"EFI car" high score consultation

1: EFI vehicle refers to a vehicle equipped with an electronically controlled fuel injection system.

The electronically controlled fuel injection system is controlled by the micro-integrated circuit according to various working conditions of the automobile and the engine, which promotes the complete combustion of the fuel in the engine, thus greatly reducing the exhaust pollution. Generally speaking, compared with carburetor truck, EFI truck has the advantages of high power, fuel saving, low noise and high primary ignition rate. Therefore, EFI car is the first choice for economy, practicality and environmental protection.

There are great differences between EFI engine and carburetor engine, and their operation methods are also very different. When EFI engine starts (including cold start), it is generally unnecessary to step on the accelerator. Because the EFI engine has the functions of cold start and enrichment, automatic cold start and fast idle, the engine can be started smoothly whether it is cold or hot. Before and during the engine start-up, it is ineffective to repeatedly and quickly step on the accelerator pedal to increase the fuel injection amount like starting a carburetor engine. Because the accelerator pedal only controls the throttle opening, the fuel injection quantity of EFI engine is completely determined by the computer according to the intake parameters. When the fuel tank is short of oil, the EFI engine should not run for a long time. Because the electric gasoline pump is cooled by the fuel flowing through the gasoline pump. Running the engine for a long time without oil in the fuel tank will cause the electric gasoline pump to burn out due to overheating, so if your car is an EFI car, you should refuel as soon as possible with the fuel warning light on the dashboard. Do not unplug any sensor plug when the engine is running, otherwise there will be artificial fault codes in the computer, which will affect the correct judgment and troubleshooting of maintenance personnel.

Not all the new cars produced now are EFI cars.

2. Guangzhou Honda 08 Sidi and Fit Sport will announce the price the day after tomorrow, and they experienced 08 Sidi for the first time in Guangzhou University Town. Although it is not brand-new, it has created a mature charm after comprehensive and meticulous improvement.

You should know it after reading the explanation of the EFI car. )

3. When the EFI engine is working, it needs to obtain data from various sensors at any time, and then it is calculated by the driving computer and sent to the executive part for adjustment to realize the control of the engine. Simply put, it can be divided into the following situations: (only for EFI engines)

① Stop: When you turn the key to the on position, the driving computer starts to self-check the sensors and actuators, and at the same time, turns on the relay of the gasoline pump to supply oil. At this time, if the car is quiet, you will hear the sound of the electronic oil pump turning in the fuel tank. After about 1-2 seconds, when the oil pressure reaches the standard pressure, the gasoline pump stops running. At the same time, the computer will supply power to the idling stepping motor at the throttle to make it enter the normal position. At this time, turn the key to the starting position, turn on the starting relay, and the starter starts to rotate;

② Idle speed: After the starter starts to rotate, the computer begins to read the readings of the crankshaft position sensor located on the flywheel of the engine and the synchronous sensor located on the distributor. If the readings are normal and the changes of the two signal data are consistent with the starting conditions, the computer will adjust the idle stepper motor and adjust the idle adjusting lever to a proper position according to the current engine cooling water temperature and intake manifold air temperature data. After everything is ready, the computer starts to calculate the ignition timing according to the signals of the crankshaft position sensor and the synchronous sensor, and calculates the opening time slot (pulse) of the oil nozzle according to the data of the water temperature sensor and the air temperature sensor, and then starts to supply power to the low voltage line and the oil nozzle line of the high voltage package according to the calculation results, wherein the power supply to the oil nozzle is carried out by pulse. According to the above principle, it is not necessary to start the EFI vehicle in freezing weather, otherwise the driving computer will calculate the opening data of solar terms, which will affect the starting effect. After the ignition is successful, the driving computer will monitor the data of each sensor at all times, and adjust the starting pulse of the idle motor and the fuel injector according to the vacuum pressure value transmitted by the absolute pressure sensor of the intake manifold installed on the engine, combined with the signals such as water temperature and intake temperature, so as to control the speed at the lowest stable speed;

③ Acceleration: when stepping on the accelerator, the computer reads the value from the accelerator position sensor on the accelerator in time, and calculates the vehicle load information by combining the absolute pressure (vacuum degree) sensor of the intake manifold on the accelerator and the traveling speed sensor * * on the transfer case (202 1 Cherokee), and adjusts the fuel injection pulse of the fuel injector (in fact, prolongs the fuel injection time) to increase the fuel injection quantity to complete the acceleration action;

(4) Deceleration: When you release the throttle, the computer will adjust the fuel injection pulse to achieve deceleration according to the signals of various sensors, but at this time, in order to ensure a smooth deceleration effect, the computer will control the fuel injection quantity and will not reduce it to a very low level. When you release the accelerator and press the brake pedal again, the computer will get a signal from the brake switch under the brake pedal. In this case, the computer will stop the fuel injector to produce the best engine braking effect, and at this time, the computer will adjust the idle motor to a suitable position to ensure that fuel injection will start when the engine speed is low to a suitable position to ensure that the engine will not stall.

4. Engine oil has the functions of cooling, lubricating, cleaning and sealing, and plays a vital role in ensuring the normal operation of the engine. With the increase of engine working time, engine oil is polluted due to high temperature oxidation, wear of mechanical parts, fuel vapor corrosion and other factors. In addition, there is a certain consumption of engine oil in normal use.

Daily detection of engine oil is very important for engine maintenance and life. But how to check the oil level correctly?

Oil level check

In fact, you can have a simple physical examination before driving every day. First of all, make sure the vehicle stops on a flat road to improve the accuracy of oil level detection. If you stop on a rough road or a ramp, move the vehicle to a flat road, then turn off the engine and wait for about 5- 10 minutes, so that part of the engine oil staying at the upper part has enough time to flow into the oil pan. Then, take out the dipstick, wipe it with clean cotton cloth, re-insert the dipstick into the hole of the engine dipstick, and wait for a few seconds for the oil to completely adhere to the dipstick. Finally, take out the dipstick and observe whether the position of the highest oil mark on the dipstick is within the specified range. Each model has its own position calibration standard, so take Shanghai Volkswagen Passat as an example. There is a "pockmarked area" on the dipstick of this model, and the trace beyond the "pockmarked area" on the dipstick indicates that there is too much oil, so it is necessary to drain some oil until it reaches the specified position. On the other hand, if the "hemp zone" cannot be reached, it is necessary to change the oil to avoid too little oil, so that the engine can not be properly protected.

Oil quality inspection

After checking the oil level, finally check the oil quality. The method is also very simple. First, observe its transparency. If the color is transparent and slightly polluted, it means it can still be used. If the color is black and smells sour, it is necessary to change the oil at this time, because the oil has deteriorated and cannot play a protective role. Then check its viscosity, stick a little oil on your hand, and check whether the oil is still stuck with two fingers. If the fingers are not sticky, it means that the oil has reached the limit of use and needs to be replaced to ensure the normal operation of the engine.

Matters needing attention

If you find that the engine oil is insufficient, you must not ignore it. Driving without oil for a long time will cause the engine to "pull the cylinder" and drag it to the repair shop for engine overhaul. The lighter one only needs to replace a part of the parts, and the heavier one will replace the engine assembly, which is extremely harmful. But you can't blindly add oil to the engine yourself. It is wrong to inject new engine oil without draining the old engine oil. The correct way is to drain the oil and replace it with a new oil filter. Because the impurities in the engine oil are filtered through the engine oil filter, if they are not replaced, the impurities left on the filter will flow into clean engine oil, and the oil quality will be polluted, thus losing the significance of replacement. Therefore, when changing the oil, the oil filter should also be replaced. Then pour in new engine oil until it reaches the designated "pitting area".

In addition to the above methods, some models will have warning lights to remind you that it is time to change the oil. For example, Shanghai Volkswagen Passat has two oil level warning lights. When the yellow light comes on, you should be ready to change the oil. If the oil level has reached the limit when the red light is on, you need to stop the engine immediately to avoid unnecessary damage to the engine and wait for the rescue of the trailer.

Regular maintenance and maintenance

Perform oil maintenance every 5000-7500 kilometers (refer to the kilometers specified in the maintenance manual for specific models). If the mileage does not exceed 5000-7500 km within 3 months, the oil should also be changed.

Proper daily inspection and maintenance of engine oil can prolong the service life of the engine, ensure its dynamic performance and keep your car "heart" youthful forever.