Kent over at Mercedes Source recommends a Walpro unit.

Am wondering about owners' experiences?

I removed the mechanical lift pump so I can use the cavity to return oil to the crankcase from the centrifuge oil filter and replaced it with an 10-15 psi electric fuel pump. Works great, this is on a 1984 300D.

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1984 300D, 1972 LT1 Corvette, 2014 Artic White 3LT/Z51 C7, 2013 650i Convertible BMW, 1994 Kawasaki Vulcan, 1992 Yamaha Seca II and 1996 Dodge Ram 2500.

I had one to push diesel,and veggie.Lost a contract don't have money to replace a new one
Though mine lasted 1 year,the Walbro unit break down also.There only one pump built for veggie and its a FASS

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1999 w140, quit voting to old, and to old to fight, a god damned veteran

I use a Carter electric pump that is mounted in the truck. I think it's rated at 18psi. Works great. Took me a while to find a good pre filter. The paper filters had a tendency to collapse and restrict flow.

I used the small 100 micron pre-filter from this site. Works great and is can be back flushed to clean.

RobbMc Performance Products - Fuel Filters

I have an 82 300SD

I am using a Ford horizontal fuel conditioning unit (HFCU). I found a few at the local scrap yard for 5 bucks ea. This is the fuel pump found on Ford Powerstroke 6.0 trucks. This unit is nice because it comes with a 10 micron primary filter, a thermostatically controlled fuel heater, a pressure regulator, and a drain plug. It is designed to deliver 50-60 psi, but works just as well at lower pressures. The unit is quiet and draws about 3 amps.

t

Is there an advantage of using one for pump diesel?

An electric pump makes priming the lines a breeze

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

this i find very interesting.....so all i have to do is pull such a unit at the pick and pull yard, and hook up fuel lines and 12 volts + mount it, or is it more complicated than that ??

like i said, highly interesting...

i would like to more...

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-Justin

I believe in extreme automotive perfection whenever possible.......there is no such thing as "It doesn't matter" !!!

1985 300 CDT - 287k miles

1980 240 D - 340k miles

With extras !!

http://facebook.com/BenzDieselTuner

http://facebook.com/SWFLAlternativeFuelsClub

http://facebook.com/SWFLBenzClub

http://SWFLBenzClub.com

That sounds about right for a fuel pump

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

Most Walbro "external" fuel pumps I know of are for higher pressure fuel injection ~55 psig. They will work at lower pressure, but much more flow than needed. Biggest disadvantage is they need a regulator and return line to the tank.

All you should need is a simple "carburetor" type fuel pump. They need no regulator nor return line and can run all day dead-headed. Most output ~6 psi, but you can get special racing types ones up to 15 psi (Holley blue pump). Some make a racket if you mount on a rear frame rail. I would try to mount in the engine bay, below the supply tube. There is a small one on ebay ~$35 that says "gas or diesel". For the most flow, get a radial vane type, like Holley or Carter.

Edit -
A few flaws above, that were pointed out in a PM by a reader. There is already a 30 psi regulator (or relief) valve built into the fuel plumbing, so any electric EFI fuel pump could use that. They won't be hurt by running at lower than normal output pressure and unlikely that diesel fuel would hurt one. Indeed, it might like the better lubrication. The Mercedes spec is 12 psi minimum from the lift pump to the injection pump, so not all basic carburetor type electric pumps would work. I know the Holley Blue Pump (radial vane) can be run at 20 psi with the larger bypass spring they offer since I used one for years to supply a Holley Pro-jection TBI on one of my classic gas cars. However, EFI pumps are smaller and have become even cheaper, so might be the way to go in replacing the mechanical lift pump.

There are 3 external EFI pump designs I know of:
Bosch for European cars - a bit hard to plumb w/ 1/2"D inlet and banjo fitting outlet, plus largest diameter
Ford truck type (80's & 90's V-8) - cheapest (<$50), only 5/16" tube fittings that I have seen
Walbro - similar size to Ford but 2x cost, higher volume, multitude of scew-in fittings available and mounting hardware

Hello,
The pump is called the HFCM, not the HFCU as I stated earlier.
I found the units cheap and local. I have seen them on ebay for over $400.00 - so you go with what you can find for a reasonable amount of $. If you have access to these cheap then try one. I took mine apart, cleaned it and made sure that the copper leads to the fuel pump on the inside of the pump were making good contact. I am using a length of 5/16" fuel line to connect it to both the supply and return lines. There are four nipples on this unit for main fuel in/out and return in/out.
Google "powerstroke 6.0 hfcm" for more info.
Here is a link to a diagram of the internal components and fuel flow.
275flow3.jpg photo by LowFlying7Three | Photobucket

Any why would you need an electric pump outside of bleeding lines which isnt that hard either? I mean, I know why you would, but I would be surprised if anyone in here really needed it.

__________________
http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

I rebuilt my lift pump as part of a general strategy to try and find the cause of a slight idle lope. I have noticed a little air in the fuel return line with the original pump as well as the electric pump, but I am beginning to think that a small amount of air is normal.

After replacing and balancing the injector nozzles (Monark), doing the valve lash adjustment, and replacing the rack damper, I am beginning to think that internal wear in the IP is the cause of the idle lope. The engine runs smoothly when off idle or under load.

I am also thinking about building a WVO system for this car, and a powerful electric pump is important for this.

Does the mechanical pump fail to provide enough fuel? Doesnt the over pressure valve regulate vibrations?

__________________
http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

And who's running a modified pump?

__________________
http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42