Symptom: A Honda Accord, using MPI (multi-point jet) 4-cylinder engine, A / T (automatic transmission). This car starts when the slow delay, shift late
    Troubleshooting: According to the owner, the car encountered in the city when the signal lights, and then start a particularly slow, other cars have been Chi Chi away, and this car is still in place; and the owner reflects the car in less than 60km / H driving, the acceleration is not smooth, feeling obvious nausea; and all high-speed normal. The car sent to my factory, ready to use easy to pass the decoder to detect it, but found that the car's inspection joints were cut off, they can not be detected. So the maintenance staff decided to use empirical methods to check and judge. Carry out road test, do routine inspection and judgment. First shift the shift lever from the P file to the D4, release the brakes, do not step on the throttle, the car can move forward, indicating that the transmission transmission D4 file one-way clutch without failure. When the shift to the D3,2,1 file, the car can also move forward; This shows the transmission in the guide wheel is also normal, no slippery, in the low speed to pass power. Then the transmission is not a fault, the fault should be on the engine. Continue to check, when the pedal accelerator pedal speed rose to 60km / h, the engine speedometer pointer stopped at 1700rpm does not move, about 30 seconds to rise. When the speed rose to 1800rpm, only shift feel; this shows that the acceleration is not smooth, slow shift. And when the speed is higher than 60km / h, the acceleration of all normal. According to past experience to judge, this failure for the engine power shortage.
    Usually the engine power is insufficient, you should first check the high voltage circuit. Back to the repair shop, when the ignition switch to the ON engine failure instructed to light up for 3-5 seconds, start the car, fault indicator light is not lit, that PCM is not self-test to the fault; Find two-pin plug short-circuit code, there is no fault code generated. Basically, the engine fuel and ignition system is not much trouble. First do some routine checks. Look at the high pressure fire strong, when the high damping line unplugged, from the cylinder 6-8mm flashover, playing a cylinder spark is very weak. In order to ensure that the ignition system can work properly, the spark plug inspection, the spark plug from the car to remove the inspection, see a group of spark plugs after the re-installation, the road to the road, in order to ensure that the ignition system to work properly, Test, found that the performance of the car has improved, but the feeling of the car or some boring, shift late, proving the engine power shortage. The circuit has been resolved without problems, the failure may be in the oil.
    In the engine idling, the measured oil pressure is 12PSI, belongs to the normal value, when the engine speed increases, the oil pressure also rises steadily. Fuel pump work properly, when the injector removed from the car and found that the injector is very dirty, with carburetor cleaning agent clean, and measured with a multimeter, the resistance value of 3.1 ohms, the resistance is normal. At the same time field experiments, to the injector power, observe the size of the spray oil mist. See the fuel spray after the sprayer fog closer to the ideal state to prove that the injector back to normal work. The fuel injector loaded back to the car, from the road test, the engine speed continued to rise, and 1750rpm near the smooth shift. That is low speed, smooth and smooth. Feeling the car is particularly powerful, high speed is also normal. This troubleshooting is complete. This car due to high-pressure sub-cylinder line leakage, resulting in insufficient ignition energy; and because of the long-term poor fuel injectors lead to dirt, resulting in accelerated fuel injection is not enough, causing mixed gas dilute, a comprehensive cause of engine power shortage. As the engine power is insufficient, the speed increases slowly, a short time can not reach the specified speed, PCM (power control module) does not give the shift, so feel the shift late, but also because the engine power shortage, throttle step, A little difference, so the performance is not easy to accelerate. Resulting in poor speed at low speed. In the case of road red light, the car started slowly.