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Fuel Management

Lubrication of MFIP
Author Last Post
Peter,
Gus discusses this in Part 1 of Brian Glusovich's videos that are in the Members Only Technical Archives on this website. The video and audio is not of good quality at the start, but it improves by the time Gus discusses the oil lubrication with Brian using a cut away early 6 cylinder pump. He explains that the upper "lubrication" is really a hydraulic seal with no through flow at the level of the injector plunger elements. It is worth a look (and there are several Parts to follow) before you visit Gus, presuming that you have joined the Group and have access to that part of this website. That way you will have the benefit of some of "the old German"'s knowledge before you meet him. It would be great if someone would learn from him and take over his business before he stops. I don't know how old he is, but he is older than me and can't last forever.
Art
Art,
Thank you. From what I know your explanation makes sense. When I get to meet the old German who owns Pacific Fuel Injection I will share the knowledge.
Peter

Peter

The early 6cil FIP have the same methode as the 6.3 FIP, but the second generation of those FIP have the internal lubrication via the motoroil.

early generation :
PES 6KL 70 A ... ...

second version :
PES 6KL 70 B ... ...

The second generation started at the M130 motor 280 SEL, SL, SE ...

The M100 never recieved a second generation FIP.
Francis,
You are correct. Some of the 6 cylinder pumps are like the 8, some aren't. My apologies. I should have said the 6 cylinder pumps from the same time period as the 6.3. The pumps on the 280SE motors don't have the oil filler or the dip stick. I don't know when this was changed, but from what you are saying about your 250SE, it may have been with the start of the 280SE. Maybe someone else knows.
Art

P.S. Doesn't alter the most common cause of overfilling of the 8 cylinder pump sump being leaking internal seals.
Art, I'm not sure of your statement on the 6 cylinder engines as my W111 250SE has a dipstick and filler tube. Am I missing something?

Francis E. Abate
There is a third possibility. On the 8 cylinder pump, the "bottom" of the pump has its own oil supply as you correctly mention, which is separate from the engine oil system and has its own oil filler with the red cap and its own dipstick at the rear. It splash lubricates the governor and related camshaft components. However, there is a second oil feed to the upper part of the pump which comes from the oil filter housing at engine oil pressure. There is no return line. If the gaskets related to this part of the pump leak with time, engine oil from this pressure line seeps into the lower part of the pump, overfilling the sump of the pump. Only the 8 cylinder pump has this set up. The 6 cylinder pumps do not have a separate sump and are lubricated by the engine oil system.
Art

The FIP from the 6.3 has a separated Oilreservoir with its own dipstick.

there are 2 possibilities :

the FIP was overfilled with motoroil or
the oil contains leaked fuel (you should smell that)
1971 300SEL 6.3 Mfg 2/71. I removed the dipstick (14mm hex) and excess oil flowed out. I thought the oil in the MFI pump was separate from the motor's lubrication system. Is it? How can the oil be overfilled? FYI Pacific Fuel Injection south of San Francisco rebuilds pumps for MB Classics in Irvine.

Peter
Tom,
It is standard engine oil. Because it tends to be forgotten and not replaced too often, I would recommend that you use Mobil 1 or an equivalent synthetic good quality oil. A plastic medical syringe of 30ml capacity or more with a length of plastic hose is one way to empty the MFI sump via the hole left after removing the hex nut based dip stick at the back of the pump. You just about have to climb up over the motor from the front to get to it at the back. Put a fender/mudguard protector or blanket over the motor and climb up over it. You can fill it via the red capped Oel filler at the middle of the pump.
Art
Hi

I have tried to search for the type of oil to use in MFIP, but can not come up With an answer, can someone help out?

Sorry for "bombing" this Group With questions, but I need to learn from you guys ;-)

Tom
Hi Art,

so with 250ml I'm right on the money? [;)]

I'll fill it with 250 then, and see what the dipstick has to say.

Gunter

w109 6.3 #1452 '69
s124 300 TDT '90
Skoda Superb '09
Gunter,
As far as I know, capacity is between 200 and 300ml.
Art
Hi Anthony,

The drain of the V is full of muck, so I'm not going to get the oil out that way.

I'm just a bit worried that I don't get all the contaminated oil out, so I just want to make sure I can insert the "suction hose" deep enough in to the dipstick-opening.

But thanx anyhow!

Gunter

w109 6.3 #1452 '69
s124 300 TDT '90
Skoda Superb '09
I empty the MFIP oil by removing the dipstick, placing a drain tray under the valley drain and blowing gently into the open filler tube with a clean piece of PCV tube that fits snugly into the filler, the old oil flows out of the dipstick tube and down the valley drain, quick and easy[8D]

300SEL
6.3 #2723, my first classic Benz
3.5 #8659, my second.
2 to go...
Hi Ron,

thanx for the info. The tube I am using is quite small, even less than 6mm I think, but I'm having difficulty inserting it deep enough. Is something below the hex-screw thread hampering the tube from getting really deep inside the oil-reservoir of the pump?

Now, if I suck out all the oil that is inside the pump, approx. how much oil will I need to put back in?

Elsewhere, I read that it is better to put a bit less oil in, than too much (regarding the functioning of the governor)

Gunter

w109 6.3 #1452 '69
s124 300 TDT '90
Skoda Superb '09
Hi,you only need to suck it out through the dip stick hole ( the hex bolt) . you wont reach the oil through the filler because the governor links are in the way. A 6mm tube should be OK. It's not a matter of the oil getting dirty with fuel but the oil level getting too high and affecting the governors action. When this happens it means that the injection pump elements oil seal is leaking and excess oil is entering the pump and flooding into the governor. The oil is just to keep the governor lubricated and working smoothly so it's not vitally important that it is kept changed. It all means that frequent oil changes of the engines oil is necessary to keep the injection pump in good order. [:)][:)]

quote:
12-14-2004, 11:49 PM #8
Tom Hanson
MBCA Member

What the heck, try to stuff a MB 6.9 liter V8 in it. What a machine that would be..
__________________
Tom Hanson
Orange County Section
Hi all,

I've been enjoying #1452 quite a bit. A few weeks ago, she performed admirably on the family-trip to the Antwerp Classic Car Event.

Now, to the point.

The weekend after the Antwerp Event, I got in a special big syringe and small hose that I ordered on the net, and decided to change the oil in the MFIP.

The contents of the pump smelled quite hard of fuel. The oil was still "greasy" but it was quite thin.

Now, to be on the safe side, I'm going to change it again this week.

The hose that I'm inserting in the pump is long and very thin. How can I get at the bottom of the pump the best? Through the hex-screw? It seems that I don't really get to the bottom of the pump. I can insert it about 2 or maybe 3 cm through the small opening under the hex-screw, but I feel something is blocking it, and I think I sould be able to get it in deeper to get more oil out. Or can I get the most oil out through the filler-cap?

Thanx for any info!

Gunter

w109 6.3 #1452 '69
s124 300 TDT '90
Skoda Superb '09
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