 2.)I feel like there is a big market for aftermarket/performance developers if they can make a better than stock design for these pumps.
 

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MWS, my guess is the water you found was condensation. I was not aware that you were also dealing with a blown head gasket...or is that what you are thinking due to the wate in the exhaust?

Socalbaksh, I doubt any aftermarket company will bother with V12 parts as there is not a large enough market for the parts due to the small number (relatively) of V12's on the road. Just my guess. In comparison, my son's E46 is plentiful and many parts can be found aftermarket.
 
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