So,

I bought a 1985 500 SEL. Beautiful black. Bought it Thursday. It has been driving fine. Small puddles of oil and tranny fluid on the floor.

The previous owner recently replaced the tranny with a used one.

I have put about 200 miles on it. Tonight, on the way home from work, and on the expressway at 60, The front end start shaking violently. I knew I had a bad tire, so I thought the tire blew out. I coasted off to the side, as the engine died. The car would not re-start. The tires are fine. The oil is still golden in color. Removing the valve cover cap, the cam shaft visibly turns fine. The tranny fluid is red and fine. No silver. The radiator fluid is fine and still green, with no milky residue. No fuses seem to be blown. The engine turns over fine. Not too easy, not too strained. I could not tell if it was getting gas, because it is a 5 litre engine, and has a big flap on the carberator. I pushed down on the flap and tried to peer into the carberator, but I saw no gas with a crank-over. Perhaps the gas squirts under the second flap which is the butterfly one?

Any ideas?

 

You don't have a carb, probably the old school fuel injection and the TB sits on top of the engine and has an air cleaner like a carb car would. When you say shaky do you mean it was a suspension shake or was it the engine? could be fuel starvation. A bad tire would cause the shaking you describe. Could be the FI, fuel filter, vacuum problem a lot of things. Find and good benz shop that has been in business before 85 and let them find the problem.

 

You didn't run out of gas, did you?

 

Good point, Lugnut running out of gas, never thought of that

 

It's not out of gas; has half a tank.

 

i know there is a carb version of this, but can you give us the VIN just to be sure?

fuel pump is working?

 

WDBCA37D6FA153018

 

Take a look at the electrical wire of the 02-Sensor,
because it can come into contact at times with drive shaft causing a short in the printed circuit board of the fuel pump relay.

If indeed this was the problem:

To fix it, Replace 02-Sensor, and make sure electrical wire is properly routed.

You also may need to Replace fuel pump relay.

Hope this helps

 

If the above was not the problem, then........


Check the fuel pump relay and A/C compressor control unit,

These can become defective because of corrosion.

Moisture can enter the relay via the vent bore in the plastic locating pin on the relay.

Relays of later production do not have this vent hole.

Before installing a replacement relay, check whether this vent bore is closed. If not, close this bore in the plastic locating pin with an adhesive (RTV or similar).

Hope this helps

 

not carburetor. your system is fuel injected.

loosen up one injection line from the fuel distributor and crank the engine. see if the fuel is coming out.