Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
Hi Ernest, my name is***** has been done to the car so far? Is this a 4 or 6 cylinder?
Ok, first I would check the fuse in the overvoltage protection relay located behind the battery. The fuse in the top of the relay powers the engine management system. If the fuse is good the next step would be to clean out the fuel system. I'd start by draining the tank and inspecting the screen inside the fuel tank for rust. If the tank is rust free you can refill the tank with fresh fuel and replace the fuel filter. I would also use a fuel additive to help clean out the fuel injection system. The most common failure on the fuel system when the car sits for a long time would be the fuel pump and the fuel distributor. Ideally a fuel pressure test should be performed to check the fuel pump. The fuel distributor is the main unit under the air cleaner that distributes the fuel to the cylinders. This unit tends to gum up due to old fuel. Running the motor with fresh fuel and a good fuel additive will sometimes be sufficient to clean out the fuel distributor but in many cases the fuel distributor will need to be replaced. If the car ran fine years ago when it was parked it is unlikely that you have any ignition problems. I recommend BG 44k fuel additive. Cleaning or replacing the spark plugs is a good idea but most engine running problems are going to be due to the fuel injection system. It would also be a good idea to check for vacuum leaks at the intake manifold.
Let me know if you have any questions.