I have a 1978 Mercedes 240d with a om616. Last summer I ran a 50/50 mix of diesel and filtrated vegetable oil (down to 2 micron) and then parked the car and it sat for more than 6 months. Recently I tried starting it but to no avail. I have narrowed the problem down to the injection pump. I took off all 4 of the pipe connectors and soaked them in carburetor cleaner for a couple of days and it got rid of all the junk. I reinstalled all of them and got port 1,2,3 to squirt diesel. However, port 4( the far most to the right) still will not squirt fuel. I suspect that the vegetable oil has gelled up from siting so long and is causing something to stick. I went down to my local diesel injection shop and they said that it would cost around $1600 to rebuild the pump. I can buy a new 240d for that price. Anyways, if anyone has any experience with this or has any idea what I can use to clean out the "junk" feel free to chime in.

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I would try running some lubro-moly diesel cleaner through it, you might be able to get it to idle on 3 until #4 frees up. The lubromoly should be run from a small bottle with both the supply & return lines going to it.

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$60 OM617 Blank Exhaust Flanges
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I have used Lubro-moly before with good results. I think I have a couple cans in my garage. I usually run it twice a year to clean the injectors. Goes in clear comes out black through the return. I haven't tried to start it on 3 cylinders yet. But, will give it a try. Thanks for the advice.

You can only do this with the MW Fuel Injection Pump like the one in the picture. I hope no one try this with an M type Fuel Injection Pump; the one that needs the special splined Socket to remove the Delivery Valve Holders.

On your MW Fuel Injection Pump remove the Delivery Valve Holder I believe that is the part you car calling the Pipes as I have seen that word used in the Manual. Do not touch the Nuts on each side of the Pipes.

Remover the Delivery Valve Spring and the 2 piece Delivery Valve. You should be able to look inside and in the center is the Element Plunger.
Have someone rotate the Engine by hand and look inside and see if the Plunger is going up and down.

If it is not moving it is likely that the Plunger is stuck in the upward position.

If the above is the case; I have done this before but it requires that you be extremely careful. You take a 4-6 Inch section of 1/8" OD BRASS Brazing Rod and and get something light weight like a big Spoon.
You round off one end of the Brass Rod. You insert that down the center onto the top of the Plunger and you tap lightly.

If it does not move rotate the Engine about 1/2 a turn and try tapping again. You should reach a position where you can tap the plunger down but it will not move far.

You need to rotate the Engine to rotate the Camshaft in the Fuel Injection Pump so you are not beating on the Plunger when it is being held up by the Fuel Injection Pump Camshaft. That is why you need to tap gently so you do not damage anything.


If the Plunger goes down lube it with WD-40 or Diesel Fuel. If you manage to free the Plunger up you need to bring the Plunger up to the top and inspect it for Brass particles and you need to air gun the particles out.


If the Plunger is not stuck and is moving up and down OK that means the Fuel Feed Hole in the side if the Element is plugged. I guess you will need to find some chemical that can unplug that because if you remove the Element you mess up the Fuel Adjustment on the element.

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84 300D, 82 Volvo 244Gl Diesel

I cannot answer why 1 port is not squirting diesel. I am pretty sure that 50/50 mix will not gunk up IP in 6 month, not even with 100% WVO. Have you tried to start with 3 cyl?

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

In the Left Pic the 2 piece Delivery Valve Assembly is removed and you can see the top of the Element Plunger. That is were the 1/8" Brass Punch is going to go and you want the end of the punc to be rounded so it centers in that center hole on the Plunger and that way the punch will not move around.

You don't want to pull one of these out but that is the Fuel Injection Pump Element outer Barrel and the arrow points to the Fuel Feed Hole that might be plugged.

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84 300D, 82 Volvo 244Gl Diesel

Some wvo by products have turned into a glue type substance when the engine sat. It may take a few days of sitting with some laquer thinner to loosen up all the gunk.

Leave the injector lines off. Pump the laquer thinner in with your finger pump and let is sit. Chemical action is slow to non existant at low temperatures so get the injection pump warmed up to room type temperature.

Turn the engine over and watch for some squirting from all the ports. When it occurs then pump clean diesel into the injection pump with the relief valve removed so the junk and thinner can leave the pump better. You may get globs of stuff.

If the fouth port is still not producing give it a little tap then. Rotate the engine. If still not working let the soaking continue for a few more days. The laquer thinner should dissolve all the junk.

The small piston in the bore is a really precision fit so it takes a solvent some time to get into the thin space and at the sticky stuff. Laquer thinner is a good solvent for animal fats and a lot of other things but not aggresive towards metals.

You do not want to leave that stuff in the injection pump anyways. The diesel fuel is not really a solvent for it. But a good soaking flush can be cheap and effective.

The stuff in a can is too weak in concentration to get the congealed fats dissolved etc for sure. I am not even sure if it is designed to tackle what you probably have. The soaking period is the secret with the laquer thinner as it breaks down the undesirable stuff. What you eventually do is pump all the junk and laquer thinner combined out through the relief valve with fresh diesel rather than feed all the trash through your injectors. Should work out okay. Now if the wvo had water in it I am not so sure as there may be some damage. At present I go with the glue probability though. This soaking is easy and cheap to do.

Personally I would remove the relief valve as it makes pumping in the solvent and pumping it and the junk out easier. If you do give it a soak in the laquer thinner as well. Also remember that the laquer thinner is seriously flammable. Probably about ten dollars a quart.

Its probably not the injection pump.....the injection pump is most likeyl not getting enough fuel pressure to pop the valves.....this stuff turns to a sticky tar....as it breaks down...specially if was bio or diesel that contained 5% bio...

Try replace the fuel filters and attempt to start the car off a gal jug of PETRO diesel and see what happens....if it fires....drop and clean the tank...

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If it is a stuck plunger: would it work to put hydraulic pressure against the top of the plunger to push it down onto the cam and then hold it there while the cam is rotated enough to free it ? If so, what would the best fluid be ? ATF, MMO, Seafoam, diesel, B100

The advantage of this method (if it is viable and works) would be that you do not have to open up the pump and risk having things go horribly wrong.

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Greg
2012 S350 BlueTEC 4Matic
2007 ML 320 CDI
2007 Leisure Travel Serenity
2006 Sprinter 432k
2005 E320 CDI
1998 SLK230 (teal)
1998 SLK230 (silver)
1996 E300D 99k, 30k on WVO
Previous:
1983 240D, on WVO
1982 300D, on WVO
1983 300CD, on WVO
1986 300SDL 237k, 25k on WVO (Deerslayer)
1991 350SDL 249k, 56k on WVO - Retired to a car spa in Phoenix
1983 380 SEC w/603 diesel, 8k on WVO
1996 E300D 351k, 177k on WVO

I just like to see any car that has used wvo and sat around for a period of time subject to a good system soak and cleaning. When pumping the injection pump full of a solvent you get any residual stuff in the lift pump soaked as well. By products of wvo seem to change consistancy with time. Becoming a glue like substance or extremely sticky.

I do not think the suspect stuck element piston is that big of a deal. I did suggest soaking the relief valve as well when off as it may be held open by the stuff . The lift pump is covered my way at the same time.. Easy for a valve to be stuck in there as well. Or not sealing as it should with waste buildup. Removing the secondary filter dumping it and filing it with the laquer thinner gets the thinner into the injection pump quicker as well.

I right or wrong approach things so I will not have a road stoppage issue or reduce the chances of one as much as possible. I learnt long ago that any stoppage on the road you cannot quickly rectify will cost you money usually. Overall you will normally lose a days time with the event. In fact they can be a real inconvienience if well away from home.

Thanks for the great advice, but I have a few things I want to clarify.
I have attached a picture from the Mercedes manual. When you say to remove the delivery valve holder, spring, and 2 piece valve are you referring to the parts that are in the image. If so how do you remove (6) or pressure valve carrier as they call it. Is it a press fit?

From what I can remember you can rotate the engine by the powersteering pulley instead of the crank if the belt is tight enough. Correct?

Someone else mentioned that it is best to soak it in paint thinner, so I might try to do this to free things up a bit before taping it to make things easier.

Also, is the method you described above possible with the injection pump off the vehicle? Would it be easier to take it off or do it with it still on the vehicle?

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Tried to start with 3 cylinders and no go. Just cranks for a long time.

The picture on the right is what I don't want to remove. Its what you referred to as the two nuts on the side of the pipe connection. Good thing I read this because I as thinking about removing it to see if it was gummed up. But, I saw the nuts were painted with a paint pen and had my doubts.

I have seen wvo gel and its nasty stuff, especially when its cold out and it gets some water in it. Anyways, I am going to try this method but unfortunately it is in the upper 30's here and as you said chemical action is nonexistence. I am either going to wait until it gets warmer or take the pump off. Also, I have a can of acetone, kerosene, and xylol in my garage which do you think will work best, or should i stick to paint thinner? I will let it sit and soak in for a week or so as I am in no hurry and then pump it out the relieve valve. I'm wondering if the paint thinner or solvent will have any affect to the diesel or any reaction. Thank you for the advice.

First thing I did was change the fuel filters, both main and pre-filter. The diesel is coming in clean through the pre-filter with no gunk. So I hope the lines are clear. I believe the pump is getting enough fuel pressure. After taking off the pipe connections, soaking them and reinstalling I primed the fuel pump with the hand pump and got a stream of diesel to the face( not fun) from port 1,2,3. The car is also parked on a slight decline towards the front of the vehicle, so the diesel is getting there even if by gravity.