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1975 450 SEL restoration

Started by McGhee5120, 04 July 2022, 01:34 PM

McGhee5120

Great,
 Then I can clean up the dampener, and I will recheck the pump specs I purchased to verify it has a check valve and if not I'll need a inline check valve that opens at 3 bar.

 This is the knowledge that without, would cause issues later on in this project.
 
 Thank you very much
   Johnny

johnnyw116

#16
Be sure that you use an 3bar fuel pump the D-jetronic injection system works with an lower pressure than the k-jetronic injection system , the k-jetronic fuel pumps are around 6/7 Bar
JohnnyW116

gurrier

Hi all,

I have done some more broad reading with regard to the fuel system and was surprised to come upon the suggestion that the pressure put out by the pump is somewhat irrelevant, only becoming an issue if there should be a blockage in the return side.  Perhaps someone on here would like to comment.

Regards,

Bill
1973 350SE

johnnyw116

#18
They say that with an pump with more pressure it will run but the on the longer term the fuel pressure regulator goes defect and it is also bad for the injectors

https://jetronic.org/en/d-jetronic/fuel-pump
JohnnyW116

McGhee5120

Well the pump I purchased is a Bosh 45699FF its a turbine pump with little to no pulsing, and because it came with two external check valves I must assume there is not a internal valve.  One of these allows for a banjo fitting so I'll try to find one to adapt to the hose. I'll have to research this pump on its output pressure.

johnnyw116

#20
you only need the checkvalve for the banjo fitting to connect the pump to the fuel filter ,and you dont need the other checkvalve , the check valve is just only an one way valve for preventing the backflow of fuel and it also holds the fuel pressure , so now you need the banjo and the bolt for it
JohnnyW116

gurrier

Fuel Line Banjo Bolt 80810600
Fuel Pump to Fuel Filter with 2 Banjo Fittings 1234700675 
MB 001-091-71-01 is the pump with the prepared fittings kit that you will receive if purchased from MB
1973 350SE

Jan S

The pressure damper on your third pic is a cavity, i.e empty space. A thorough clean is sufficient, especially inside. I believe it's fairly corrosion resistant. Let it soak a day or two and use a brush, compressed air, etc. If inside looks really bad this is also a good case to test out a ultrasonic washer.

My understanding is that the pressure damper reduces pulsation on the suction side of the pump, i.e. makes sure the flow to the pump inlet is steady/even/stable?

I renewed the fuel assembly (k-jet) a while back (se pic). The frame, the holder for the tank hose and the pressure damper I cleaned - all the rest is new.

I also installed an extra pre-filter between tank strainer and pump inlet (at the top in pic) to avoid "larger" particles entering the pump. Works fine so far.
1975-mod W116 450 SE with 6.9 engine

McGhee5120

  Update:

  Well, I think I've got all of the fuel system lines, hoses, and tank sending unit ordered. Most of the engine crankcase breather and air pump hoses, and engine cooling system hoses ordered. These will start coming in next week through the middle of August.
  Hopefully I'll be able to start the engine next week and verify what if anything is needed on the injection/ ignition system.
  I've only started researching the vacuum system and looking at the actual vacuum lines, switches, and reservoirs on the car.  The small colored vacuum lines appear to still be flexible and in good condition, all of the small black rubber lines will need replacement.  This is really impressive what all they have done with vacuum, I just hope it all works when I get it running.  I've worked with vacuum in the past but not on anything quite this complex. 
 
 Johnny

McGhee5120

Pushed it outside till the parts start coming in, and took a little better pics outside.