I bench tested a couple of this exact same pump, which would produce in excess of 80 PSI on the bench in seconds as soon as you restrict flow. They may be high flow, but if you dead head them, they will pump up pretty high, close to 100 PSI.

Plus, on the powerstroke, with this pump, they have a spring loaded valve/pressure regulator that dumps excess pressure down the return line out the fuel filter before even getting to the fuel galleries, would a pump of this nature not be deadheaded used on an old mechanical diesel without a similar feature, or does the MB injection pump have something similar that would protect the electric pump from damage? Could you damage the injection pump with this type of over pressure also?

basically, my point is that even a heavily used pump out of a junkyard is still expensive and not the best choice for this, unless the mb has all the rest of the ford fuel delivery features designed to control the pump.

Plenty of people have used 15-18 psi carter pumps in this application without issue, which are way cheaper, and can be had with a basic nipple ready for a hose clamp, not a ford factory fuel line attachment.

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There is your key. Allow the pressure regulator to do its job and don't pinch off any of your fuel lines.

FYI, thats not how fuel pumps on engines are operated.

Do you have any understanding of whats actually in your car's fuel system? What do you call this:

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Im talking about something like the FR series on demand walbro pumps. The FR8 is only 12 PSI deadhead, but they have pretty decent flow, and best part is they shut off automatically and maintain certain pressures.
http://wem.walbro.com/distributors/frpump.htm

There are also carter and bosch high pressure pumps for a powerstroke available.

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Instead of being rude, if you read what I wrote, you may be able to understand that I asked a question. Lets review, shall we?

I said- would a pump of this nature not be deadheaded used on an old mechanical diesel without a similar feature, or does the MB injection pump have something similar that would protect the electric pump from damage? Could you damage the injection pump with this type of over pressure also?

The answer to my question would be from your information, yes, there is a fuel pressure regulation device that may be up to working with this high pressure ford pump.

so the next question would be, can it handle a pump that is rated for a much higher pressure, will it bleed off fast enough since its usually dealing with 10-30 psi?

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That pump is completely inadequate for your engine. Fuel pressure is 12psi (0.8bar) minimum, there is no maximum specified by Mercedes. To get rated performance, maximum fuel economy and adequate injection pump cooling the fuel pressure needs to be at least 20-30psi at full engine power.

There is no need, its very simple; you lack understanding of how the fuel system works.

Look up document 07.1-145 (Checking fuel pump and bypass valve) and go from there.

Not surprisingly, you are missing what I am getting at. You have a fuel pressure regulation device designed to work with a mechanical lift pump that fluctuates from 5-30 psi based on age and engine speed, yes?

Then you bypass that low psi mechanical pump, and put in a much higher pressure pump, can the fuel pressure regulator keep up with it?

That is the core element of my question. Would it restrict the flow, and cause the high pressure ford pump to start to build up in pressure, creating a possible leak situation, or potential damage to something?

Its an expensive pump, why do it is my point? lots of other options

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No. Thats not how regulators work.

Yes. Thats how all regulators work.

No. There is nothing that can leak or be damaged by the factory 30psi operating pressure.

I get electric fuel pumps at the salvage yard for $14.00 each.

A 30 psi lift pump is the highest pressure I am willing to install.

In an emergency, anything that works is OK.


http://www.ebay.com/sch/i.html?_nkw=fuel+pump+12v&_sacat=0&_odkw=fuel+pump+15psi&_osacat=0&_trksid=p3286.c0.m270.l1313

http://www.harborfreight.com/12-volt-marine-utility-pump-9576.html

lol, and you lack the ability to express yourself in a non abrasive manner.

Heres what I understand, obviously never having done it, you would suggest that the op take an expensive, high pressure, specific application pump and use it to replace a far lower pressure pump when there are tons of cheaper options.

There are people on this very thread who have used and recommend a a lower psi carter pump, having done it with success. Im one of them.

If you go in and ask for a fuel pump for a 1996 chevy truck with the 6.5 a the parts counter, you will end up with the perfect carter pump for this emergency application, and it will be 30-60 bucks new. The only thing you will need to do is rig up fittings for either end.

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so using your logic, the fuel pressure regulation device on a cummins N-14, and the one on a lawn mower are the same? Any regulator will work in any situation?

I think my question was pretty simple, would it actually work using something designed for a much higher demand?, and obviously you don't really know, or you would say so vs being rude.

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of possible interest to this discussion, heres a video of a 617 lift pump output pressure-

http://www.youtube.com/watch?v=narBhZQLCg8

Its on a higher mileage engine, but there was as yet no power loss. The pump would jump between 8 and 25 depending on demand

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So? If you were willing to learn instead of backtalking things would go much nicer.

No. Again, you're not understanding the situation or the fuel system operation.

Congratulations, you installed a cheap fail-prone pump. I'm happy for you.
People that build/modify things with longevity and knowledge of the fuel system's needs in mind will look for something that does the job.

There is your problem. The 6.5 is a pile of garbage. A stock OM617 makes only 30% less power with 55% less displacement (57% more HP per CI) 15 years before the 6.5 was ever on paper.

No. The N14 and push lawn mowers do not use external pressure regulators. An N14 controls the entire injection process by fuel pressure (PT system), the throttle directly controls the fuel pressure. Lawn mower fuel pressure is controlled by the carb's float and gravity.

Thats because he is using a cheap non-dampened (fluid filled) gauge.

Please link to the dyno sheet showing his vehicle's power output. Butt-DynoŽ is not a calibrated system.

who is comparing the 6.5 to the OM617 and why? Stop making a habit out of missing the point.

The 6.5 uses a 10-20 psi electric lift pump, therefore if you go into a parts store looking for a cheap electric emergency pump that will work, requesting that vehicle and engine option will get you a pump that has a very similar output and would work in this application.

What the engine is and why compared to the OM617 is pointless. If a 2.0 gas powered ford escort used a 12 volt lift pump that had similar specs to the mechanical lift pump on the diesels, I would also suggest that vehicle.

Finding your way through the density of parts counter personnel at auto stores is why I brought up the 6.5. You are feeding them info that will arrive at the part that you can use.

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Learn what? that a poor suggestion by you cannot be discussed without you switching into an infant? Backtalking? Im sorry, I forgot that you were viewed with such awed respect on the forum, your eminence.

I think a powerstroke high pressure pump is the worst choice of all 12 volt pumps you could possibly find out there for someone to install in an emergency, and in any other situation.

The reasons why is its just plain wrong as far as specs, and just too expensive to play with.

You have not brought up any reasons why it would be a good idea other than flow, and your hatred of the carter pumps, based on what?

You apparently have no experience installing either on your benz, correct?

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