What are the phenomena of fuel system damage and how can I tell it?
Insufficient oil pressure makes the engine not work
The gasoline pump hidden in the fuel tank is to reduce the generation of gas resistance and the ingress of moisture, and there is a filter at the inlet of the gasoline pump, which has a thin diameter and can filter small particles of gasoline impurities. After the car is used for a long time, this filter will be blocked, which will cause the engine to fail to work after stalling, the solution is to release the oil pressure, clean the filter and re-add the improved gasoline or diesel.
The oil pressure regulator is installed at the end of the fuel delivery line and is used to regulate the pressure entering the injector, which is kept at a constant value of 300-350KPa and does not affect the vacuum of the intake line and the pressure of the gasoline pump. There is also a filter screen on the oil pressure regulator, if this filter is blocked, it will cause the sound of "through" air flow from the position of the vehicle fuel tank, and the fault can be eliminated by cleaning the filter screen with a special cleaning agent and then using compressed air to dry.
We can also remove the injectors and rails of all cylinders, check whether there is a large amount of carbon deposits and gasoline impurities in the installation position, and if so, it also means that the filter screen of the oil pressure regulator is blocked.
Moisture in gasoline can corrode fuel system components
Gasoline will contain some moisture, which may be generated during the production and refining process, or it may be that outside air enters the pipeline. In warmer temperatures, gasoline can properly dissolve some of the water, but in the cold state, the solubility of water in gasoline becomes poor, and the excess water will slowly accumulate at the joints of the filter and the tubing, and the amount of oil supplied to the pipeline will be intermittent.
The components in the fuel system have been corroded and damaged by water for a long time, and it is best to replace the relevant components in the fuel system, use gasoline to flush the oil circuit and oil pipe, and remove the water in the fuel line before the engine can resume work.
Injector leaks cause the mixture to be too thick
There is a seal on the injector, if this seal leaks it will cause the injector to leak, we can see that there are a lot of oil stains next to the intake manifold. The main reasons are low fuel pressure (e.g. 160-180KPa at idling) and exhaust gas tests show high levels of HC hydrocarbons and CO monoxide.
During the inspection, focus on checking the coolant temperature sensor and air flow meter that have the greatest impact, and check the coolant temperature under the corresponding vehicle conditions, such as 80-90 degrees Celsius related to the hot car state, which will certainly not be as low as 20-30 degrees; the air intake detected by the air flow meter at idle speed is 30Hz, and the engine speed can be increased to 50-60Hz.
