- erroneous actions when starting the engine must be excluded;
- there must be fuel in the tank;
- fuel system pressure and compression are normal;
- the battery is charged;
- the starter rotates with sufficient speed.
Almost all faults in control electronics can be determined only with the help of special control and measuring instruments.
Caution: If high pressure fuel lines are removed, they must first be cleaned using a cold cleaning agent.
The engine does not start or starts poorly
The preheating system does not work
Check the preheating device.
The fuel shut-off valve does not open
Check the fuel shut-off valve, engine control unit, and anti-theft system unit.
Fuel is not supplied in sufficient quantity. The fuel supply system is faulty
Check if fuel is supplied:
- a) fuel hoses are pinched, clogged, leaky, porous or have a loose fit
Clean the fuel lines:
- b) the fuel filter is clogged
Replace the fuel filter:
- c) the fuel tank ventilation is clogged, the mesh filter in the tank is dirty
Clean the ventilation and filter mesh.
The engine runs jerkily at idle and when starting off
Weak fuel hose connections
Replace the fuel hoses, secure them with clamps, tighten the hollow bolts.
The fuel supply and return lines are reversed
Information copied from the website [MERCEDESMAN]
Check the fuel line connection.
Fuel is not supplied in sufficient quantity. The fuel supply system is faulty
Check if fuel is supplied:
- a) fuel hoses are pinched, clogged, leaky, porous or have a loose fit
Clean the fuel lines:
- b) the fuel filter is clogged
Replace the fuel filter:
- c) the fuel tank ventilation is clogged, the mesh filter in the tank is dirty
Clean the ventilation and filter mesh.
Too high fuel consumption
The air filter is dirty
Replace the air filter element.
The fuel system is leaking
Perform a visual inspection of all fuel lines (feeder, outlet and main), fuel filter, fuel injection pump and high-pressure fuel pump.
The fuel return line is clogged
Blow out the return line to the fuel tank.