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Reasons and symptoms of malfunction of the fuel system

Fuel Tank

Fuel tank is – is the capacity for the safe storage of certain types of fuel, preventing its leakage and emissions due to evaporation.

There are various reasons for the appearance of dirt in the fuel and the main ones are:
- Produced water in the fuel.
- Presence of oxidants in the fuel, leading to fuel tank corrosion occurrence.

Consequences. The appearance of the dirt in the fuel has a very negative impact on the operation of the engine and the vehicle as a whole. It implies reduction in engine power, outages, jerks when driving at a constant speed and idling.

The fuel tank in use does not require special regular maintenance, but as preventive measures, it is recommended to drain it from the car once every 2-3 years and clean the condensate with special fluids.

The fuel pump (fuel pump)

The fuel pump is designated to send fuel from the tank to the vehicle’s engine. The main task is delivery of fuel at a certain pressure that is needed for the engine to do its job.
Fuel pumps work under pressure, so they are quite noisy and heat up fast. Hence they are placed in the fuel tank - the fuel cools the fuel pump and suppresses the noise.
Fuel pump grid gets clogged
Most car owners do not pay enough attention to the fuel grid. When the grid gets clogged the fuel pump starts to work in the mode of fuel shortages. So the cooling of the pump occurs due to the fuel that is going through it, then shortage of fuel can overheat pump’s parts, leading to its failure.

Vehicle stalls because the fuel doesn’t get to the final destination.

When the fuel grid gets clogged.

A clogged fuel grid begins to slow down the fuel supply. In this case the fuel pump acts as a ‘supercharger’ of pressure, taking the burden of the operational process. Attempts to ‘pump’ fuel through the fuel grid are undermined by the lower filter capacity, which leads to greater resistance when pumping fuel. As a result, the pressure in the fuel pump rises and at some point the safety valve of the venting excess pressure will work and the the fuel pump would cease to hold the pressure burdening it.

Consequences - a bad start and a permanent failure of the pressure in the fuel line.
Low fuel level in the tank.
To ensure proper operation, the electric fuel pump must always be submerged in fuel - to ensure its cooling, and, to some extent, the grease.

Consequences - when there’s little fuel left in the tank and the fuel pump during motion at some point will run dry, because of the movement of fuel in the tank, the fuel pump overheats bad, and the engine windings eventually fail.

The water content in the fuel.
The fuel may contain water. The water, getting to the fuel system from the fuel tank during engine operation, the water remains there and after even after the car is turned off. At low temperatures, when the engine is cooled off, water simply freezes and expands at the same elements capable of mechanically damaging the fuel pump.

The recommendations of the car manufacturer include the deadlines for replacing the fuel filters, both by mileage and time. Therefore, if a scheduled car maintenance requires replacement of the fuel filter, it is recommended not to ignore the replacement. They must be changed!

The fuel level indicator shows the approximate amount of fuel in the tank. It is necessary to promptly fill the fuel tank and monitor that the amount of fuel in the tank never drops below a quarter of the total capacity of the tank. If the indicator lights up a minimum level of fuel in the tank or is near the “E” mark (Empty), refill your tank immediately.

Fuel filter

Fuel filter – is a fuel system component which is required for filtering and neutralizing rusty particles or dirt contained in metal containers for storage and transportation of fuel and contaminants in the fuel and water, which are formed on the surface of the fuel tank.
During the reaction of fuel with air or metal, various chemical compounds generate dust and dirt in the fuel tank.

Consequences. The accumulation of tar deposits also negatively affects the car’s power system. These and other factors are causing fuel filters to be non-operational, requiring subsequent replacement.

The deadline to replace the fuel filter is specified by the manufacturer on the package, and is usually about 15-20,000 kilometers for petrol and up to 60,000 km for diesel engines. Meanwhile, experts recommend a comprehensive approach in determining the replacement timing: to take into account operating conditions, the vehicle manufacturer's recommendation, the quality of fuel. Depending on these parameters the deadline may be shortened.
An indicator to replacement of the fuel filter would be the reduction in power or unstable operation of the engine, difficult start of the engine and increased fuel consumption.

Fuel pressure regulator

Fuel pressure regulator - is one of many of vehicle units, which regulate the fuel pressure. This is a membrane valve, on the one side of the membrane there is the pressure of the fuel; on the other side – there is the spring intake collector, once the engine goes loose from the load, the valve opens and the fuel is supplied back to the tank, i.e. the regulator creates a constant fuel pressure.

Causes and Consequences
Over time, the spring in the regulator may loosen and not be able to create the necessary efforts, as a result the fuel will rush back to the tank, thereby decrease the pressure in the fuel rail. As a result, there would be a shortage of fuel and the loss of power in the engine.

Also a valve shimming may occur, in which case the pressure in the fuel frame will not change regularly, so that there may be an unstable operation of the engine, including jerking when accelerating.

When these causes and failures occur and are identified in the regulator it is recommended to repair the unit or replace it completely.

Injector is intended for the fuel supply dosage, spraying it into the combustion chamber (intake collector) and the formation of the fuel-air mixture.
Injector is used in the injection systems in both petrol and diesel engines. In modern engines injectors are installed with electronic fuel injection control system.

During the operation of the engine, the elements of its fuel system - injectors (nozzles) are gradually getting clogged by the residue in the fuel, any fuel contains residue regardless of its quality.

Within a few minutes after the engine stops and while it is hot, the spray gun nozzle collects residue. The light fractions of fuel evaporate, and the heavy ones form a layer of solid deposits that will eventually increase to such an extent that they would impair the working process, and eventually incapacitate the injectors (nozzles). The deposits on the injectors are black and brown lacquer peel and slag, which are difficult to clean and do not dissolve in gasoline.

Signs of contaminated injectors that could be on all models of vehicles with injector:
- Unstable idling: the engine "misfires";
- Difficult start of the engine: the engine starts with the second - the third attempt, it is difficult to stabilize idling speed;
- Empty space when pressing the accelerator pedal, the driving feels uncomfortable;
- Deterioration of the vehicle acceleration and loss of power: a car with automatic transmission pulls the lower transmission speeds up sluggishly, popping in the exhaust system can be heard;
- Misfires of fuel mixture: jerking when accelerating, error codes for the loss of sparking (misfire) may be felt, accompanied by the failure of the spark plugs, electrical wires, ignition coils;
- Constantly increasing fuel consumption: as contamination of injectors is a gradual process, the driver usually notices this later.

The injectors in engines of known manufacturers are very reliable and durable. They are designed virtually for the entire period of reasonable operation of the vehicle at 200-300,000 km.
The procedure for cleaning the injectors is recommended every 20-25,000 km. However, to restore the normal operation of the injector it is recommended to completely replace the defective part.

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