This might be a good idea. I probably should have done it when I bought the car. Should I just try to rev the engine like I did before during this procedure? I guess if the problem is fuel contamination, it will run better when connected to the bottle.

When you say #1 failure, do you mean within the IP? I did get fuel there eventually, but it took longer than the others for sure. I'll do a search on that for evening reading material (it beats Sunday night TV).

While a diesel purge isn't a bad idea, he's telling you to use the remote "tank" like you would with a diesel purge, just with diesel now.

I really think you should try this first before doing anything else. Grab a 2ltr soda bottle, or something of equivalent size, and put in some fresh diesel. Cut two holes in it, one for supply and one for return, and run fuel line in to it and hook it up to your car. Prime and attempt to start it like you would normally.

Sitting for 6 weeks is plenty of time for junk to build up and cause issues.

OK, that makes sense. I'll follow dieselgiant's instructions, but substitute normal fresh diesel in the bottle.

Its great to see you making progress !!

Fresh diesel is always a help.

For a bottle, I have used an orange juice container, they are clear so you can see the diesel in it. The opening is big enough to put the 2 flexible hoses (cigar & supply to primary filter) in.

An extra claim to fame you now have is you got BC & I to agree on something ! ;) Keep the throttle to the floor !!

If you drain the tank & find black gunk in the strainer, it would be fair to say the problem is found.
The tank vent is probably blocked, they always get that way. Until you have it sorted, leave the fill cap off.
A good nights sleep always diminishes mechanical problems with a car !!

no, I mean cylinder #1 on the engine is known to fail on the 240's due to low fuel pressure to the IP...

In a situation such as this, where algae fuel contamination is suspected, would it help to try to use a siphon hose (e.g. a cheapie shaker siphon) to pull a fuel sample from the bottom of the tank? Or is the algae too viscous or some such to be picked up properly?

Is this siphon method an acceptable approach to draining the tank, if need be? What is the canonical method?

I've been running Racor biocide and Stanadyne Performance Formula in my 240, and have been wondering whether the demulsification has over time created a pool of water in the tank (with any algae suppressed by Racor). Haven't yet tried to poke a siphon in there to try to find out.

Take out the fuel sender, easier then siphoning or draining the tank. if you see black on the aluminum fuel sender, you have algae.

I set up a bottle with fresh diesel in it, changed both filters (filled spin on with fresh diesel), primed ... no start ... even with pedal down, I can't even get a little try out of it. There is some reason I can't get air out of the system, and I really don't understand it. Maybe my primer pump is broken (already). I continually get air bubbles in the clear fuel hose between the spin on filter and IP. No matter how much I pump, more bubbles appear, and they don't always come out of the loosened bolt on the spin-on filter (plenty of diesel does though ... there is just diesel everywhere in my garage).
I used the same set-up as the dieselgiant tutorial, only with diesel instead of DieselPurge. Fuel does drip out of the return hose, when I prime or when I crank. But it's not always coming out of the fuel lines on the injectors.
Taking a break ... the diesel smell is making me sick.:rolleyes:

Oh Dear !!
Looks like you have a leak of air into the fuel.
Is the little primary filter part of your set up? They can have leaks around the hose fittings.
The most likely place air will be getting in is on the vacuum side of the primer pump. Is the hose good?
Are you getting a good stream of fuel out the return line when you pump the primer?

I had an annoying air leak on my diesel jeep. It has a similar fuel system. I ended up using a can of spray glue & making a mess spraying every connection 1 at a time & testing until I found the air leak.
Probably if I was as frustrated as you must be by now, I would put a small electric fuel pump in the line from the bottle & set it going for a while circulating fuel under pressure until every bit of air was gone. But thats just me!
I prime my 617 by attaching an air hose to the return line to the tank & lightly pressurizing the tank. It has the old style primer pump & it leaks & so destroys engine mounts & I have trouble getting it to seal after priming. You can hear the air exiting the tank vent. The return line out of the filter housing I have going to a bottle. When there are no more bubbles of air, I quickly reconnect the return line to how it should be. It takes some skill as if you are not quick, the diesel under pressure in the tank comes back up the return line & gives you a face full of diesel. Dont ask how I know !! :D
What happened with the WD40?

Sorry for asking so many questions, its just my way of making suggestions (the answers).

Try this:

With all seals tight, crack open the banjo bolt on the fuel pressure relief valve on the IP (backside, facing the block near the temp sender), then use the primer pump to get the air out of the filter and IP. Tighten the banjo bolt. Make sure all 4 glow plugs are good and getting voltage. Crack one injector nut and crank till it starts, tighten the injector nut and feather the throttle and watch the clear return (cigar hose replacement) line till the bubbles clear.

If you can't get it to start after all of the above or can't get the bubbles to clear if it starts, you need to get the Mityvac out and find where it is leaking air in.

I doublechecked the fitting around the primary filter (which is new) and tightened the hose clamps a little bit. The supply hose should be good, I just bought it. I made sure it is fully submerged in the bottle of diesel. When I pump the primer I can see the hose pulse (if that's the right word). I can't see any air in the primary filter (not even the normal bubble). I tried:
-cracking the bolt that goes from the secondary filter housing to the IP and pumping. Diesel (no bubbles) comes out.
-cracking the banjo bolt on the side of the IP near the temp sender and pumping. Diesel comes out without bubbles. I pumped a bit of diesel through then tightened it.
-adding the clear tube where the cigar hose was on the last injector. I can see diesel begin to rise in it when I pump the primer, but not a lot.
-cracked the injectors nuts again. Bubbles and fuel came out of 1 and 2, closed them once it was steady fuel. Cranked again until bubbles and fuel came out of 3 and 4. Fuel now coming out of all four. Tightened.
-recharged battery (overnight)
-checked voltage on all four GPs
-cranked with throttle all the way open ... it is not starting. It is now back to (what sounds like) catching on a couple cylinders and sounding like it's close to starting, but no go.
Also tried, for the heck of it:
-removed vaccuum line from shutoff valve
-removed crankcase hose in case it was maybe obstructed and causing back pressure

I am not getting a huge stream out of the return hose in the bottle when I pump the primer, but it is a small steady stream. I tried submerging that hose to see if air was coming out and it wasn't. I'm not seeing air bubbles moving through the hose on the back of the IP anymore (which I was getting yesterday), but there is a big fat air bubble sitting on the top of it, near the spin-on filter. Nothing happens to the air bubble when I pump, regardless of what bolt is cracked. It's just sitting there peacefully, and it got a little larger overnight. I'm assuming there is not supposed to be a bubble there? I can post a photo if it isn't clear which hose I'm talking about.
If my dad wants to stop by when he's done working this evening, I will try the WD40. I have not yet ... I assume there's not point in trying to spray it myself and then start ... it would just end up in a puddle in the air filter housing, right? I have a feeling it will start and just die out again, but I guess it is worth a try in case my bleeding efforts made any progress and there's just a little air left.
Only thing I haven't done yet is take the glow plugs out to watch them and make sure they glow fully ... guess I will try to do that now without burning myself or something else. Would also be easier with a helper.:(

Hope everyone is having a good holiday.:)

Update: It started again, and ran a while at part throttle ... better than the last time. Stayed pretty even at 1,500 rpm. When I tried to let off a little to see if it would idle, it quit.:( I can't see whether there's fuel and/or bubbles in my clear line. I made a video but it will take me the rest of the night to figure out how to get it on my computer.
That sounds like progress, but now I'm back to ground zero. Won't start again. Bubbles gallore. It's sucking them in somewhere. Again, all the bubbles are in the line between the pressure valve and the spin-on filter. A bunch of them moved through the line as I pumped, but now there's just that big pocket of air at the top again.
I guess the next step is to find the leak. There doesn't seem much point going through all the priming again until I've done so.

Looks like you have bled it well enough and it should have started. The fact it had not a hint of firing is baffling. Have you adjusted the valves since the last time it ran? Is the shut off lever on the IP in the correct position and not in the shut off position? I mentioned it before, that lever can be put into a position to not let fuel through normally (happened to me after a valve adjustment, which required removing some of the linkages).

Can't hurt checking the glow plugs for actual glow. Make a video so we can hear how fast your starter is cranking. The bubble getting bigger overnight indicates an air leak. There should be no bubble in any fuel lines after all air has been bled out from running the engine.

I suffered similar symptoms with an aftermarket, clear primary filter. The filter looks perfectly clean, but the inlet and outlet are of a reduced size and quickly restrict the flow. The lift pump is more than happy to suck air past the filter clamps. The clamps are capable of restricting liquid fuel from flowing..........they are not capable of restricting air from going the opposite direction.

Lesson cost $150............for a fuel pump that was not required.

Lesson learned: Use OE fuel filters.

Congrats! looks like it's an air leak problem after all! Try tightening the lift pump fittings and primer pump. Did you have the correct seals when replacing the fuel filter? Make sure those are clean and tight.

If you took the video on your phone, upload it direct to youtube need to register first) then post the link.

You can tighten until your wrist fails. It will not prevent air from leaking past the clamps under the condition of a inline fuel restriction.

How can you be so sure it is a inline fuel restriction? Even if the primary filter is a cheapo imitation, and the i.d on the barbs is less than 1/8", that is not enough of a restriction at idle for it to suck air. I can see if the filter is made from 2 halfs molded together, that the rough seam may cause a leak.

At this point, it's time to Mtyvac each component till the leak is found.

That would be a factually incorrect statement. The inlet and/or outlet provides the restriction with some foreign material of some sort.

.

Again, how can you be so sure it's a primary filter restriction? It can be that, or the hoses connecting it, or the lift pump, or the primer pump, its washer, or the hose between the lift pump and the secondary filter. Until each component is tested with a Mityvac, we won't know. Just because you had a bad primary filter does not mean BodhiBenz's also has a bad one.

Do you still have that cursed after market primary filter? I would love to run it and see what's the real scoop with it.

You asked two different questions. The first was whether I know if it is an inline fuel restriction. Of that I am certain.


The second, in this post, questions whether I can be sure that it is a primary filter restriction. I never stated with any certainty that it was a primary filter restriction. I stated that my own situation was a primary filter restriction. I cannot be sure of where the fuel restriction is other than somewhere between the tank and the lift pump. The primary is a good candidate to check first.

In my own suffering, I determined, finally, that the aftermarket primary was the culprit. It was not without a very expensive and time consuming lesson.

I did have it here and I was planning to photograph it and put it on the forum as a lesson to others. But, unfortunately, it disappeared.............:o

It would have made quite the experiment for you................

OK guys, here is the video I took earlier. It's not the greatest angle but considering I did it with the camera propped under the hood, it's not bad.:rolleyes: 240D trying to start/run - YouTube ... it sounds like it's nailing too but I guess that could be from the air. At times in the video it sounds like it's idling, but I actually have the pedal down a bit to achieve that. You can tell the times when I try to ease off the pedal, where the engine starts to shake and die out. I didn't shut it off at the end, just took my foot off the pedal. It would not start again, and as I mentioned sure enough I found lots of bubbles when I tried to prime.
The filter I put in is an MB filter from the dealership, but the hose is not (I got it from Pep Boys). The new filter and new hose both came after this problem started ... though that doesn't mean they aren't part of the problem.
I'll start at the filter and move downstream. One thing that puzzles me though is I have yet to see bubbles in the clear lines from the lift pump to the secondary filter, or secondary filter to the IP. Just in the one from the pressure valve. Maybe I'm just not seeing them because the lines are hazy, or they're zipping through there while I'm cranking or revving.

I have not been able to look at the video on a big screen so can't see any details of air bubbles. It sounded like it was running on all four so the good news is your injectors are ok.

You said: "I have yet to see bubbles in the clear lines from the lift pump to the secondary filter, or secondary filter to the IP. Just in the one from the pressure valve." Are those lines new? If they are old and brown, it would be difficult to see air bubbles. What did the clear temporary cigar hose replacement show? There should have been lot's of bubbles there when you had it running. That is the best place to look for bubbles, since all air ends up there (pri and sec filter, IP, injectors) Once you have solid fuel there and bubbles do not show up later, your fuel system is tight.

Don't forget the injector daisy chain return lines. They can leak and cause problems too. If you re-used the old lines and did not cut the ends back as a precaution, they are most certainly leaking. Best to just replace them with new from the dealer.

Unencouraging update: I changed and tightened the lines on the primary filter, with factory brand lines, and checked with a mitivac to make sure air wasn't getting past the primary filter connections. I also changed the return lines with new factory line. I'm just getting froth in the line from the lift pump to the spin-on now, and I can see little bubbles coming into the primary filter, but from the lift pump side (i.e., against the fuel flow). One end of the hose is submerged, it is tight on both barbs of the filter (and the filter looks unobstructed). The fitting is as tight as I could reasonably get it on the intake to the lift pump, and I cleaned that fitting before putting the hose on it. I'm considering replacing the primer pump and see if that helps. I don't know if or how they break, but it sounds like an air pump when I'm pumping it ... granted that sound could be coming from somewhere else down there. Is there a way to test which part of the lift pump is leaking? I don't have the money to just buy parts I hope fix the problem.

Lift pumps do not usually fail. Have you replaced the primer pump on the lift pump at some point? If so, that is the most likely place for air to leak in if you did not keep everything surgically clean when you replaced the primer pump. Before replacing the lift pump, I would remove the primer pump, take out the copper washer and either replace it with a new washer (very hard to find a new one the correct size), or take the old copper washer and heat it up red hot with a propane torch to soften it, clean it with 600 grit wet dry paper and surgically clean it. Also surgically clean the washer mating surfaces on the primer pump and lift pump before re-assembly.

X2
This is good advice.

If you wash everything around the lift & primer pumps so it is all oil / fuel free (may need brake cleaner or acetone), you could smear some non hardening gasket cement, or be rough like me & use spray glue (I suggested this many posts ago). If the air leak stops, you have found your problem.
I am not sure how the updated primer pumps work. Maybe some one could tune in with a cross section diagram. Just in case they can fail & leak air in.

I agree it is not a good idea to just keep on replacing parts till the problem is gone. ~That is the mentality of some of the dealer service departments over here.

Take pride in that you resisted the temptation to just blame the injectors. You have focused in on the problem & found where it is.

Using a non hardening sealant on suspected leaking joints to find leaks is a good idea. It may be hard to do in tight quarters such as the primer pump seal.

Don't forget the trick of cracking the fuel pressure relief valve banjo bolt on the back side of the IP during bleeding. It will really speed up the process. Instead of 150 strokes you only need 20 strokes. I use a 1 inch diameter 3 foot long tree branch with one end pointed to fit the primer a pump depression. Much easier than pushing with your fingers.

Thanks guys. I bought a new crush washer as they had one at the dealer. I will try cleaning the surface and using gasket maker on it to see if it makes any difference. Layback, when you say spray glue, do you mean the stuff you buy at an office store? I have some of that.
Here is a picture from Bosch that shows a cross section of the hand pump. Bosch Hand Primers I have to confess when I first went to prime the car, out of old habit (or just brain hiccup) I grabbed the pump and turned it ... maybe I damaged the spring inside or twisted the gasket inside of it. First I'll see if it's just the connection between the primer pump and lift pump though.

Tried replacing the copper gasket, and found two in there (I'd complain about the idiot who put a second one in there but I was the last to change it ...). Wiped it super clean and put the new gasket it in. No help. I took it back out and will try either the gasket maker or glue. Would this gasket be OK? http://www.permatex.com/products/automotive/automotive_gasketing/gasket_sealants/auto_Permatex_Form-A-Gasket_No_2_Sealant.htm. I can probably get that at Walmart.
Just to make sure my logic is right ... if there are bubbles in the line from the lift pump to the spin-on, can I narrow it down to: primer pump, fitting for line on line from primary to lift pump, line from primary to lift pump, primary itself, line from tank to primary? There isn't any other way air can get in to that line, is there? I also see bubbles in the primary filter, which makes no sense to me, because I tested that part of the system with the MitiVac and it held vaccuum. Maybe I didn't put enough vaccuum on it. I will try sealing all of it with gasket sealer anyway.
I did also try sticking the primer pump into a jar of diesel and pumping to see if air comes out. It does on the first couple pumps, but then stops. So I would assume the pump itself is not sucking in air.
I wish I could so this without getting so much fuel everywhere, it's making me sick, I think.:(

Yes thats the stuff I used. Rough but did the job. It may not be fuel proof but you are only using it as a diagnostic.
looking at that link, as I suspected the primer has a seal that could be bad. Pressurizing the fuel system through the return line with air is the way I prime most diesels now as there is no chance of air leaking in if its all under pressure. I resisted the idea of changing out my old original primer as I was concerned the new style could leak as well.
it does not look like rotating the plunger will damage anything.

You logic is good !
I hope you are doing this with good ventilation !! Like outside in the open air.
You have a nasty air leak there some place.
Sometimes I had to pump 1/2 a gallon of fuel through the system to get rid of all the air. The surprising thing in your case is that the air is not clearing once the car has started. @ 1500 rpm you are getting 750 pumps a minute of the lift pump. Are there any cracks in the hose fittings?

Good luck !!

1 item you did not mention where air leaks can get in is the lift pump. Rare but possible.
Only way to know for sure is test it or replace with a good unit.

FSM does not call for sealant on copper washers. Beware it will make removal and cleaning more difficult, especially in tight quarters such as the primer pump. I would recommend against it.

Where does the air enter the lift pump (other than the two fittings and the primer)? Unfortunately I don't really have the kind of money now to buy a new lift pump, unless I knew it was the problem. I'll keep playing with the hose fitment for now and hopefully find something. I'll leave the sealant off the copper washer.

Internally, the lift pump has a piston and a seal (an o-ring?) which is a potential area for air leaks if the seal/piston/cylinder wall is compromised. I agree you should not throw money at it.

I have a good used lift pump from a 83 240D if you want to borrow it. Just pay for shipping. Another thing you can try is bypass the lift pump altogether and supply fuel to the secondary filter with an elec pump, which you will have to acquire.

Just a thought, can you post a pix of your current setup? I'd like to see how the plumbing is hooked up, including the 2 quart fuel tank, the clear lines (to look for bubbles) etc. Maybe I can spot something unusual.

Thanks for the offer on the lift pump ... that would be a huge help if I can't find any leak in the lines. I will let you know.:)
Pictures ... it's hard to see in the photo but the supply line is thoroughly submerged in the diesel. I did wonder if maybe the line being routed up and over the bottle might be too hard for the pump to pull the diesel out, but I wouldn't think it would be any harder than getting it from the tank ... though the tank's hose is in the bottom of the tank so it has help from gravity.
http://compressionignition.files.wor...2280.jpg?w=450
If you look closely in this photo you can see where the fuel sits in the hose to the pressure valve ... all the way down near the first glow plug ... the rest is air.
http://compressionignition.files.wor...2279.jpg?w=450

I can't tell from the pic but the return line also needs to be submerged. You have no hose clamp on the return line, it needs one there to make sure it does not leak. Is there a hose clamp at the black supply line to the pre-filter? You must have one there for the same reason. I see you have rags all over to soak up diesel, in places that should be dry. During priming, the only place that should wet is the return banjo bolt that you loosened to bleed air. Any place else should be dry! If not dry, those are leaks and needs to be corrected first!

The fuel level in the brown line (pressure valve line) should be full to the top, all the way to the clear line, which must be full with fuel all the way down to the bottle.

The fact that the level of the fuel in the brown line is down to the glow plug suggests:

1. Priming was insufficient.

or

2. The pressure valve banjo aluminum seals are leaking and/or the pressure valve (ball) is not sealing.

or

3. The IP may have a leak somewhere.

I'd suggest wash off the diesel with Simple Green and water then let it dry. Stuff a rag tight under the pressure valve while bleeding, which is the only area that should be wet. Anywhere else that gets wet is leaking and needs to be fixed.

If you are going to wash it, cover up the opening of the bottle and be careful you don't get water in there. Stuff a towel in the opening and a plastic bag placed over it should do.

The red rag is there because that's where I was trying to bleed it ... the other rags are just there because I took this picture after I had removed the primer pump and I tried to cover up the engine mount.:) The one under the return line was from when I swapped those lines out ... not sure why I forgot a hose clamp, I'll add that. The return line is not submerged in the diesel ... I did not know it had to be. There are hose clamps where the supply hose connects to the filter on both ends and the fitting at the lift pump.
I don't see any fuel leaking other than when I take something apart, but it's getting pretty generally messy so a clean-up would be a good idea so I can see better. I will try that and also get a longer return hose so it can be submerged.

The return is 1 inch above the bottom of the tank so it is submerged until the tank is almost on empty.

Note that you may not be able to see tiny amounts of fuel leaks. A trick you can use is take white tissue paper and press it against the area you want to check for leaks and look for signs of wetting.

Quick question/observation: After sitting, all the fuel runs out of the line between the lift pump and secondary filter. It will rise again when I pump the primer, but after sitting for a couple hours, it's empty. I'm assuming all the fuel ran A) back into the lift pump or B) out the fitting on the going end of the lift pump. If it's A, would that be a failure of the valve in the lift pump? Fuel is not supposed to fall back into the lift pump, is it? I will do more cleaning to investigate the possibility of B first.
Also another question on bleeding via the pressure valve. Should I be cracking the larger bolt (17mm) or the smaller bolt on the outside of it (15mm I think)? I've been cracking the 17mm one and it does bleed out of it, but wanted to make sure I had it right.
I did also notice tipping the bottle to the side (thus reducing the amount the fuel needs to go up out of the bottle seemed to reduce the amount of air getting sucked in. Might have just been a coincidence but I'm considering trying to change the bottle setup (or just clean the tank strainer, tank vent and tank, which I'd have to do anyway even if I get it to start).

Keep the bottle till you have the air issue fixed. Put more fuel in it, keep it 3/4 full so both lines are submerged.

Loosen the 17 mm pressure valve banjo bolt just enough to let air out as you pump away. Once you get fuel coming out of that banjo bolt, tighten it and keep pumping till you get solid fuel into the clear return line, then crack one injector nut slightly and the engine should start. Feather the throttle to keep it running and get all the air out of the system. You should see foamy fuel in the clear line till all the air is out and the fuel should not drain down after you shut it down. If it does, you still have leak(s) which must be fixed.

Now you are getting to the bottom of things !!
Air leak on secondary filter.
It should not be causing air into the system once it runs though.
Running back does suggest the valves ( there are 2), in the lift pump may be weak but this should not stop it from running, if both the supply & return lines are under the fuel level.
You may wish to try that lift pump you were offered, or better still a rebuild of your lift pump. New valves may help, they should be cheap. Dont know what a kit would cost.
The seals on the secondary filter need investigation. The injector return lines should also be checked.
The inlet fitting to the secondary filter may have a leak.
I am just throwing out suggestions.
Good Luck !!

Check the smell of the engine oil and level on the dipstick. If the level is high and smells like diesel, the lift pump is leaking fuel into the crankcase.

Did you try the white tissue trick? Make sure all joints are dry first (per white tissue, then prime the system, try to start it, then go around with the white tissue again (every joint should be dry except the one you loosened while priming).

All the joints stay dry, though I checked with a paper towl (the blue ones) rather than tissue paper. It is pretty easy to see any moisture on those towels. But I can still see the air, despite following the procedure above, so it has to be leaking somewhere. I did add to the diesel jar and make sure both lines are submerged. I'm still thinking it doesn't help to have such a steep climb for the supply line out of the bottle but maybe I'm not understanding the physics of it.
I bought the lift pump rebuild kit since it was less than $5 plus bought replacement seal rings for all the banjo bolts. I also bought the little seal rings for the secondary filter bolt. Will try replacing those things, though I have not been very motivated lately.:rolleyes:
Edit to add: Engine oil level and smell are normal.

Don't worry about the steep climb. :D When you suck on a straw drinking a soda, isn't that's a steep climb? The lift pump can suck 100 times more powerfully than you are capable of.

One thing I'd suggest doing is check with the dealer by the p/n stamping on the secondary filter housing that you have all the correct seals installed. I understand there are different version sec filter housings out there, some have more seals than others. I think the air leak is in the secondary filter somewhere since it is at the highest point and you say that fuel is draining down the clear (brown) line between it and the IP.

Potential leaks at the sec filter can be:

Missing seal.

Dirt between seals and gaskets. Inspect (with a magnifier) all seals and their mating surfaces. Or test with MityVac

Cracked banjos from over tightening banjo bolt. Inspect with a 100x magnifier. Or test with a MityVac.

Testing with a MityVac is easier said than done unless you can rig up the correct fittings.


I'd suggest changing one thing at a time and test so you will know what the culprit is.

I now replaced (one at a time): the seal under the secondary filter bolt, and the rubber ring on that bolt, seals on the 3-way banjo fitting on top and the seals on either side of both banjo fittings on the secondary fitting. I also made sure the filter seal area was clean and all banjo connections were clean and inspected the fittings with a magnifier. No luck. It did start up without quite as much trouble after I replaced the filter seal, but alas, just filled with air again and left me back at ground zero.:(
After that I decided to take off the lift pump and inspect/replace the valves. I did notice some black stuff on the surface of the banjo bolts when I took them out, and there was black stuff in the primary filter (which is replaced now) so I think the whole thing was badly fouled with algae. Not seeing any of it in the fuel returns now that I've got clean diesel running through but maybe it's gunked up some internals.
I got the lift pump off, but wasn't quite expected the fountain of oil to come out?! Is that normal? I'm assuming this is just the oil in the IP, and will eventually stop pouring out? I just stuck the lift pump back on enough to get it to stop draining last night, and will address it today. Man did I make a mess. I'm a little confused about what I should be replacing once I got it off, after reading a few lift pump threads, but I guess once I take it apart I will have a better idea. I have the lift pump kit (valves and springs plus copper seals) and a gasket that goes between the pump and IP housing.
Also, should I try removing/inspecting the pressure relief valve while I'm making this big mess? It's the only other thing I can think of.

Diesel tanks and systems can have microbes such as Bacteria, Yeast, and Fungi, but there is no Algae.

Wow, your 240D is a stubborn SOB ha? Rebuild the lift pump first since you have the kit. Oil is IP lube and will stop draining, should not be more than 1/2 pint.

Yes, it's being a bit of a brat. Maybe it's rebelling because I left it in the back of the garage too long while the other cars had all the fun. I'll let the rest of the oil drain out ... I figured it couldn't be too much since most of the oil would have run down into the oil pan by now! When I put it back together, I take it I can just add some oil to the crankcase and the pump will just suck more oil back in when I crank, or does it need to be pre-oiled somehow?