The 300e had been sitting for 3 years when I got it. It appears to have a valve bad on cylinder 6, but that's irrelevant to this discussion. I'll also skip the other irrelevant problems.
We ran out of gas.
After adding fuel, it started but died when I tried to move. I suspected the fuel filter being clogged.
Replacing the fuel filter caused 2 hoses to crack. I replaced them too.
It finally started. (It took a while to fill the system with gas I think.)
I drove it a block, heading to the gas station because I only added 1.5 gallons. It died.
I can't restart it. And I have to (beg for) jump it to even try that.
I think maybe I clogged the new filter. It's definitely a fuel problem.
This page explains the pressurized fuel system.

I'm headed (by bus) out to it again today. I just want to take the battery to get it charged. I also plan to speak to the people whose house it's in front of. I don't want it towed.
BTW, I never got legitimate tags for it. I just used the ones from my old car. Consequently, I can't leave it parked indefinitely. It's currently in a rather upscale neighborhood.
Ideas? Comments? Moral support? Please.
It's very difficult to work on where it is. I don't have another vehicle, meaning, although only 10 miles away, I have to get there by a long bus route. I don't have a friend who can help in this town. A real tow cost about $100, which I don't have. I'm trying to find someone I can pay who will pull it with a tow-rope.
I'm thinking maybe I have to remove the new filter and blow it out backward with compressed air. If I do that, I'm afraid to clamp the hoses because I damaged them last time. I also hate to lose the gas I already put in.
I can save the gas by draining it all in a pan, then running it through filter paper, then re-filling the tank. But all that is hard to do when you have to carry all the tools to the site on a bike & bus. I dare not leave tools at the car because it may get towed. I really need to rope-tow it home.
I'm in Kansas City, BTW. It's an unforgiving town when it comes to impounded vehicles. Once, a cop _didn't_ ticket & tow me because he said he didn't want to see me lose all my tools. These would be stolen at the impound yard, it's assumed.

 

But the time I returned to the car's location, the car had been towed by the Gladstone, Missouri police. The impound yard, Glad Rents, charges $40/day in addition to the towing fee. Plus, I'd still need to tow it home. I gave up on the project. I'm going to concentrate on getting my original car (2001 Mercury Sable) back running. It's a shame because I put so much effort into the Mercedes (even to the point of making myself physically sick). But a valve is bad, the oil pressure is low, the cooling system has a problem, etc. If I had spent that effort on our Mercury, I'd have it running by now.