OM615 Injection Pump Information
 

Hello all,

I recently purchased a 1973 220D. The car does not currently run. It will crank, but has a lot of blowby. From what I can figure, the car hasn't been on the road since at least 2000 so it will need some work. Someone has tried working on it previously and got just far enough to mess me up.

Anyway, I have a few different questions.
A: how do I properly change the oil in the injection pump?
B: how many fuel lines go to the pump?

There is one line going from the fuel bowl to the pump, but it looks like there are at least two other fuel lines. From what it looks like, there is a spot for a rubber line and a line to thread on right next to the priming plunger. Where are those two lines supposed to lead?

Thanks in advance for any help, I know basically nothing about these cars other than what some quick google searches have turned up!

I don't think the oil in the injection pump can be drained to change it, I think the normal maintenance is to just add oil until it starts to run out, then put the plug in.

I'm not sure on the "MW" pump but the "M" gets it's oil thru the front gear case so engine oil just handles it.

Dan

Thanks guys, what about the fuel lines? Obviously there will be at least one supply line and one return line, just not sure what the third possible line is for.

Don't forget folks that OP has a pneumatic (vacuum) governed IP on his older engine and these particular ones have no external engine oil feed (or internal!) It is necessary to change as it gets diluted with diesel over time because the seals aren't perfect.

There should be a drain plug somewhere around the bottom....and refill via the big red cap with engine oil

As for this fuel line.... there are two return lines that join to one, you would have the older setup which I'm not familiar with, pics would help :)

Just got out of work, 2am here in Michigan, I'll try to grab some pics later this morning, thanks Scott.

The 2 lines next to the primer pump are actually inlet and outlet for the lift pump, they aren't connected to the ip. It goes like this:
fuel tank -> prefilter -> lift pump inlet -> lift pump outlet -> big fuel filter -> ip inlet -> ip outlet with pressure relief valve banjo bolt -> air vent bolt on the big filter housing(injector overflow merges here) -> return line to tank.

Not the best, but maybe these pics will help.

That gives me a little better idea, thanks guys!

There is instructions in the Repair links on changing the Oil. On most of them you need to suck it out with a tube attached to something like a Turkey Baster or one of those syringes they use to inject flavors into meat (often had at the 99 cent stores here in S. CA).

When you fill it on the Engine Block side of the Fuel Injection Pump is usually a Banjo Bolt that holds a U bent tube sometimes called a Goose Neck. The excess any over filled oil will come out of the tube.

Also in the Repair Links look up how to test the Pneumatic Governor for vacuum leaks.
The Repair Links:
http://www.peachparts.com/shopforum/diy-links-parts-category/

NZScott, I realize this is a late response on this thread, but I have one of the IP's where Oil has to be manually added. I've had a lot of loud clatter when first starting up my 72 220D and recently drained the oil from the IP (finding it was pretty much just diesel) and refilled with oil. Wow, suddenly my car sounded like new.... after a couple quick drives it is clattering again. I'm assuming at this point (as I'm no IP expert) there are some worn out seals in the IP which are letting the oil and diesel just mix right together. Does this sound logical? Any idea on repair options?

That's odd, sure the clattering isn't ignition related? Guess you could hear some clatter from the IP. Only IPs that I know of that make noticeable clattering are ancient CAV ones on Listers etc...

Well recently I've done a valve adjustment, upgraded the glow plugs and done a diesel purge all in the hopes of getting rid of the clatter. When it still was an obvious problem I started searching on every topic I could find around engine clatter in these old diesels.

Pretty much everything pointed to the injection process so I started thinking about everything I could do related to the injection process. I did another purge but that only made a very minor change. Then I thought... I haven't ever really invested time in the injector pump yet. So I looked around for all the information I could find on the pumps and found several threads about replacing the oil and how diesel would mix with the oil over time. When I drained out my old "oil" it was pretty much 100% diesel. It was as soon as I refilled with the correct oil and started the engine that everything just purred.

So I'm wondering what if anything there is internal that would allow such rapid mixing of the oil and diesel. It seems like if I could just keep pumping in more oil that would keep it running quiet, but then I'd be burning more oil too (which seems to have picked up recently).

As I understand it there are two routes fuel could follow into the lower portion/sump of the IP:

- Leak past the IP elements; or
- Leak past the o-ring on the push rod that operates the lift pump.

The o-ring in the lift pump is a relatively easy fix (remove the lift pump and replace that o-ring, or rebuild it entirely). If the elements leak excessively then you'd be looking at having the IP rebuilt with new elements ($$). If the elements are worn out I'd suspect you'd have other issues caused by the lower pressure getting to the injectors from the IP (poor engine performance).

Do you get so much fuel in the IP that it drips out of the curved vent tube on the engine side of the IP? I had that on the '73 a few years ago. Rebuilding the lift pump cured it.

I'm not sure how much diesel is coming out the vent tube. I'll pay close attention to that over the next couple drives.
Did you rebuild the lift pump yourself or go to a shop? I've not seen anyone selling o-rings or other IP parts except the o-ring and washer that are where each hard line attaches.... nothign for the lift pump.