Volkswagen Touran engine fault light lit

A mileage only 4600km, equipped car diagnosis tool shop with a 1.4L TSI direct injection engine, 5-speed manual transmission, 12-year Shanghai Volkswagen New Touran car. Reflects the owner the car engine failure in the process of moving lights lit.
Pick-up: First Volkswagen diagnostic instruments VAS 5051B vehicle engine control unit checks, there is fault code 00369 "fuel adjustment cylinder column 1 system too lean", the meaning of the failure code for a combustible mixture of gasoline and the operation of the engine work too thin. Input channel number 032, reads the data of the engine ECU on the adjustment of the combustible mixture of steam, and the display data is not within the normal range, and a large deviation (Figure 1).

Clear fault Car OBD2 Tools supplier  codes, the 32 sets of data automatically zero. Start the engine, the engine idle speed to low and operation jitter serious. Why clear fault codes, engine idling normal? The reason is clear fault codes, engine ECU fuel injection quantity correction, the value of learning and memory to zero, in accordance with the standard data injection. The mixed steam too dilute fault still exists, the engine idling is very unstable, and also shows the engine combustible mixed vapor partial thin indeed, the status of the combustible mixture of gasoline and oxygen sensor information passed to the engine ECU true expression, therefore, you can exclude the the possibility of failure of the oxygen sensor.

VAS 5051B to Auto Diagnostic Tool connect the road test, while observing the engine data stream gradually increased (Figure 2), 32 group 2 data load mixed steam parameters, test driving about 10km, engine malfunction light up again, failure code remains the same. The engine idle longer jitter.

After a comprehensive analysis of the above checks, resulting in: (1) low fuel pressure, caused by the fuel injection less engine hybrid vehicles in the process of moving steam too lean; ② fuel quality standards, add various stabilizers, anti-deflagration agent over more, resulting in the ECU in accordance with the amount of air entering the cylinder is injected into the corresponding component of the fuel, but there is a certain percentage of the material does not participate in the combustion, for example, 5 percent of other substances that do not participate in the combustion, the oxygen content of the exhaust gas is high, the engine ECU through the oxygen sensor detection value is still too dilute to determine the mixed steam; ③ injector clogging.

Based on the above OBD2 diagnostic tools analysis, inspect and repair the vehicle again, the first to use the low-pressure line pressure of the fuel pressure gauge measuring fuel supply system. Operation of the engine, the fuel low pressure the 0.65MPa (Figure 3), the engine stall maintain 10min after the low-pressure fuel pressure of 0.47MPa, the normal (Figure 4).