Anyone using an electric aux. lift pump?

[Lowflyingbird]

I have a 96 E300 606, I have already done the plastic lines, viton O rings, tank strainer, pre filter strainer, and filter. As expected it takes forever to crank the motor enough to get the fuel to fill everything to start. Currently batteries are dead and being charged. Has anyone installed an electric lift pump to aid? If so what did you end up using? I'm considering a Purolator 4-7 psi universal, the new plastic body type. I know it works better as a pusher pump mounted low for priming purposes, near the tank. I'd prefer to mount where the metal fuel line enters the engine bay at the point where the rubber hose connects going to the engine.
Thoughts...

[Jeremy5848]

When you changed the primary filter, did you remember to put a new o-ring on the new primary? New primary filters don't come with o-rings, they have to be purchased separately.

If not that, it sounds like an air leak somewhere in the fuel system. I have never had the problem you describe with my '96 E300D.

Jeremy

[ROLLGUY]

If you install an electric pump just to prime the system after opening it up, it should not be needed for normal operation. If the engine will only run with the pump operating, you have a lift pump problem. I installed an electric pump on my Mitsubishi truck for priming and for when the pre-filter gets clogged. When the power drops, I switch on the pump and it gets me to where I can safely change the pre-filter. The factory lift pump works fine, but the electric pump on a switch helps when I get a dirty tank of fuel (only happened once so far). It is also nice to have in case a lift pump does go bad. I use a pump from Master (manufacturer). It is about $60.00 and is made for Diesel.

[Lowflyingbird]

The mech. lift pump could be weak? I know that when changing filters it takes alot of additional cranking to fill the new filter and lines back with diesel. My battery was charged, but ran weak after all the cranking. I have heard of people installing electric lift pumps is to aid the system, it seems like a good idea. I wanted to hear from anyone who did it, what their opinion is. I'm well aware of the 606 issues with air in the lines. After changing all lines and O-rings I still found air at the first clear line from the thermostat (heater) to the pre filter (strainer). I now changed the rubber hose which connects the thermostat to the metal fuel line entering the engine bay. I thought that the rubber hose might be the source of air entering the system before the fuel even gets to the motor. I plan on getting an additional fuel filter/strainer on that line which I can see into. Note: I eliminated the intank strainer when I pulled my tank out to clean.

[Diesel911]

Looks like another fix it so it works like it is supposed to or do a patch job questions.

You could also rebuild your Fuel Supply/Lift Pump.

OM606 Fuel Pump Rebuild

[biopete]

Originally Posted by Diesel911

Looks like another fix it so it works like it is supposed to or do a patch job questions.

You could also rebuild your Fuel Supply/Lift Pump.

OM606 Fuel Pump Rebuild

Are you saying a new lift pump primes the system faster? The thread just mentions that it fixed a fuel leak.

I hate not being able to prime the system without running your battery down. It's really a pain when you run out of gas. I just expect to have to have a jump when i run out of gas in my W124s. None of them have ever primed the system fast enough. An electric lift pump is a very nice addition to the fuel system i think. Especially if it doesn't restrict flow if its not on.


When you change your fuel filter, dump the fuel in the old filter into the new one and you can start up and rev it up without too much trouble. Just keep it revving initially while it chokes the air out.

[ROLLGUY]

Originally Posted by biopete

When you change your fuel filter, dump the fuel in the old filter into the new one and you can start up and rev it up without too much trouble. Just keep it revving initially while it chokes the air out.

Not a smart thing to do!!! By dumping the fuel from the old (dirty filter) into the new, you will also be dumping the dirt that the old filter trapped from getting into your injection pump and injectors. I have heard that filling the filter with ATF will aid in cleaning the injectors and help prime the system.

[compress ignite]

EXCEPT: ATF burned for fuel in a Pre-Chamber Diesel.
It leaves burned residue behind to clog up the pre-chamber.
AND ATF isn't produced/chemically engineered to "Burn",There's some
stuff in ATF that Morphs into Nasty compounds when burned.

[ROLLGUY]

Originally Posted by compress ignite

EXCEPT: ATF burned for fuel in a Pre-Chamber Diesel.
It leaves burned residue behind to clog up the pre-chamber.
AND ATF isn't produced/chemically engineered to "Burn",There's some
stuff in ATF that Morphs into Nasty compounds when burned.

Or one could use just pump Diesel. I have heard the ATF "purge" being done by the old timers for years.

[oldsinner111]

I use one in my SD for higher fuel mileage and simply just blow away cars up mountains.I use a universal 10 psi inline pump to push diesel/WVO to engine.
I dicovered during runs with full tank after burning lets say 4 gals.because fuel gravity was higher,fuel pressure was greater,that MPGs were greater.Than runs down to 4 gal to empty.
I'd like to add that the inline pumps fault open incase power is lost,that way your lift pump can pull fuel.Also I believe with a boost pump the engine does'nt have to work pumping its fuel.

[Diesel911]

Originally Posted by biopete

Are you saying a new lift pump primes the system faster? The thread just mentions that it fixed a fuel leak.

I hate not being able to prime the system without running your battery down. It's really a pain when you run out of gas. I just expect to have to have a jump when i run out of gas in my W124s. None of them have ever primed the system fast enough. An electric lift pump is a very nice addition to the fuel system i think. Especially if it doesn't restrict flow if its not on.


When you change your fuel filter, dump the fuel in the old filter into the new one and you can start up and rev it up without too much trouble. Just keep it revving initially while it chokes the air out.

If you Battery is of the right capacity and in good condition and you Filled the Fuel Filter when you installed it your IP/Lift Pump system are supposed to be able to bleed the Air out. If it is failing I would suspect something wrong with the Battery or the Lift Pump.

My thought is that if the Stock Fuel Supply/Lift Pump is not bleeding the system fast enough that there could be a problem with the Pump itself; that might be cured by rebuilding the Lift Pump.

But, the only way to know that is to rebuild the Lift Pump and see what happens or take the time to make a setup to test the Lift Pump to see if it is functioning OK.

The reason for the above is that I do not believe a 7 psi Electric Fuel Pump will put out the needed Pressure of volume of Fuel.

It would be nice to have the Electric Fuel Pump for convenience sake after changing a Fuel Filter. But, for myself I would still want my Lift Pump to work properly.

If you wanted to go all Electric and eliminate the Lift Pump completely I believe you will be paying over $100 ($150?) for an Electric Pump that can do the job.

It could also be that the Air Bleed passage in the Pressure/Overflow Valve is plugged.

[Fattyman]

I use one of these and keep it running all the time.
If you don't have anything to prime the filter with you just leave it loose and let the pump fill it up. Done.

[ROLLGUY]

Originally Posted by Fattyman

I use one of these and keep it running all the time.
If you don't have anything to prime the filter with you just leave it loose and let the pump fill it up. Done.

That is the exact pump I use as well. I wire it to a switch to turn it on when needed.

[Diesel911]

Originally Posted by Fattyman

I use one of these and keep it running all the time.
If you don't have anything to prime the filter with you just leave it loose and let the pump fill it up. Done.

If it works it works.
But, the Fuel Injection pumps on the 84 and 83 Mercedes you have listed do not have the self bleeding feature like the OPs IP does.

[Diesel911]

The guy with the 83 CD said this electric Fuel Pump worked for him. But, this it not the same year and model as the OPs.
http://www.benzworld.org/forums/w123-e-ce-d-cd-td/1474392-electric-fuel-pump.html