Every car is different. The car that you are talking about might have low compression or other issues( clogged filters, clogged strainer, etc). My 84 starts right up. If it is cold outside, like 30-40 degrees, it cranks a for 2-3 seconds and you might have to throttle it a bit , but it starts, and within 2 minutes it runs perfect. My wifes 86 SDL ( OM603 motor) starts even easier, and runs even better, but they are different motors, different injection pumps, bigger battery, etc...
I regularly use the Lubromoly diesel inj cleaner. I buy it by the case. I change the plastic filter, and use lubromoly every oil change or sooner, and clean the Lovecraft filter every 1500-2000 miles. No issues.
I understand that the best setup is a two tank system, and I have the valves and lines to make it a two tank but since it works fine, why bother. The only thing that used to bother me was the supposed coking of the piston rings, but since I am not getting any blowby, or loss of power, or gelling, I am not worried about it. I adjusted my valves 2K miles ago, head looked great. I changed my oil pan about 4-5K miles ago because it had a big dent, and there was no gelling in the pan either.
My oil level is always perfect, car barely uses any oil between oil changes. About 1/2 quart between oil changes, with a slight oil leak, on the big pan.
So i am just driving it and that is it. The 84 300D has faded paint, red interior, it slow, but it runs, and its free, so that is all it matters.
I also have 2 spare motors apart ( OM617) so I am ready for a rebuild if something happens.
The price of an engine rebuild on the OM617 is $500 ( valve job, rings, gaskets, timing chain, tensioner) or so its cheaper for me to keep driving on veggie oil, and build one of the spare motors than spend money on diesel or gas.

A private message I recieved and my answer. Although he was smarmy, he cleared up my questions which is all I was seeking. I guess he buys and sells cars, which is perfectly fine. We all seem to have a few extras laying around.....
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I don't really care about your fleet. I am looking for a W124, gas or diesel and saw both your ad here and on Craigslist.
A search of things you may have posted on about your car turned up info that logically raises questions.
Nothing more than that......
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__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

Bought too many, now gotta sell some.

See, we finally have something in common!

Since I don't know you from Adam, my line of questioning wasn't personal. We have all kinds of folks that try to sell cars on here so we must try our best to do our due diligence....

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

Thats fine

My wife dont want to sell the white 1991, she says the SDL is slower and more difficult to drive, but the 1991 wil bring more money in, so that gotta go.
SDL drives really nice though, its a long base S class

Well, I hope it brings what you're asking. I don't see any right now bringing that type of premium $$$$, but you never know. Good luck, and if the price ever drops to more of a "working class" level I might could be a player then.
I have no doubt the wife would much rather drive that then the extended W126!

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John