Injection system — check (Audi A6 C5)

It is almost impossible to check the fuel injection system yourself, as this requires the appropriate measuring instruments and a good knowledge of the system. To perform numerous measurements and take readings, special adapters and plugs are needed so as not to damage the contacts. However, in the event of a system failure, we recommend the following:

1. Make sure the ignition system is normal if the engine does not start or stalls.

2. Check the power supply system and battery charging.

3. Perform a visual inspection of the condition of the injection system components, including checking the condition of the air filter. A dirty or clogged air filter element significantly affects engine performance.

If after performing the above actions the cause of the malfunction has not been established, then read the list of possible malfunctions of the fuel injection system and methods for their elimination, and also contact the workshop to print out the malfunction codes registered by the control unit. Based on the data obtained, establish the cause and check the corresponding part.

Caution: In the event of a sudden complete failure of the fuel injection system, first check the fuses.

Leakage in the intake manifold leads to the entry of "side" air into the system. The amount of this air is not included in the parameters stored in the memory of the electronic control unit and its entry leads to failures in the functioning of the system. Excess air leads to uncontrolled depletion of the air-fuel mixture.



4. Check the condition of the vacuum supply hoses and their fastening on the connecting fittings. It is necessary to check all hoses on the injection system and the intake manifold (brake booster hose, heated air supply hose, fuel vapor recovery system hoses).

5. Warm up the engine if it starts but runs erratically or with failures, and let it idle. Open the hood.

6. Spray the injection/engine control unit in the area of the flange on the intake manifold side, the sealing gaskets of the intake manifold pipes, and the hoses of the units generating the reduced pressure with the so-called starting fluid. Disconnect the lambda probe plugs.

If, when applying the specified liquid to a certain part, the engine speed increases, then this is the place where air is being sucked in.

7. Make sure the fuel hoses are tight and the ground (-) wires are securely fastened.

8. Make sure that the connector plugs are seated properly and that their contacts are not broken or bent. If necessary, spray the contacts with an aerosol to improve the conductivity of the contacts. Do not bend the contacts themselves.