The injector fuel supply system and its errors P0172 and P0171

The injector fuel supply system began to be used in cars in the 80s of the last century. Previously, the carburettor was responsible for supplying fuel to the cylinders. For today, all modern cars are equipped with injectors, according to Euro5 standards.

Firstly, let us consider the features of the injector system. So, the injector is responsible for supplying the air-fuel mixture to the engine cylinder. The injector has an electronic type of nozzle control. According to the data reads of sensors (modern injectors have up to 8), the frequency and quantity of fuel-air mixture supply are monitored.

Based on the foregoing, injection of the fuel delivery system divided into: mono injection and control injection or direct injection for each injector.

For example, the system has a very complex structure, and therefore the repair and diagnosis are complicated.

Air intake and fuel mixing occurs through the throttle assembly (it is the throttle that is controlled by the accelerator pedal).

Fuel tank ➟ Fuel pump ➟ fuel drive (and drain fuel drive) ➟ fuel pressure control ➟ fuel rail ➟ injector nozzles air filter ➟ throttle valve ➟ intake manifold ➟ engine cylinder. This is a simplified example of how the fuel supply in the car works, in addition to the functionality of the injector system spacer ring, gravity valve, back-pressure valve are also important.

Initially, the injection system worked on the mono injection system, it was advanced of the down-draft carburetor functionality, but under control via the ECU. However, the mono injection for cars is not applied on up-to-day models.

Distribution injection also has several variations, therefore, more common in modern cars. For example:

• Direct fuel supply
• Simultaneous supply of fuel
• Pairwise-parallel fuel supply
• Phased synchronized fuel supply

Considering the complexity of the system, it is necessary to pay attention to the maintenance of the system and quality fuel starting from the 95th, although today the injector system is reliable and of high quality.

🔹Errors P0172 and P0171

Signs of error P0172-Rich mixture (lack of air)

• Firstly, there is an active signal "Check engine"
• Claps and shots from the silencer when it comes out black or gray smoke
• Increased fuel consumption
• Failures in the dynamics of the car
• Black soot on the plugs (norm brown)
• The car won't start

In the initial stages, it will be easy and relatively inexpensive to fix the problem.

Signs of error P0171 - poor mixture (not enough fuel)

• Firstly, there is an active signal "Check engine"
• When driving the car stalls
• Violation of the dynamics of the car
• Unstable "flapping" exhaust
• The light colour of soot on the plugs

The problem may lie in the malfunction of one of the injector sensors, or even a violation of the throttle valve, which only needs to be cleaned.

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