Lift Pump/Prime pump

[WMO Madness]

I finally had the minute to install the electric fuel pump before the primary filter. Is the lift pump essentially some sort of pump but at a low rate to feed the I? after I install the electric fuel pump the car seem to start faster even if the glow plug light still on and it accel better. The pump is 10-14 psi both for gas and diesel. did I just override the lift pump?

[barry12345]

You may have increased the base pressure of the injection pump is my guess. Or the old lift pump was flowing poorly. Without a fuel pressure gauge for the base of the injection pump installed you have no ideal really except that things appear better.

The pressure in the base of the injection pump is determined by the supply pressure of the lift pump and the condition of the relief valve. Old semi obstructed filters can for example lower the operational pressure. Best for your vehicle is 19 pounds pressure but 14-16 is fine. Again you need a gauge to tell what you may have. Many have far less as the system has never been properly checked out.

[Doktor Bert]

barry, isn't 20-25 psi more like the target psi????

[WMO Madness]

Originally Posted by Doktor Bert

barry, isn't 20-25 psi more like the target psi????

WOW, you mean to tell me that lift pump has the capability to provide that much pressure. If the lift was not working properly, can it be replace so the IP has the proper pressure? The 1985 300SD has what appears to be a newer version, will that help increase the pressure.

[charmalu]

You can buy a new lift pump if you want, kind of pricy.

Here is a rebuild kit.

http://www.peachparts.com/shopforum/mercedes-parts-reference-library/327357-0000900210-om615-616-617-lift-pump-valve-kit.html

By newer version, are you refering to the black Primer Pump screwed into the Lift Pump?


Charlie

[Hit Man X]

Originally Posted by charmalu

You can buy a new lift pump if you want, kind of pricy.

Here is a rebuild kit.

http://www.peachparts.com/shopforum/mercedes-parts-reference-library/327357-0000900210-om615-616-617-lift-pump-valve-kit.html

By newer version, are you refering to the black Primer Pump screwed into the Lift Pump?


Charlie

Do you have the part number for that tiny oring that goes within the lift pump? I had the link opened to jot down and shut down the PC by accident.

[WMO Madness]

Originally Posted by charmalu

You can buy a new lift pump if you want, kind of pricy.

Here is a rebuild kit.

http://www.peachparts.com/shopforum/mercedes-parts-reference-library/327357-0000900210-om615-616-617-lift-pump-valve-kit.html

By newer version, are you refering to the black Primer Pump screwed into the Lift Pump?


Charlie

My apologies to everyone, I am working on 1984 300D. Yes I was talking about the one with black prime pump screwed into the lift pump. The 1985 300SD I got from a friend has one, but I think I will get a new one and replace the one in my car. I am still new to these cars so re-building one at this point is not an option. Of course unless they are a pricy as you say they are. Anyone give me the price for one and maybe the P/N? Thank you

[Diesel911]

Originally Posted by WMO Madness

My apologies to everyone, I am working on 1984 300D. Yes I was talking about the one with black prime pump screwed into the lift pump. The 1985 300SD I got from a friend has one, but I think I will get a new one and replace the one in my car. I am still new to these cars so re-building one at this point is not an option. Of course unless they are a pricy as you say they are. Anyone give me the price for one and maybe the P/N? Thank you

Pelican Parts; look there.
Often if you look up Primer Pump it takes you to the whole Fuel Supply/Lift Pump. They are somewhere between $100and $200 New.

I randomly grabbed the below stuff from My Notes; don't know if it all applys or not.
Lift Pump, Fuel Supply Pump rebuild kit
http://www.peachparts.com/shopforum/showthread.php?p=2284880#post2284880
Lift Pump, Fuel Supply Pump about sanding the Valves has the small O-ring size
http://www.peachparts.com/shopforum/showthread.php?t=266857&highlight=lift+pump+kit

Fuel Supply Lift Pump showing how I put it into the vice.
http://www.peachparts.com/shopforum/showthread.php?t=266857&highlight=lift+pump+kit

Fuel Supply Lift Pump Rebuild.
http://www.peachparts.com/shopforum/showthread.php?t=266857&highlight=lift+pump+kit

Lift/FUEL SUPPLY PUMP TINY o-ring
Bosch lists now 2 440 210 002 (MB 010 997 86 48) as replacement to the original black(perbunan?). And yes,the replacement is Viton.
The 5mmŲ x 1.50mmŲ 'O' ring is located in a groove in this bore and prevents engine oil in the IP from being sucked into the fuel re-circulation circuit. In most cases this O-ring has either hardened and broken up or completely disappeared.


If you get a Fuel Supply/Lift Pump kit from a Fuel Injection Shop it will likely be more complete (there is a model plate on yout Lift Pump with the Numbers):
Bosch Fuel Supply lift pump kits
http://www.peachparts.com/shopforum/showthread.php?t=215770
Bosch FP/K22MW22 Feed pump There is a repair kit for these pumps. Bosch part number DGK301 The kit covers FP?K KE and KS pumps includes more parts than you'll need to rebuild your pump includes springs, copper crush washers, piston seal and check valves. Also included in the kit is the mounting gasket. There is a sediment bowl and prefilter cartridge included in the kit for other applications. Some of these pumps are used in heavy equipment and in the aviation industry. I got my kit overnight from a diesel injection shop I used in the past. Hope this makes the parts easier to track down. Price wise I got it for under $22.00 including shipping and local sales tax.
ROBERT BOSCH DGK301 6123 REPAIR KIT FP/K.KE.KS.FEEDPUMP From Saco
DGK301-4 8408 SERVICE KIT FP/K.(4 VALVE)
DGK301-H 2362 REPAIR KIT FP/K...FEED PUMP

[ah-kay]

Originally Posted by WMO Madness

after I install the electric fuel pump the car seem to start faster even if the glow plug light still on and it accel better.

It is all in your mind. The injector stills opens at 135bar.

[Stretch]

I can't tell which car you have WMO - can you (pretty please) stick some information about that in your posts or your signature? 'Cos I for one can't remember which car everyone here has!

If you want to see what a lift pump is like in bits then have a look here =>

http://www.peachparts.com/shopforum/diesel-discussion/294499-refreshing-fuel-pump-om617-european-spec-%96-non-turbo.html

It is unlikely to be the one on your car but it will be similar in many ways.

[Diesel911]

Barry has a point that under normal circumstances the Fuel Pressure Relief/Over Flow Valve controls the pressure; but, that is when it is working properly.

[ah-kay]

I think he meant looping a hose between the input and output ports. The residual fuel/diesel will be pumped around the pump and lubricate it. May be add a little bit of fuel to the hose if necessary.

[whunter]

Originally Posted by ah-kay

I think he meant looping a hose between the input and output ports. The residual fuel/diesel will be pumped around the pump and lubricate it. May be add a little bit of fuel to the hose if necessary.

That is correct.


.

[WMO Madness]

Originally Posted by whunter

That is correct.


.

My sincere apologies for dragging this on, but I want make sure I have the right deal for this "looping" techniques. Hopefully I've illustrateded it correctly in the attached photo, the only thing difference is the prime on my lift pump is on the outboard side vice the inboard side due to mine is an older version. If I am on the right track here, I will focus on this MOD tomorrow. Thank you for veryone's patient. Because ever since I've intalled this electric fuel pump the car runs smooth, accel better and starts faster.

[qwerty]

Originally Posted by WMO Madness

My sincere apologies for dragging this on, but I want make sure I have the right deal for this "looping" techniques.

Why waste horsepower driving a pump that does nothing useful? Remove the pump, fabricate a cover plate and be done with it.