I opened my #5 delivery valve to see wether there is any crud in there.

I didn't see the copper washer that's supposed to be under the valve (84SD). Also, is there an easy way to stop the fuel from coming out of the IP when the valve is out. I'd like a better look at where the washer is supposed to sit.

Perhaps my understanding is wrong and the washer isn't at the bottom???

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

Your copper seal is likely in there, stuck solid to the bottom. A dental pick or a paper clip with just the last millimeter bent over 90deg works to pull them out. It can still be a patient job. DO NOT pry out with a screwdriver or anything else that could potentially scratch the sealing surface.

I used a length of thin hose taped to the nozzle of my shop vac to pull all the fuel and debris out. Flammable fluids, lots of air, running electric motor, probably not a good idea, but I did it and lived to tell the tale. At your own risk.

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617 swapped Toyota Pickup, 22-24 MPG, 50k miles on swap

All of the vids show a dry chamber so I was surprised that fuel seemed to keep flowing. I have a pump that may work.

Here's the pdf from the FSM.

Attached Files

07_1-210.pdf (316.9 KB, 114 views)

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

If you rotate the engine a bit, the pump will also rotate and close off the feed hole into that chamber and stop the flow of fuel.

The copper washer is clearly shown in the diagrams on the third page of your attached document.

The purpose of the washer is to make a tight seal between the delivery valve holder and the top of the part inside the injection pump that feed the fuel to the delivery valve. This copper washer is a one-time-use seal and should be replaced with new each time you open up the delivery valve. In an emergency, you could try re-softening the old washer by heating with a propane torch until it is glowing orange, let cool and clean off any carbon, and then install.

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Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

What goes wrong with the delivery valve to be a source of rough idle that some have reported? The internal moving parts are hard steel and not prone to wear. The spring could deteriorate but what else.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

The delivery valve itself wears out and the face develops pits and ridges, preventing a complete seal. The copper washer is the seal between the DV and the holder. If it is missing or leaking, you will have fuel pressure loss.

Focus on injectors first. Only after you've ruled out compression AND injector problems should you focus on the DV.

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Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

No, check the FSM diagram again. The copper washer is at the bottom, last thing that can be removed before you are into the pump internals. The holder is labeled as the pipe connection in the diagram, unless maybe you are talking about something else?

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

Revised statement: The copper washer is the seal between the DV and the pumping element. Same idea, if it leaks, you have pressure loss. If it's missing, the DV will never seal against the pumping element.

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Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Seriously not a good idea. Lethal with gasoline, highly risky with atomized diesel fuel. These shop vacs have series motors with a commutator and brushes. Major sparky sparky. And they rely on the exhaust air to cool the motor.

If you have a TopSider oil extractor, those can develop some pretty good suction.
Rig a little inline 1/4” valve (check the drip irrigation aisle at the home center) so you can build up some vacuum in the chamber and then let it rip when you have the hose end in place. (Or just put your thumb on the end of the hose and pump it several times.) A whole lot safer than an electric vacuum cleaner.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech