The user drives for a long time. When the air conditioner switch is pressed when the speed is idling, the air conditioner compressor clutch is frequently sucked more than 4 times to work normally. When the accelerator pedal is pressed and the engine speed rises to 120 rpm / m in , the air conditioner compressor clutch is normally closed, and the acceleration in the second gear is hysteresis. The vacuum manifold is used to detect the intake manifold pressure reflected by the air pressure sensor vacuum tube. The idle speed is about 60 kPa, which is within the standard range. Connect the cylinder pressure gauge, test the engine cylinder pressure, and find that the cylinder pressure of each cylinder is lower than the standard value. It seems that the piston ring or valve sealing of the engine is poor.

This car has a very slow starting speed when the engine is accelerating. And it is difficult to add to high speed. According to the driver's report, the car was slow to speed up and came to our factory for testing. At that time, no faults were detected, because the driver was eager to use the car and temporarily drove the car away. However, the problem was serious and had to be returned to the factory for repair. According to the fault phenomenon, first read which part of the fault occurred, and did the following tests: First, the engine idle speed is running smoothly, no abnormal noise, the air intake system has no air leakage, no obstruction, and the exhaust air is not blocked. Moreover, the exhaust gas reaches the standard, thereby detecting that there is no problem with the most basic components of the engine; second, the entire fuel system is inspected and tested.

First replace the petrol grid and test the fuel pressure. Unplug the vacuum tube on the oil pressure regulator and measure the oil pressure. The injector was cleaned and inspected, the entire fuel system was simply checked, and no problems were found. Third, the ignition system was checked. The first and second waveforms of the ignition are measured by an oscilloscope, and all conform to the standard. Since the ignition waveform is normal, it is sure that the entire ignition system is normal. None of the above three tests found any problems. Although the electronic control system does not find the fault code, the electronic control system cannot be without problems.