Fault Diagnosis Research Of The Electronic Fuel Injection System

With the rapid development of microelectronics, computer and control technique, it has been a new tendency in the automobile electronic technique to utilize electronic control techniques to raise engine performance, reduce energy consumption and meet the increasingly strict emission regulations. However, almost none of the home automobile manufactures has the intellectual property right about the electronic fuel injection (EFI) system at present. The home automobile manufactures depend on importing foreign product line of EFI system or the foreign electronic control unit (ECU) directly supplied by the foreign manufacturers. In order to alter the actuality, it is very important to develop the EFI system independently. Automobile malfunction diagnostic technology, which is an important part of the automobile electronic control technology, plays an important role in the maintenance work. The paper has deeply discussed the fault diagnostic system about the EFI system.The paper introduced the status in quo and development tendency about the automobile fault diagnostic system, and discussed the On-Board Diagnostic (OBD-II) system concretely, designed the fault diagnostic system based on the Keyword Protocol 2000(KWP2000), and discussed the system's communication software and interface circuit. The communication module as the bridge between diagnostic system and ECU, achieved the communication between ECU and PC, transmitted the processed data at the real time.Furthermore, The paper discussed the hardware and software of test instrument of engine ignition fault based on 89C52. Take the familiar Hall electronic ignition system for instance, introduced the sampling and processing course about its ignition signal. The test Instrument of engine ignition fault can measure and display the dwell angles and ignition distant angles about engines of discretional cylinder numbers, and the anti-jamming design of filter about signal-sampling is well. The show values which can incarnate the capability of ignition system well and truly are important quality parameters of distributor and igniter of engine. The instrument makes sense to the adjustment of ignition timing and the ignition ahead angle.