- a) Incorrect actions when starting the engine are excluded. Do not press the accelerator pedal either when the engine is cold or when it is warmed up. After starting a warmed up engine, it may be necessary to "step on the gas" a little;
- b) the tank must be filled with fuel, the engine has no mechanical damage, the battery is charged, the starter rotates with sufficient speed, the ignition system is in good working order and adjusted, the fuel system is sealed, there is no contamination in the fuel supply system, the crankcase ventilation is in order, the electrical ground wire (-) (engine - gearbox - body) connected. Interrogate the self-diagnostic system at the workshop and print out the codes of possible malfunctions.
Warning! The fuel system is under pressure. If it is necessary to disconnect the fuel lines, place a rag on the joint and clean the connection points with a cold cleaning agent.
The engine does not start
The fuel electric pump does not work when the starter is turned on (i can't hear his noise)
Check the voltage supply to the fuel pump. Check the contacts.
Fuel pump fuse defective
Check the fuse.
Fuel pump relay is faulty
Check the relay.
No power to fuel injectors
Check the power supply.
Cold engine starts poorly. Runs unevenly
Coolant temperature sensor or intake air temperature sensor is faulty
Check the sensors.
The engine stalls
Fuel pump power supply wires broken
Check the fuel pump plug connections and the relay. Check the fuse and contacts. Clean or replace them.
The fuel filter is clogged
Replace the fuel filter.
The fuel pump is faulty
Check the fuel pump.
The valve injector is faulty
Check the valve injectors.
The engine operates unstably in transient modes
Material taken from a web resource [MercedesMan.ru]
The air intake system is leaky
Check the air intake system. To do this, leave the engine idling and lubricate the joints and seals of the intake tract with gasoline. If the number of revolutions increases dangerously, eliminate the leak.
Warning! Gasoline vapors are poisonous. Do not inhale!
The temperature sensor is faulty
Check the coolant temperature sensor or intake air temperature sensor.
The fuel system is leaking
Visually inspect all connections on the engine and electric fuel pump. Tighten all threaded connections.
Hot engine won't start
Fuel system pressure too high
Check the pressure and replace the pressure reducing valve if necessary.