Looks like rebuilding the lift pump did the trick. I took the car out today and it ran great. Thanks Tango, for the kit and everyone else for the good advice.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

OK, fast forward three months, the fakakta pump is still giving me issues, dammit.
Every time if the car sits a day or two, the plunger on the inlet side gets stuck. I have to pull the primary filter and stick a long small bladed screw driver in the pump's inlet to unstick it. I've tried adding MMO to the tank hoping it would help. NOPE! It's as if something is gumming it up but the fuel is clean and has no residue or clouding. I've taken it apart and everything is clean.
I am at wits end and I am tired of my hands perpetually stinking like diesel fuel and my wife *****ing at me about that I always stink like friggen diesel fuel.
It stupid little things that this that make me hate this car.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

After you are done with your Car for the day loosen your Fuel Fill Cap enough to relieve any Vacuum and leave the Cap loose over night. In the morning before you tighten the Fuel Fill Cap if the Car will Start normal. If it does you have something causing a Vacuum in your Fuel tank like a restricted Fuel Tank Vent.

For the pump itself.
Is there any chance that the small diameter shaft on the Valve is sticking in the Bore it rides in?
Remove Cap that is in the Bottom of the Lift Pump that holds the Valve and spring. Remove the Valve and spring and take the Valve and stick it back into the bore in the Lower Cap. gently move it up and down and rotate it a little and see if it is sticking any where.
If it seems to be sticking there may be a metal burr in the bore or on the edge of the bore. If there is remove it.
If the Valve itself is too tight take some fine Wet/Dry sand paper and sand it down some to reduce the Diameter of the shaft and see if that will free it up.

Compare the New Spring with the Old Spring and see if they are the same length. Use which ever has the longer length.

If you still have the old Valves you could compare the old to new Valve and see if there is any physical differences in them.

Look to see if the Head of the Old Valve is smaller in diameter than the new Valve.

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84 300D, 82 Volvo 244Gl Diesel

I'm pretty sure there are no differences in the valves themselves. They fit together fine when I reassembled it the last time but I can easily pull it apart again to see. I don't have many of the original parts left. Most went into the trash long ago. I did find one of the valves as I was sweeping the garage floor a few days ago. The original springs disappeared when I dropped them the first time I took the pump apart.
I might just look for another pump in the wrecking yard if another 300D shows up. The spare IP I have doesn't have the lift pump. That lift pump is the one on my car now. I got rid of all old lift pumps when I sold off most of my spare engine parts a few years ago.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

With out seeing it myself I cannot comment any more.

I suppose a small air leak in Fuel Inlet could also allow the Fuel to leak back to the Tank.
You might try clamping the Fuel Inlet Hose off with a C-clamp or Vice Grips at night and removing the Clamp in the morning to see if that makes any difference.

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84 300D, 82 Volvo 244Gl Diesel

It sounds like you've been through it all a million times but just to be sure did you strip the pump down as far as this?

Refreshing the fuel pump on an OM617 (European spec – non turbo)

If this doesn't help, may be it is time for you to post some photos - and not just of the fuel pump... are you sure there isn't a leak elsewhere?

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Your Fuel Supply/Lift Pump is different; it has the Disc type Valves in it.

If he has a MW Fuel Injection Pump Like mine (I have the same year and model as he does) it has sort of T shaped Valves with seperate springs.

Attached Thumbnails

 

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84 300D, 82 Volvo 244Gl Diesel

I think at this point I would try another pump if you have one from a parts car.

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

Precisely the ones I have.
I had the pump completely pulled apart when I rebuilt it the first time. I cleaned all the parts that were reused in carb dip to ensure everything was spotless. I didn't check anything with a micrometer because I didn't have any reference specs. Nothing appeared scored or damaged and everything fit without any play.
The only thing I haven't checked thoroughly are leaks. Nothing leaks at the pump or immediate area nor are there any kinks in the lines. There are no restrictions once the valve at the inlet is freed. Fuel flows well when I pump the primer. The car runs fine when the valve isn't stuck and will run w/o an issue the whole day. Oddly it will still run when the valve is stuck but it will starve for fuel to the point stalling after running at higher RPMS for about a 1/10 of a mile. I cannot pump fuel with the primer if the inlet valve is stuck. The filters were changed to rule out any clogging.
I have not checked the fuel cap yet but I don't feel it is an issue. If it was I would have drive-ability issues regardless of the inlet valve being stuck or not.
I'm thinking of just bypassing the lift pump an use an electric pump instead. I have a nice little Facet pump from WVO system that I had used in a Dodge truck I once had.
Stevo, I no longer have any parts from a parts car. All I have is an extra IP, a starter, a couple of alternators and some odds and ends that all fit in an old beer box.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

Negative pressure in the fuel tank would tend to close the suction valve, not hold it open. Seems to me you must have a mechanical problem of some sort with the suction valve.

Yes, it's the suction valve that gets stuck but it only gets stuck after it sits overnight or longer. It doesn't stick when the engine is running. I can tell when it's stuck when I cannot manually use the primer.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

I don't know if the design of the Valves and seating area well enough to hold more vacuum than is normal.

In one of the Lift Pump threads someone put something inside and manager to lap the valve seating area inside of the Pump.

Perhaps there is some issue with the valve seating ares in the OPs Lift Pump.

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84 300D, 82 Volvo 244Gl Diesel

It's possible there could be an issue with the seating area but I have no way to tell unless I had another pump body to compare. It appeared OK upon the initial disassembly and cleaning. The valves themselves are of some sort of plastic material and would be prone to wear opposed to the metal pump body.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

If it is rusted or pitted that would be enough.

I am posting the below photos just in case the Valve is not oriented right. It is possible to get the valve in upside down.
If you have yours in righ OK; maybe it will help someone else.

I looked for my spare Lift Pump but could not find it so I had to draw the bottom cap.

The first pic is the Bottom Plug where the Valve is located.

Next Pic is how the parts are arranged top to bottom with the Plug being on the bottom.

I believe it is possible to get the Valve upside down With the Cross on the T on top of the Spring and the shaft of the valve would be sticking uwards through the Fuel Inlet hole.

Attached Thumbnails

   

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84 300D, 82 Volvo 244Gl Diesel

I had the same situation with my discharge valve. The original valves/springs were gummed up. Fortunately, cleaning the pump and installing the repair kit fixed my problem.

Installing that valve upside down would be quite a feat. And if it was (in theory) so installed, the pump would never work.