Symptom: South Korea Hyundai Sonata accelerated bad.
    Troubleshooting: This car is older. See the control of the engine to use more vacuum control, we know that the car is the introduction of Japanese technology production. Start the engine and found that the car's idle very unstable, try to step on the accelerator pedal, the feeling of the engine is not a little power, and the emergence of loose speed pedal, to turn off the feeling of accelerating the pedal step faster feel more Ta Kong.
    After a preliminary inspection, you can determine the car road problems, resulting in stepping off the accelerator pedal when the engine to turn off. Then connected to the oil pressure gauge, measured the car's oil pressure, the measured data is idle only 200kPa. Acceleration is only a little more than 200kPa. This shows that the system oil pressure is low, causing the system oil pressure is mainly due to oil pressure regulator and fuel pump. Remove the oil pressure regulator carefully check, although some dirty but all the parts are good, it seems that the oil pressure regulator is not a problem. And then remove the fuel pump, measured resistance found resistance is too large, power test its pump capacity is also weak. It seems gasoline pump has been aging, performance deterioration. Replace the petrol pump, and then measure the oil pressure at this time greatly improve the system, at idle speed to 280kPa, when the oil pressure reached 320kPa, the fuel system completely back to normal.
    To solve the main problem, but the engine at idle, there is still between 1000 ~ 1400r / min tour phenomenon. Began to think that the vacuum tube has a leaky place, check the vacuum tube does have broken, after the replacement, or the car. And carefully observe the car's idling control valve ISC, the harness plug damage is serious, so plug in the ISC valve is very loose, is not it the reason? Deal with the plug, re-match the idle control valve, this time this car is not And then travel, but the idle speed is still 1200r / min, high. It is not a wave of ups and downs.
    And observed the various sensors, see this car's TPS throttle position sensor is similar to the Toyota Crown car on the manual adjustable, look at the TPS initial fastening position seems not accurate, and that two fastening screws The original car, and the other is equipped with a hand breaking off a TPS, found that it is only one of the screws in the work, can be a small range of mobile, which is certainly not, it seems that the reasons for high idle The. General EPC TPS in the idle position when the voltage signal value between 0.3 ~ 0.8V, with a multimeter to measure the TPS in the idle when the correct initial position, fastening
    After driving out of the test, the accelerator pedal response quickly, accelerate the powerful, the car is easy on the 140km / h, the fault completely ruled out.