Hello all, I'm new and have a few questions. My grandfather recently passed away and I am now in posession of his 1980 300TD. The car is in VERY good condition, but has been sitting for several years. I jumped the battery and she fired up without hesitation. She purs but is the slowest thing on 4 wheels. For some reason there is a NON turbo engine in this car. My questions are...what should I do to tune her up (never owned a diesel before)? I also notice that there seems to be fuel leaking from the injectors. Is there a cheap way to do a turbo conversion and give her some more power? I've had several Ford Thunderbird TurboCoupes in the past and I am familiar with upgrading turbo's etc. I just never have with a german diesel and don't want to spend alot of money. Thanks in advance for any help.

 

Any Ideas on where I might be able to find the cloth fuel return line? Also where could I get new fuel injector O-rings? Does it have them like regular gasoline vehicles. The diesel is coming out at a contstant drip. All the lines are saturated and it looks like its also coming from the base of the injectors? I just read the horsepower rating and its a whopping 87 HP. WHY???? would they do this to such a heavy vehicle. I'm just curious since I thought all the benz diesels were turbo.

 

Thank you for the in depth answers!!
I'm thinking of sellling it in a little while, but wanted to get rid of some of its "issues".

 

After working on the car for a few hours tonight, I have a couple of more questions if you don't mind.
- When I get the new cloth/braided feed lines is there a link or somewhere I can look so I know what I'm doing?
- The rear shocks are shot. Can I replace them with something aftermarket?
- Is there a way to adjust the gas pedal? You have to floor it and push as hard as possible to accelerate. Top speed so far seems to be 50 mph. She doesn't sound or feel good at all if I try to go faster.

Thanks again for all the help!!!

 

Mine has a turbo and was deadly slow until I adjusted the Throttle Linkages. You pretty much described the same symptom of having to have the Pedal almost to the floor to get it to go fast.
Under the Hood; if you follow the linkage that comes up from the pedal to the Bell Crank that is on the Fire Wall; be, sure to check that to see if it has a lot of play. There is a big plastic ball/bushing behind it that falls apart with age and the rubber part in the front also can rot out.
If you flollow the steel rod that comes off of the Bell Crank forward you will come to 2 parts of the Linkaged bolted together with a 10mm bolt. One of the parts has a slot. Loosening that 10mm Bolt and adjusting the sloted part will take up some of the slack in the linkage.
Some places to get the Braided return line are NAPA, VW Dealer (used for the 80s VW Rabbit Diesel) and of course the Mercedes Dealer.

I have tried the below myself:
Vacuum Hose fits but will only last a week or so before the Fuel eats through it.
Silicon Vacuum hose will work and and not leak but by the end of the year will be hard as a rock.

I would advise learning how to bleed the Air out of the system before you change any Fuel Filters or run out of Fuel.

The Valve adjustment is also in the above threads.

 

Thank you for those links. Its so great that we're all here to help and share. I did the same think for many years on a Thunderbird turbocoupe owners forum. It kills me to know nothing about these cars.
I was reading a few posts about the suspension and now hoping its not the shocks but maybe something cheaper?? The car sags in the rear all the time and never raises. Any suggestions on where to start and what to check first???

 

I just noticed that there is a container near the front of the engine bay on the left. In front of the air cleaner. This container is EMPTY and smells like oil when I open it. Is this the hydraulic fluid reservoir? It just dawned on me now after reading through all of the posts about hydaulic fluid that there must be some place to fill it. I'm going to try filling it and seeing if I can locate a leak somewhere. There has to be one if its empy????

 

I have never looked under the Hood of a Mercedes with the SLS. But, people often overlook the obvious.
If you trace the Hoses or Tubings and see where they go you will find out what it is used for.

As you face the Engine if you were standing in front of the Car the SlS Hydraulic Pump is bolted to the sort of upper Right Front of the Engine on the Drivers side of the Cylinder Head.

If you trace the Hoses or Tubings to the Empty Tank that will tell you what it is used for.
I do not know if you need special Oil for it or not.

 

I found that indeed that is the reservoir for the hydaulic fluid. I put in DOT4 brake fluid so I can find the leak and the fluid poors out from the lines themselves just above the rear axle. They are all corroded. At least its not the other stuff, but I'm going to have to rig up new lines going back to the system to make it all work.

I got the cloth covered fuel lines and the change over was 10 mins and the car runs a lot better now.

I also adjusted the throttle linkage and it moves alot quicker than a few days ago. I'm getting there!!

 

I needed to put in something to find the leak and that worked. I need to replace the entire metal lines going back to the unit behind the rear axle. They are all rusting and the fluid just spewed out. When I run new lines or find a way to fix it, then I'll put in the correct fluid. (thank you so much for that link!!!) I would have just wasted my money this time around. Thank you for looking out though!!

I'm fixing other little odds and ends things right now also. The defroster works perfectly and so does the AC compressor, but the fan hi and fan lo and bi level setting do not work. the speedometer and the other gauges work, but the clock and mileage counter and trip odometer do not work either. Any suggestions for these??