Hi all,

Just wondering if anyone had fitted an electric fuel pump to feed the mechanical pump instead of using the standard mechanical lift pump?

I am looking into upgrading the elements at some point, but know that ensuring a good fuel supply - at perhaps increased fuel pressure - would help out performance overall even without upgraded elements.

I am guessing something like a low pressure fuel pump such as those used on carb'ed engines would work?

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UK spec Mercedes W210 E300 Turbodiesel wagon - OM606.962 with 722.6 transmission - rust free!

I have a wagon, and put a small walbro pump that pushes 30 psi to the mechanical pump.

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1982 300TDT
1991 190D
2022 Metris

GregMn has I believe, but only uses it to prime the IP when needed; EX..when changing fuel lines and such. I came a across a theory that because the OM606 pulls fuel through the lines it causes cavitation/bubbles which is a problem and its thought that a pump like you are thinking will help. AFAIK no one here has done it on a permanent basis.

OM606 air in the fuel lines: A theory

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Treetops
06 E320 CDI 127K Miles
87 300TD 231K Miles

99 E300 269K Miles-Sold

I have thought of it as a backup plan for when the lift pumps get hard to find or repair. There is one on ebay ~$35 that says "for gasoline or diesel", so I expect most gas ones would work. There is a common small one sold under many brands (Mr Gasket, etc) that has a solenoid that moves back & forth to pump. Simple and rugged, but can be a "rattler" depending on where you mount it. The problem with all is that you become dependant on the electrical system. I would tell my son, that if he wants to insure he makes it home, don't stop (bring a pee jar) and nothing will stop that diesel unless it fails or you run out of fuel.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

Carb'd fuel pumps will be in the 2-4psi range, the IP needs ~15psi. It could absolutely be done, you'd need an EFI fuel pump to reach the appropriate pressure, and an adjustable fuel pressure regulator on the output side of the IP.

Most vehicles on the road use an electric fuel pump, I would not consider this to be a serious degradation of reliability.

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617 swapped Toyota Pickup, 22-24 MPG, 50k miles on swap

this one is sweet
AirDog Raptor Fuel Pump 100 GPH (R2SBD050)

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Current fleet
2006 E320 CDI
1992 300D - 5speed manual swapped

former members
1984 300D "Blues Mobile"

1978 300CD "El Toro"

Thanks for the help on this guys, I will look at some of the inline style pumps as a backup - perhaps to run when the boost level hits a certain amount to make sure the IP has all the fuel it needs.

I did notice on the older engines that the IP had a priming pump for when you do fuel filter or line changes, this seems to be missing on the later engines which is rather odd!

I am used to quite high spec pumps as I used to run a high power RX7, at 85% duty cycle on the injectors it would be injecting around 6.5 litres a minute - good job Bosch 044s were up to the job!

I do have a spare stock fuel pump from the RX7 which should work, but I will look to get an inline pump - wasn't sure the sorts of pressures I would need, I only know I wouldn't need huge pressure as its just pumping fuel from the tank to the lift pump.

I am tempted to look into creating an electrical alternative lift pump, perhaps using the OEM mechanical pump as an adapter and simply run a feed into it from the tank much like more modern diesels.

Will keep everyone posted on this - also looking at how to increase the internal pressure of the pump - I have seen some performance overflow valves which increase the internal pressure to help with filling the elements quicker.

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UK spec Mercedes W210 E300 Turbodiesel wagon - OM606.962 with 722.6 transmission - rust free!

I use a solenoid type electric pump on my International back hoe ( with a German Neuss D239 engine ) that looks like a fuel filter with 2 wires. These can be gotten in different pressures and gas / diesel. NAPA has them under the Carter brand , others brand it or make them as well. The are in the $ 40 range.

I have a Tennant ALTV ( mini street sweeper ) that uses a Kubota 3 cyl diesel, it has one of these pumps on it from the factory. Some of the light towers / welders I repair have these pumps as well.