A Guangzhou Honda accord 2 L car with a mileage of over 230 thousand km in 2003. User response: when the speed exceeds 70 km/h, the engine will speed up bad, work jitter, and the engine trouble lights occasionally shine; when the car speed down to less than 70 km/h, the engine work will become stable again. After receiving the car: the first test run, confirm the fault phenomenon, found that there is indeed the above fault. According to the test conditions and judging by vehicle conditions, the common causes of bad acceleration and engine jitter may have the following aspects: one is the oil system fault, such as the blockage and leakage of the injector, the insufficient oil supply pressure or the oil pressure, the gasoline filter dirty, the gasoline pump screen dirty plugging, the gasoline pump serious wear and tear, the fuel pipeline The two is the breakdown of the circuit system, such as the breakdown of the circuit system, such as the aging of the high voltage line, the serious ablative spark plug, the low ignition voltage, and the three is the mechanical fault, such as the serious wear of the individual cylinder, the loosening of the engine support and the fixed bolt, and the four is the air system fault, such as the air filter, the air flow sensor, the intake air. Manifold, absolute pressure sensor, idle speed control valve or throttle position sensor and other faults, the three way catalytic converter seriously obstructed exhaust and so on. Based on the above analysis, the following inspections were carried out in accordance with the principle of "ease first and then harder." First check the oil road. The filter screen of the gasoline filter has been replaced with a new one; check the fuel line without leakage. Then check the relevant circuit and the mechanical part, check the spark plug, a small amount of carbon, clear the carbon after the fire test, normal; change the one cylinder of a cracked cylinder line after the fire, normal; check engine support, fixed bolts and so on no loosening phenomenon. No obvious abnormalities were detected in the gas path system. Connect the fault detector, read the fault code for the 07-01---- throttle position (TP) sensor voltage is too low, according to the fault code prompt, successively cleaning the throttle body and the injector. After matching test, it is found that the car has good performance at low speed, and when the speed rises to 70 km/h, it feels the engine speed. And slow speed increase; check the line of TP sensor, normal. At this point, it is basically determined that the fault is caused by the TP sensor itself. Troubleshooting: throttle position sensor has been replaced.