I've been working on my 72 220D injection pump and have freed up the plungers except for the farthest forward plunger. It moves up and down in the barrel but not as deep as the other ones. Questions,

-Does the outer barrel move along with the plunger? See below.
-Can the outer barrel be removed from the pump from above? Does it just drop into the pump?
-I have rotated the pump via rotating the engine and the plungers move up and down. The outer barrels move up and down slightly.
-Is there something that could of dislodged inside the pump?

The forward barrel sits lower in its hole than the other three. Maybe 1/16 inch lower.

Thanks, Sam

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Yes. Each cylinder barrel has a small clip from the rack that connects to the cylinder inside the pump. As the rack moves each cylinder rises or lowers from the racks action I believe. Usually there is a plate on the pump that can be removed to see these connections that are adjustable I think.

The problem if needing adjustment from being bent is a serious calabration thing. If one has been displaced though and the clip was not bent it may be restored by insertion of the clip into the cylinder slot.

I have little to zilch knowledge of these pumps though you should remember . If the pistons where stuck with quite an amount of rust versus just gummed up the cylinders may be shot as well. Fit between the cylinder and it's piston is a major tolerance issue from a manufacturing perspective. Conceivably even hand lapped final fits back when that pump was manufactured.

I know zilch about these also but just this week I carried one to a shop if you need parts it could possibly still be available. It belonged to a friend who saved good parts from his 220D (including pistons, cam, etc) He gave them to me when he moved away recently. if interested in the pump PM me. I don't check into the forum regularly but Emails get forwarded to me, so if you have some questions I can ask the local hop where they USED to rebuild these, sadly that is no longer the case. Reid

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'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!

When the Pump is assembled the Barrel/The outer Steel Part remains stationary and has a groove that has to be lined up with a Pin that you cannt see looking downe inside.

The Centreal Plunger/Cylinder moves up and down and the stroke on al of them is supposed to be the same.

If the Return Spring is broken that can keep the Plunger from going down far enough as can Rust or other Gunk that has a stronger hold on the Plunger than the Spring can deal with.

If you remove the Side Covery you should be able to see the Springs.

It could also be an optical illusion. If the #1 barrel has moved up and stayed up it could appear that the Plunger is not going down far enouh.

To check that bring the Plunger down to the bottom of the Sroke and measure the distance from the top if the Fuel Injection Pump Housing to the top of the Plunger. Do the same with the others you think are OK.
If they are actually all the same then the Barrel has moved upwards.

You can measure the distance from the top of the Barrel to the Top of the Fuel Injection Pump in the same manner to see if a Barrel has really move up.

What ever you do be sure that the Barrel Alignment Slot is lined up with the Pin in the Fuel Injection Pump Housing before you torque it down.

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84 300D, 82 Volvo 244Gl Diesel

The Outer Barrel can be removed but it has to stay with the same Plunger because they are a mated set.

In My previous Post I showed a pic of the Barrel and the Alinement Slot that when you re-insert the Barrel must belined up with a protruding pin in the Housing.

The Barrel may or may not be hard to get back in. It is going to depend on how delicate your touch is and if you dipped it in Diesel Fuel. You need to squirt or pour some Diesel Fuel on the Plunger.

If you try to use force on the Barrel to get it over the Plunger it can get stuck.
You need to get it over the Plunger and gentely and slowly twist back and forth. What you would like to happen is for the weight of the Barrel to allow it to slide down the Plunger.

Any tiny partical of dirt will bind up the Plunger and Barrel as will no Diesel Fuel on it. Motor Oil is too thick to use. Something like 3 and one, Gun Oil or Sewing Machine Oil may be thin enough to work.

If you do that try to leave the Plunger inside. On the older Pumps the Plunger can go in 2 different ways but will only work one way.

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84 300D, 82 Volvo 244Gl Diesel

The 4 barrels are at the same height now bit the forward plunger is still not dropping low enough to reach the fuel feed ports in the barrel. I've tapped on this plunger several times after rotating the engine/pump. No luck getting this one to move. The other three plungers seem to be dropping down low enough to get fuel but I do pump any fuel to the injectors.

Is it possible a bad diaphragm or vacuum pump could cause a no-start condition?

Could the rack/control rod be stuck in the no fuel position where the plungers would be rotated to not deliver fuel to the injectors?

No Vacuum causes the Governor to give more Fuel. That means if the Govern Diaphragm had a hole in it you would get more Fuel.

One of the things that happens to the Govern Diaphragm is it gets stiff. A stiff Diaphragm might reduce the Fuel.

If the Pump has not been used for a long time the Rack can indeed stick. Infact If one Plunger sticks and will not rotated it will also hold the Rack in that position.

Did you remove the Side Cover to see if any Springs were Broken. Removing the Side Cover will not harm anything.

If the Plunger at some Point gets stuck in the Barrel you could pull them both out and hopefully the Plunger will stay in the Barrel becuse you need to note which way the Bottom of the Plunger Faces.

The below info is is about Bosch Fuel Injection Pumps I worked on 1975-1980. That would mean that they were actually older Pumps that those years.
There is to sides to the Bottom of the Plunger. One side will have like a Chisel Mark on it and the other side will not. Other than that both sides are the same.
The Chisel Mark has to go back in facing the Same direaction as it came out. It is possible to get the Plunber 180 degress off becaus the Plunger will fit into the Sleeve either way.

Now that I think of it the Plunger is goes up and down in a slot in the Sleeve. If that area of the Sleeve is rusted it can also keep the Plunger from moving up and down correctly.
You might be able to tell of the side Cover is removed (this is the Cover Behind the Fuel Supply/Lift Pump).

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84 300D, 82 Volvo 244Gl Diesel

Will raw fuel spill out of the pump if I remove the side cover? Does the lift pump need to be removed in order to remove the side cover?

While what is in the Cover is actually exposed to the Lube you put into the Pump if the upper part of the Pump has Fuel and you pull the Barrel out Raw Fuel will come out.

If you are worried about the Raw Fuel coming fromt the Fuel Tank take a Vice Grips or Cannel Locks and clamp off the Rubber Hose between the Fuel thank and the Lift Pump.

The cover should come off without removing the Lift Pump.

In any event put an Oil Drain Pan or something under the Engine to catch any fluid leaks.

You are on your own after this.
Take the Fuel Injection Pump to a Fuel Injection Shop or buy a used one on Ebay and hope that it works OK.

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84 300D, 82 Volvo 244Gl Diesel

PM me if you need a pump. I wouldn't mind getting it tested, gives me a chance to bug the mercedes guru at the injection shop

I am dealing with the same issue.
I have also started a thread over here:
1971 240D Newly aquired. Injection pump not building pressure. Car sat for years. - Mercedes-Benz Forum

I just removed the pump today. I can take some pictures of it.
Let me know if you succeed in removing the big barrel and fuel element.

The (Fuel) Element is the Plunger and the Barrel assemly and they are mated Parts that cannot be mixed with the other Plunger and Barrels.

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84 300D, 82 Volvo 244Gl Diesel

GOT THE PUMP FREED UP!

I am going to post some details later as I don't have time right now.
And who knows - I might have caused damage as I had to tap on the elements.
In the mean time - SOAK IN TRANSMISSION OIL.
Fill everything, the inside where the camshaft is, the side where the return springs and the control rod(rack) are and also undo all 4 19mm nuts, take out the springs, the plunger and the barrel and fill transmission oil over the element and inner barrel - this thing (http://www.superturbodiesel.com/std/attachment.php?aid=5889). Let soak for as long as possible.

more details later.

Good info. Great that you freed her up. On mine, I removed the side cover and I cannot move the rack back and forth by hand, I don't have the governor/diaphragm portion on the pump removed and the pump is still attached to the engine. When I just grab the rod through the window in the side and try to move it moved about 1/32" and that's about it.

Should the rack move back and forth freely?

thanks

You should be able to move the Rack and you should also feel the spring Tension on it.

Rember if one or more of the Plungers is frozen/stuck in the Barrel the Rack is not going to move.

Also don't touch the little Blocks with screws on the Rack. Those adjust the Fuel Setting on each Element. Moving them changes the amount of Fuel Output that was set on a Test Stand.

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84 300D, 82 Volvo 244Gl Diesel