1985 Mercedes Benz 300dt Wont Start

first of all if you been using starting fluid to start it you have probably burned a glow plug or 2, the glow plugs are really easy to check you will need a test light, on the left fender behind the headlight there is a box or the plug-in you will see five conductors each one of those go to the glow pugs take your test light and put it on the ground post of your battery bank check every connection on the glow plugs, if the light does not come on the glow plug is burned out they are numbered one through five and your engine starts at first cylinder which is number one and goes back to number five. now your fuel leak, check the small return hoses from injector to injector those may be leaking and causing the little puddle of fuel under the car you can also pressurize the fuel system by using the hand pump which is located right on the injection pump, it is a small knot that you turn out and then you can push it in and out like when you run out of fuel that will pressurized the system and you can check for fuel leeks. that should keep you busy for a little while anymore problems let me know.

I had to write you again because I misled you on checking the glow pugs, I told you for the test light on the ground side of the battery that was a mistake, make sure you put the test light on the positive side of the battery, the light will come on if the glow plug is good