My 102 103 104 Gas Engine Just Won't Start

There are a number of reasons - don't throw money at the problem - diagnose first!!!

These 201, 124, 126 and 129 chassis engines can be temperamental when they reach high mileage or if not maintained properly.  Make sure you have GASOLINE in the fuel tank! Start with the simple things first like spark plugs and spark plug wires (unless they have been recently changed).  You won't be wasting money as this should be a regular service item at least every 60,000 miles.  Take a close look at your cap and rotor.  Look for corrosion where the wires plug into the cap. If you find the problem is with fuel delivery then you have some detective work to do first. The fuel injection system is not simple, but must be diagnosed first when dealing with a no start condition. If you think, or know, it is a fuel related problem (rather than ignition spark) then start with the back end of the fuel system first. Check to see if you are getting power to the fuel pump. If not check your fuel pump relay if your car is so equipped. Next you will need to look at your fuel pump, fuel filter, check valves and accumulator. Kent calls that the back end fuel delivery system for clean start.

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Problem & Solution

Common among these chassis:

W124
W126
W201

After checking all that, you will need to properly test your engine injection system and that may require you to take it to a shop for diagnosis. 

Click here to read more about 102 103 104 Engine Back End Fuel Delivery System.

Kent has a series of videos he has produced on no start and hard starting. All are listed here.