I really need help with an OLD 107
 

I hope you all can help.
I started the 73 450sl today, just getting started to load it on the trailer to go to the wash and degrease it. It always starts and it did but ran real rough. Warmed it up and put some Lucas injector cleaner in the gas. Did not smooth out. Backed it back into the garage, removed the fuel filter just to check it out. The filter seemed fine, blew through it both ways, seemed easy.
Reinstalled, removed temp sensors and cleaned with carb cleaner and reinstalled. Removed throttle control sensor wires and cleaned. checked for vac leaks. NOW it will not start. I put fuel in the intake it will start fine and run until that fuel is used. I checked the fuel pump it does not run when the key is on or when my LOVELY WIFE is turing the key. But the pump will run when I apply 12v directly to the wire lugs on the pump. WHAT is wrong?
What controls the fuel pump? ANY help Thanks

When is the fuel pump suppose to run, when the key is turned, when you are cranking the engine, when the engine is running? The pump would not run when key turned or when cranking only when 12v applied directly. I hooked the + to the red canvase coated wire and the - to the brown non canvan wire but it did run and ran strong. But no start. Help

Fuel pump relay?

Fuel pump relay. Not sure on a 73 but on my 80, putting a jumper between sockets 1 and 2 on the female plug side will bypass the relay and should start the car when cranked.

I do not know where scoket 1 and 2 are located, I do not know where the fuel pump relay is located on a 73 450sl. I have been waiting 3 months for a CD maintenance manual still is back ordered. If someone can tell me where the fuel pump relay is located will really shorten my quest. Thanks

Located near the fuse box. Go on ebay and buy a CD, you'll have it in a week. While your at it you could pick uo the relay also, what you save in the cost of the relay it will pay for the CD.

My fuse box is next to the right foot of the passenger. I will take a look. I have looked at the fuses they seem to be fine, in doing that I never noticed any kind of fuel relay in the interior of the car. thanks

Is there any more help out there?