Table of contents: The engine does not start or starts… ↓ The engine runs jerkily at idle and… ↓ Too high fuel consumption ↓
Before troubleshooting, the following conditions must be met.
Erroneous actions when starting the engine must be excluded. There must be fuel in the tank, the pressure in the fuel system and compression are normal, the battery is charged, the starter rotates with a sufficient number of revolutions. Contact the workshop to read the codes of faults registered by the self-diagnostic system.
Caution: If high-pressure fuel lines are removed, their joints must first be cleaned using a cold cleaning agent.
The engine does not start or starts poorly
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) in winter. The fuel in the filter or pipes has frozen or thickened;
Park the car in a heated garage. Check the condition of the fuel filter heater:
- d) the fuel tank ventilation is clogged, the mesh filter in the tank is dirty.
Clean the ventilation and filter mesh.
The injectors are faulty
Check the injectors by loosening the high pressure fuel line union nuts one by one and make sure the cylinders are working.
The engine runs jerkily at idle and when starting off
Weak fastening of fuel hoses on the injection pump or on the fuel filter
Replace the fuel hoses, secure them with clamps, tighten the hollow bolts.
The fuel supply and return lines are reversed
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) in winter. The fuel in the filter or pipes has frozen or thickened. Check the condition of the fuel filter heater;
Park your car in a heated garage.
- d) the fuel tank ventilation is clogged, the mesh filter in the tank is dirty.
Clean the ventilation and filter mesh.
The injectors are faulty
Check the injectors by loosening the high pressure fuel line union nuts one by one and make sure the cylinders are working
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 (supply; branch and main).
The fuel return line is clogged
Blow out the outlet pipe from the high-pressure fuel pump to the fuel tank.
Increased idle speed or maximum allowable speed
Check. Print out the codes of faults registered by the self-diagnostic system.
The engine has mechanical damage
Check the compression or overhaul the engine. Remove dents in the exhaust system.
(The original source of the article can be found on the website: AUDIMANUAL.ru)