Symptom: the car recently the car out of the accident, but the original car to repair the ignition coil to lose, for a new deputy factory ignition coil. After the change is found there is no high voltage fuel injection, after inspection found that the ignition coil failure. For the factory is qualified accessories, to smooth the car, but the black smoke idle jitter.
    Maintenance of the first connection Jinde K81, read the data stream, fuel injection rate of 3.8ms, water temperature of 90 ° C, throttle angle of 8 °, inlet pressure of 380mbar (about 38kPa), idle when the oxygen sensor voltage 0.8 ~ 0.9V, 2500r / min in 0 ~ 0.9V fluctuations, are within the normal range. And then connect the K81 oscilloscope to see a cylinder fuel injection waveform is normal, is preparing to see two cylinder fuel injection waveform, found a strange phenomenon. When the two-cylinder nozzle plug unplugged, and found that the engine jitter but to reduce the exhaust pipe is no longer black smoke! With the oscilloscope to see the two-cylinder fuel injector waveform, found that the waveform is not normal, the maximum voltage is only 20V, under normal circumstances should be able to reach more than 60V. Check the two-cylinder fuel injection signal to find the computer board pin line normal. So remove the engine computer later opened and found in the one, two, three, four cylinder fuel injection driver feet next to a chip capacitor, but the two cylinder pin next to the patch capacitor color black, for a model Chip capacitors after the car, all normal, speed up, no longer jitter idle, do not smoke, troubleshooting.
    Fault Summary: After careful repair car repair why the two-cylinder chip capacitors will be damaged, check the "fuel injection, no ignition" phenomenon. With a common test light detection, so use the test light to check the fuel injection drive line, the computer's capacitor damage is not difficult to explain.
    Through the maintenance of this car feel, now there is no good car repair equipment is not enough. Decoder computer data analysis and oscilloscope scan area at the same time and comprehensive analysis, in order to find the cause of the malfunction.