Diagonal inop windows usually mean a fuse. Check one of the ones in the corners, they've got letters a-d, not numbers.

The alternative fuels forum has info for future plans. There are a few techniques for draining or flushing the tank. There's a fuel strainer that you may want to swap. Possibly consider new viton lines if you're going bio-D or WVO.

Clean and check fuses. Clean the crap out of the hinge drains. Check your front suspension and read up on the M-B spring compressor. Welcome to W123 ownership.

Thanks for the tips. As far as converting to wvo, I will be using a two tank system. I am not sure how to plumb it yet, but I did convert my 7.3 powerstroke 90,000 problem free miles ago. I used a kit for the conversion but have gained a fair amount of knowledge since then. I will be doing a DIY for the Benz. I am real happy to have this car and eager to learn more about it. Hoping to find a wagon someday.

W123 vacuum interlock diagram
 

Here is a post from a thread on the w123 vacuum Interlock diagram.

http://www.peachparts.com/shopforum/1247118-post5.html

Charlie

Thank you, that is very helpful. Is my car a w123?

It is.

Okay, thanks. I can't see how it would make a difference, but, I noticed in the diagram that the yellow splitter is on one of the outer branches of the 3 way part of the vacuum line, on my car it is on the center of the 3 way split. I'm sure it shouldn't matter but thought I should check.

Also, I am having difficulty find the fuse box. I found a box with a couple of relays but no fuses.

Hmm
 

Hmm, if you still haven't gotten it started, try a carbon reamer. You take out the glowplugs and ream the carbon out of the glowplug holes. Here is a site that you can buy the reamer from, and they tell you tons of info. Good Luck!!

https://**************.com/node/2842

Fuze box
 

The fuze box on my car, I think it would be in the same spot on yours, is next to the brake booster. Right under the hood, driver's side, little black cover with two long screw-type-things. If you need, I can take pictures of mine. Again, Good Luck!!

The only thing important is that line getting full vacuum. The two nipples on the main vac line may/should have different amounts of vacuum. ~22 and ~15 inHg. You want as much vac as available.

As far as fluids go, that's usually a can of worms, but I just switched to synthetic. Just be sure to use a diesel rated oil.
Otherwise, I use name brand stuff available at the local AutoZoo.

I've use Bosch glow plug. Stay away from Autolite!

There is the Factory Service Manual available sometimes online, but I bought mine from MB. They are more difficult to track down now, but should be around.

The fuel system will need attention. At worst a tank flush. As mentioned, there is a strainer in the bottom of the tank, it can be cleaned and reused. You'll go through a few filters at first too, both the clear inline one (primary) and the spin on one (secondary). On the banjo bot holding the spin on filter, there are two rubber "O" rings, replace 'em.

Replace the fuel cap. I use an oil cap I picked up from the junk yard. You can get new a gasket for it. Water, condensation, has spent some time in the tank, so at least a dewater treatment, then a fungicide is a good idea.

This antifreeze:
Valvoline.com > Products > Zerex > Antifreeze Zerex > Zerex G-05® Antifreeze / Coolant

DOT 3 or 4 for the brakes, do not use silicone based stuff, it doesn't mix well with what's in there now.

The fuse box has two large knurled knobs on it, it takes some time to get it back on, but clean the contacts and replace all fuses. It is on the fire wall, beside the brake booster. See pic.

Someone mentioned to use a reamer on the glow plug holes, see pic.

Thank you for the good information. It really helps a lot.

Yes!
 

Yes, somebody was able to get a picture! Sorry about that!! Good Luck and God Bless!

82 300d and 84 300d interchangeable?
 

I have an opportunity to pick up an 84 300d for real cheap. The body is a bit rough, but it has a lot of new parts. The parts would swap out with my 82 300d right?

Not all will but certainly most will.

So what else besides glow plugs would make the car really hard to start? Once its started it idles real low and rough. Once the car has been driven and warmed up it seems to start no problem after cycling the glow plugs, hard start if I don't cycle the gp's. Is there something else I should check out before changing the gp's. Thank you. It is also very slow acceleration until I going 20 or so.

Welcome! I'll probably get howled at for this, but it's something my wife noticed about the shifting on ours. If it starts getting low on oil, it shifts later. I thought she was goofy, but I have to admit she's right. Since mine has a few leaks and blowby issues, I do have to ad oil after long trips. And those glow plugs definitely need changed. Even if they test good, you can keep them for back ups, but just starting out, I'd change them all. Also, everybody has mentioned the vacuum issue, but if this has set for years, I would go through and not only check for cracks, but for then ends of vacuum hoses that can dry rot and not have a tight fit anymore. (Been there, done that). The two yellow lines are leading to doors, trunk and fuel door locks. I don't even use my trunk or fuel door locks. Might want to look at your engine\tranny mounts. That might have a little to do with your rattling\shaking issues. (Also the engine shocks). There are also small (cheap) bolts that hold the air filter housing on that can make lots of noise if loose or broken. Another thing to check for rattling are the exhaust hangars, which are basically rubber donuts (cheap and easy, also). If they're gone or dry rotted, get new ones. To make them easier to put on, put them in a pan of hot water for a few minutes. That will help there. Ok, then, good luck and expect to get answers and help like you wouldn't believe on this forum. It's been a real life saver for me! Good luck! Lee