gasoline vehicle exhaust pollution test methods
At present, China’s car exhaust pollution test methods can be divided into the idle speed and idle speed, steady-state driving mode conditions, transient operating conditions method and simple transient condition method. GB18285 – 2005 provides that: since the date of the standard, the national ignition engine vehicle emissions monitoring requirements of this standard two-speed idle exhaust pollutant limits and measurement methods; large vehicle fleet, severely polluted areas, but also can be steady-state conditions, transient operating conditions and simple transient conditions France three kinds of BASM in a way as in the detection method for exhaust pollutants from vehicles. The BASM areas, local exhaust emission limits should be established.

1, at idle speed

At idle speed the car is stationary, the engine is idling condition, with no load, turn off air conditioning and power steering pumps, and sampling the exhaust pipe into the car exhaust pipe ending in accordance with specifications in the automotive exhaust CO and HC concentration detection.

Idle detection is characterized by the empty load can only reflect the state of engine idling emissions when the engine is poor oxygen partial thick burning CO and HC, resulting in little or does not produce NOx, idle detection is convenient, and testing equipment prices and The use of low cost. Idle when the concentration of CO and HC emissions, while high, but the car idle running time of the proportion of the total running time, the test results is the lack of comprehensiveness, to improve the measurement accuracy, the country has begun a two-speed idle emissions measurement.

(1) speed idle test conditions.
Measurement, so that the car is in idle condition. Idling condition refers to the engine without load operation, namely the clutch in a joint position, the transmission is in neutral position (for automatic transmission car in “park” or gear carburetor fuel supply system of the car, the choke should be in full open position, the accelerator pedal is fully unlocked position until the engine to achieve the required thermal state, then specified by the manufacturer to adjust engine speed is raised to the provisions of the idle speed and ignition timing in the exhaust the case of system leaks, exhaust analyzer measurements.

(2) speed idle test procedure.
1) engine from idle to rise to 0.7 times the rated speed to maintain the 60s, then fell to the idle state.
2) the engine in the idle state to maintain 15s, began reading, reading the 30s within the minimum value and maximum value, its average value is the measurement results.
3) If more than the exhaust pipe, whichever is the arithmetic mean of each exhaust pipe to measure the results as the measurement results.
2. Two-speed idle

The two-speed idle conditions the concentration of the test vehicle emissions in the idle condition and Gao idle. High idling condition that meets the conditions of the idling engine speed with the accelerator pedal stability control Gao idle speed when the conditions prescribed in 50% of rated speed or manufacturer technical documents. The high idle speed of the light vehicle provisions the provisions of the 2500 ± 100r/min, heavy-duty trucks idle speed of 1800 ± 100r/min; if there are special provisions should be in accordance with the manufacturer technical documentation specified high idle speed.
 
Two-speed idle test procedure:

1) shall ensure that the normal state of being detected vehicle is specified by the manufacturer, the engine intake air filter, exhaust system shall be equipped with exhaust muffler, and shall not leak.
 
(2) shall be installed on the engine tachometer, ignition timing device, coolant and lubricants thermometer measuring instruments. Measurements, the engine coolant and oil temperature should be not less than 80 ° C or automotive provisions of the Manual hot car status.
 
(3) engine to accelerate from idle to 70% of rated speed down to Gao idle state after running 30s. Insert the sampling probe into the exhaust pipe, depth of not less than 400mm, and fixed in the exhaust pipe. Maintain the 15s, 30s within the average read by the average functionality of the instrument or manual read the highest and lowest values ??in the 30s, the average is high idle pollutant measurements. For closed-loop control of electronic fuel injection systems and catalytic converters to control car, but also read the value of the excess air ratio (λ).
 
(4) from Gao, the engine idle speed dropped to idle 15s, 30s within the average read by the average functionality of the instrument, or manually read the highest and lowest values ??in the 30s, the average is idling pollutants measurement results.
 
(5) for more than the exhaust pipe, take the exhaust pipe of the arithmetic mean of the measurement results as the measurements.
 
(6) If the vehicle exhaust pipe length is less than the measured depth should be used when the exhaust extension tube.
 

3. Steady-state conditions method

The steady-state conditions (ASM) refers to the car warm-up to the required thermal state, accelerated to the required speed, acceleration load in the speed of the car provisions, through the chassis dynamometer car load, making the car to maintain constant speed operation operating conditions, the situation in this condition to test vehicle exhaust pollutants.
 
ASM test operation cycle is composed of the ASM5025 ASM2540 two steady-state conditions, shown in Figure 4-6.
 
(1) the ASM5025 working conditions. Dynamometer vehicle acceleration after warm-up to 25.0km / h, the vehicle speed is 25.0km / h.
 Acceleration of 1.475m / s for 50% of the output power as the power of setting the vehicle load conditions the counter starts
 (T = 0). Continue to operate the vehicle (25.0 ± 1.5) km / h speed 5s chassis dynamometer simulation is used to measure the timing open
 The beginning of sustained 3s than the prescribed error range, the operating mode the timer will re-start time (t = 0). If the recurrence of the situation,
 The test will be stopped. System will be preset according to the longest response time of analyzer (analyzer response time of 10s, then
 Preset time for the 10s, t = 15s), and then start sampling, continued to run 10s (t = 25s) is ASM5025 quick check
 Conditions. The ASM5025 quick check conditions continue to run until after the end of 90S (t = 90s) is ASM5025 conditions.
 
(2) ASM2540 conditions. Set the the ASM5025 conditions to detect the end of the vehicle immediately accelerated to 40km / h, the dynamometer vehicle speed is 40.0km / h, acceleration is 1.475m1 / s 2, the output power as a power load of the vehicle. The operating mode timer start time (t = 0). Vehicle (40 ± 1.5) km / h speed continued operation of 5s, if the chassis dynamometer to simulate the inertia values ??continued after the clock started 3s beyond the required range of error conditions timer will re-start time (t = 0) . If the recurrence of this situation, testing will be stopped. System will be preset according to the longest response time of the analyzer (if the analyzer response time of 10s, then the preset time is 10s, t = 15s), and then start sampling, continued to run 10s (t = 25s) is ASM2540 fast Check the working condition. The ASM2540 quick check conditions continue after the end run to the 90S (t = 90s) is the ASM2540 conditions.
 

4. Transient operating conditions method

The method of transient operating condition is the car running on a chassis dynamometer to the real operating conditions for the simulation of car, car engine discharged exhaust gas composition of the instantaneous concentration value measured in the loading case, the car can be a true reflection of the actual driving The emission characteristics. Transient loaded mode test cycle includes idle, acceleration, constant speed and deceleration of a variety of conditions, so than the idle and ASM method complex. Transient operating conditions of exhaust pollutants measured values ??in g / km.

This emission test system is not only bulky and expensive, thus limiting its widespread use. So far, the car driving emission standards developed by the countries under transient operating conditions France only as stereotypes vehicle identification, research and production sampling purposes.

The basic configuration of the transient loaded mode emission test system in Figure 7. It preclude the use of test equipment chassis dynamometer, exhaust sampling system and exhaust analyzer.

The chassis dynamometer shall be equipped with power absorption devices and inertial flywheel of 〖or electric simulated inertia and resistance to the vehicle and the vehicle acceleration inertia \ to simulate the road. It should be equipped with double drum, drum diameter 200 ~ 530mm, applicable to the maximum total mass of not more than 3 500kg of light vehicles. Its maximum power to ensure that at 100km / h for the 56kW, the maximum safe test speed of 130km / h.

Exhaust sampling system uses a constant volume sampling (CVS), can be continuously measured and diluted with ambient air under controlled conditions for collecting the exhaust sample gas sampling probe is installed within the CVS system, the critical flow venturi ((the CFV) structure should ensure that the sample collected continuous volume of the device where the test site ambient temperature may be lower, requiring sampling tube for heating, the heating temperature is a minimum of 50 ° C, the most Gao 120 ° C during the test should be able to monitor the temperature.

Exhaust analysis system should be able to several pairs of HC, CO, CO2, NOx, exhaust pollutants automatic sampling points and record. The accuracy of the analytical instruments, precision, drift, the requirements of anti-interference and noise characteristics are consistent with the relevant provisions of the U.S. EPA4201-00-007 regulations. Total hydrocarbons (THC) were analyzed using the FID method, CO and CO2 analyzes were performed using the NDIR method, NOx, analysis of the CLD method.

Method compared with the steady-state conditions, transient operating conditions law is not only able to identify high emission vehicles, and be able to distinguish whether the vehicle is to get the right maintenance, and the charcoal canister evaporative emission control system functions to be checked.

5 Simple transient loaded mode

Simple transient conditions law is the latest development in the United States a car emissions test methods to overcome the shortcomings of the high cost of the transient operating condition method. This method is cost slightly Gao in the method of steady-state conditions, but lower than the transient loaded mode testing high precision.

Simple transient loaded mode still preclude the use of exactly the same operating conditions, transient operating conditions and transient conditions method using the same chassis dynamometer, and drawing on the transient operating conditions to measure the diluted exhaust will eventually come to the advantages of pollutant emissions quality, simple drawing of ASM can directly use a simple type exhaust gas analyzers can be on the pollutant concentration test characteristics, using a device known as the “gas flow analyzer to measure car exhaust flow 〖treated computing diluted, and ultimately also be obtained in the quality of vehicles for each pollutant emission. In the absence of the CVS exhaust gas analysis system, simple operation, equipment investment is reduced by 50%.

Simple transient conditions pollutant emissions test equipment, including the one least able to simulate the acceleration inertia and uniform load chassis dynamometer machine, sampling and analysis system consisting of a five-gas exhaust analyzer and a gas flow analyzer. It can be real-time analysis of the quality of emissions of exhaust pollutants from vehicles in the load conditions. Simple transient loaded mode exhaust pollutants measured value of the units is also indicated by.

The same simple transient conditions method and transient operating conditions of test conditions and the use of chassis dynamometer dynamometer. Five gas exhaust analyzer for analysis of CO, HC and CO2 NDIR method, were analyzed using an electrochemical method of NO.

The gas flow analyzer to the final testing of the quality of the discharge of pollutants. Its structure consists of a microprocessor, zirconium and oxygen sensors, blowers, ventilation, flow sensors, temperature and pressure sensors. Which the wrong oxygen sensor is used to test the dilution gas oxygen concentration changes in the testing process sensing devices, it also can measure the beginning of the test the ambient air oxygen concentration. Five gas exhaust analyzer oxygen concentration can also be used to calculate the dilution ratio. The flow sensor measured flow value is the actual flow of dilution gas, the flow value after correction of temperature and pressure compensation, you can get the standard flow of dilution gas.

Bian kind of system has two branches, a branch of the five gas exhaust analyzer sampling tube to extract a small amount of the original emissions gas sent to the five-gas exhaust analyzer, analysis of the original concentration of emissions of pollutants: Another branch of the gas flow analyzer air pump after inhalation of the exhaust pipe of the remaining exhaust gases with ambient air mixture diluted, sent to the gas flow analyzer, and by analyzing the exhaust gas flow.

In the data collection process, the system real-time measurement of emission gas concentration and dilution flow values ??gave calculation Wherever the pollutant mass emission values ??by computer calculations per second.

 regardless of light infrared gas analyzer.

Regardless of optical infrared gas analyzer is a from car exhaust pipes to collect gas samples, and concentrations of CO and HC contained in the continuous measurement instrument. It consists of the exhaust gas sampling device, composition of gas analysis equipment, the concentration of the indicating device and calibration devices.
 
A) exhaust gas sampling device. Exhaust gas sampling device consists of sampling head, filter, ducts, water separator and pump, as shown in Figure 3. Collected from the car exhaust pipe exhaust, filter and water separator to remove the carbon residue in the exhaust gas, dust and moisture into the gas analysis device through the sampling head, catheters and pumps.
 
2) gas analysis equipment. Gas analysis equipment were based on CO and HC in the exhaust gases absorb different wavelengths of infrared energy principles, respectively measure the concentration of CO and HC emissions of a variety of ingredients, mixed from the sampling device, and electrical signals in the form of transportation to concentration indicating device.
 
3) the concentration of indicator. Concentration indicating device composed by the indicating device of CO and HC indicating device. CO concentration in the volume fraction; the HC concentration of n-hexane equivalent volume of one million scores.
 
4) calibration device. The calibration device is an order to maintain the the instructions accuracy of the analyzer, so that it can accurately indicate the measuring device. Usually has a standard gas sample calibration device analyzer, the analyzer plant supplied for calibration standard gas samples, the standard gas sample injection port analyzer dedicated directly to the exhaust gas analysis equipment, and through the Comparison of the standard concentration value and indicated value of the calibration.

 
2   hydrogen flame ionization method

Hydrogen flame ionization method is the determination of the best way to exhaust contaminants only Xi, Gao’s sensitivity (up 10-9 magnitude, good linearity, fast dynamic response, and by the ambient temperature and atmospheric pressure The outside factor is small. not only can be used to stabilize the conditions tested, but also for transient operating conditions test.
 
FID working principle is based on organic hydrocarbons in the hydrogen flame combustion to produce a large number of ionization phenomena to determine the HC concentration. Due to the number of carbon atoms is proportional to the flame ionization degree with the introduction of hydrocarbon molecules, therefore the method for different types of hydrocarbon is not selective, and thus only the determination of the total.
 
Hydrogen flame ionization analyzer is usually by the burner, ion traps and measuring circuit. Shown in Figure 4-4 Figure FID works, the measured gas containing 40% H2 fuel gas mixture into the burner, with the introduction of air to form a combustible mixture. Ignited, ignition wire ^ (: will the hydrogen flame of high temperature 000 ° 2) cleavage of elemental carbon, and then the formation of carbon ions, the formation of ion flow in the external voltage 100 ~ 300V, the ion flow ( current〗 strength is proportional to the number of atoms and contraband, as long as the measured ion current size, you can get the HC concentration.

3, chemiluminescence

Analysis by chemiluminescence (CLD) of NOx in the exhaust is the best way. Preclude the use of CLD to measure to NOx their high sensitivity, the volume fraction of up to 10-7, response characteristics, the volume fraction in the range of 0 ~ 10-2 has a good linear output.
 
Chemiluminescence detection principle of the analyzer shown in Figure 4-5. Detection O2 continued into the ozone generator, ozone O3 into the reaction chamber. NO detection, vehicle exhaust via two-way valve directly into the reaction chamber of NO and O3 reactions produce chemiluminescence, through the filter into the photomultiplier, reflecting the concentration of NO signal by the amplifier output by indicating instruments , measurements of NO concentration. Detect wind O2, turn the two-way valve, automobile exhaust all through the catalytic converter, which NO2 into NO, and then into the reaction chamber and then reaction with O3, when measured by the instrument is the sum of NO and NO2 of NOx, , then the determination of the concentration of NOx and NO difference can be measured NO2 concentration. NO2 all converted to NO, catalytic converter temperature must be above 650 ° C. The purpose of using filters is separation of a given spectral region, in order to avoid some other chemiluminescence interference in the reaction gas.

4, the integrated analysis

Comprehensive analysis method is the use of automotive emissions analyzer while the C0, CO2, HC and NOx in method for the rapid detection of automobile exhaust. This detection method can not fully reflect the automotive pollutant emissions, engine bench or vehicle chassis dynamometer tests to meet the emission measurement requirements.

Automotive integrated emission analyzers, usually according to the requirements of vehicle emissions regulations, various exhaust gas composition analyzer unit synthesis with the testing equipment, and emissions regulations set forth in the gas emissions, it can analyze the measurements, the measurement using the NDIR method CO and CO2, FID method to measure HC, CLD method measurement of NOx.

Detection need to adapt to the electronically controlled fuel injection engine car, the modern development of the automobile exhaust analyzer to increase the O2 detection, measurement of O2 oxygen sensor that can detect five kinds of gases (CO, CO2, the HC, NOx, and O2), concentration of ingredients, and calculated exhaust CO, CO2,, HC, O2 concentration can be drawn from the values ??of the corresponding air-fuel ratio. Due to the complex structure of the CLD measurement equipment of the NOx concentration, with the five-gas analyzer without cld France, while the use of ndir measurement of NOx concentration, but its measurement accuracy is low.

 Anti-lock braking device of the exhaust method

 (1) recycling the exhaust brake anti-lock device:
 ① Turn off the ignition switch, pedal brake pedal repeatedly, lifted the pressure device.
 ② hydraulic braking system in accordance with ordinary methods exclude the exhaust air system. Exhaust order is generally: the right rear wheel – the left front – right front – left rear wheel. Finally, tighten the exhaust nest of eggs of mantis plugs, brake fluid filling required.
 Exhaust, turn the ignition switch, the use of diagnostic equipment to pump operation, release the exhaust plugs, brake fluid discharged until no air bubbles.

 (2) variable volume exhaust brake anti-lock device:
 ① The TECH-1 or T-100 scanner motor positioning the pressure regulator, so that one-way valve in the open position.
 ② in the pressure regulator at the front anti-gas plug then a transparent tube, and then exhaust the hydraulic system in accordance with ordinary methods of exhaust, brake fluid discharged until no air bubbles. Tighten the anti-gas plug, filling the required brake fluid.

 ABS system fault diagnosis and troubleshooting

2.1  Anti-lock braking unit (ABS) of the common symptoms and the main reason

 Modern car brake configured on four-channel anti-lock devices are generally controlled or three-channel sensor with four or three. Wheel speed sensor, electronic control unit ECU, electronic brake pressure regulator is controlled anti-lock device of the three major moving part.

 Anti-lock braking device common symptoms are: brake locking, brake failure, brake deviation, abnormal brake pedal, the brake is not unusual when the brake pressure regulator, after starting the engine brake warning lamp does not light and so on.

2.2   Anti-lock braking device common fault position

 ABS is the wheel speed sensors, electronic control unit ECU, brake pressure regulator and wiring harness connections between the three parts and other components.

2.3    Anti-lock braking equipment fault diagnosis and inspection methods

2.3.1  Preliminary examination

 (1) Check the battery voltage, capacity within the specified range, and check the positive and negative columns and wire connection is solid.
 (2) Check with the people 85 the fuse, the relay is intact, the plug is solid.
 (3) Check the parking brake is fully released.
 (4) Check the brake master cylinder surface Gao whether the required degree.
 (5) Check the electrical control system of the plug connector is loose or poor contact.
 (6) Check the system of ministries Ground is good.
 (7) Check the conventional braking system of work.
 If the fault can not be determined by the location of the initial inspection should be carried out other diagnostic and inspection.

 Related Links 6

 Read the 85 cars who hate it the meaning of the code, review and master fault code extraction and cleanup methods. Cars such as Toyota, Honda cars, VW and so on.

Steering System Troubleshooting

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 Car Steering System review the composition, structural features, working principle and Yu wheel positioning the role of each parameter, to know what’s what, that first established a steering system in terms of ideology normal working conditions, and exclusions for the steering system to determine the common hate to build it a comparison platform. It is also suitable for automotive fault diagnosis and exclusion of other faculties, that is, “there are more, only to identify.”

5.1   Steering system of the common symptoms and causes

 Steering system of common faults are: abnormal wear of steering wheels, steering wheel free travel is too large, heavy steering and the back is poor, put the front wheel made??, steering wheel and other thugs. Failure phenomenon is to identify the type of failure of the basis on which to judge and the first step in troubleshooting. Steering System Table 4-10 lists the common symptoms and causes.

5.2    Steering System Fault location

 Familiar with the car steering system of the common fault position, can accelerate the speed of fault diagnosis, fault diagnosis to improve the accuracy. Steering system of the common failure parts: the steering bodies of the ball hinge, steering rod, steering, steering wheel hub bearing; front wheel alignment and wheel alignment; power steering pump and drive, control valves, piping, regulators , pressure relief valves, working cylinder, piston and so on. Table 4-11 lists the car’s steering system damage in the form of the major components and performance of the fault.

 Auto after tire Abnormal  wear 

 Models: Santana LX model in 1996, the factory, the cumulative mileage is 300000km.

 Symptom: two rear axle tires wear faster, wear parts concentrated in the outer tire.

 Diagnosis and exclusion: abnormal tire wear, the most common of the two front wheels and drive wheels, and tires rarely support such a bridge failure. Santana’s rear axle to the overall longitudinal swing bridge, therefore, suspect that failure may be rear-wheel camber front and rear beam parameters are not allowed.

 On the car for wheel alignment test and found that the rear toe value exceeds the standard value, but not adjustable rear toe. Therefore, this failure is the rear axle deformation. In order to further diagnose the reasons of failure to do the test stand in the vehicle sideslip sideslip test, the result is excessive rear wheel spin out, basically confirmed the rear axle bent forward. Asked whether the bridge after the driver had a serious bump, the answer is there before, and since the occurrence of the bump, the rear wheel replaced more frequently than before. The rear axle of the vehicle for dismantling, adjustment repair, after a long drive, tire wear rate is essentially normal.

Analysis: car rear-wheel camber design, aims to improve traffic safety. Rear toe in order to compensate for the rear wheel camber resulting sideslip. Only in the amount of slip or no slip rear volume within the allowable range, the rear wheels to straight. Car rear toe value generally can not be adjusted, that no adjustment mechanism. If two wheels slip rear axle, that axle is deformed.

 Manual transmission Troubleshooting

 Related Links 6

 Manual transmission, there are two main types, namely three-axis and two axis. The main gear speed change mechanism and control by the institutions of two parts. Housing, shaft and bearing, gear and synchronizer gear and transmission gear selector is in the institutions, the main parts. In order to quickly and accurately determine and exclude manual transmission common faults, please read the mechanical transmission of the structural characteristics and working principle of such knowledge.
 For cars, buses and some trucks and driving position of the transmission far, the speed control mechanism is a remote control, the basic structure is: single-pole or double pole (double cable type). Car or on the commonly used double-pole double-cable-type structure.

 2.1   Common symptoms of a manual transmission

 Transmission of the common faults are: jump file, arbitrary files, hanging files difficulties, abnormal noise and oil spills. Similarly, the phenomenon of recognition failure according to the type of failure, and then analyzed to determine the methods and procedures proposed to exclude.

2.2  Common failure parts manual transmission

 Well-known transmission structure, working principle and the components common form of damage to determine and eliminate the transmission failure should have the basic knowledge. Car transmission is generally used on two axis. Its composition is also controlled by the gear speed change mechanism and the two major institutions, are characterized by the use of the file synchronizer; control mechanism is a long-range form, there are two shift and selector lever (cable) (commonly used on a single bus joystick and the corresponding coupling mechanism).

 2.3   Transmission fault diagnosis method or the law

 (1) hanging file, the clutch pedal, the engine can smoothly start, but after hanging file then start the engine hard, the friction cone synchronizer failure is damaged;
 (2) hanging file when serious metal crash, failure is the locking cone synchronizer damage;
 (3) before and after the depth of different stalls, the stalls are prone to shallow out files;
 (4) swap file is generally the initial file or directly in stalls;
 (5) the same fork axis of the two stalls easily swap file, failure on the axis of the self-locking mechanism;
 (6) If you are in neutral position, but which is also not linked stalls, this is a random file, failure is usually between the gear lever to shift fork;
 (7) If it is not hanging back a gear, this also is a random file, usually in the allocation of fault blocks, or sync on the fork;
 (8) If you can also put up two parking stalls, this random file for a fault in certainly interlock mechanism;
 (9) If at a certain position, the vehicle can not be driving, failure is usually rodents often the key between the wheel and shaft to be cut;
 (10) If the work in the case of the engine, the clutch pedal does not ring, release the pedal after the abnormal sound, the fault in the transmission;
 (11) If in any gear when the transmission are abnormal sound, failure is usually bent shaft or short of oil;
 (12) If there is abnormal sound transmission at low speeds, when the abnormal sound in the weakening or disappearance of high-speed, fault generally bearing wear.

Hydraulic control system “vapor lock” failure diagnostic

Model: CA7200 standard red car (hydraulic-operated clutch as shown in Figure 4-2), the factory in 1999, the cumulative mileage is 230000km. Symptom: Clutch must step on the pedal feet, or hanging file difficult. Troubleshooting: According to the clutch failure demonstrated the phenomenon shows that the clutch could be separated, just need to step on the pedal feet, the failure may, hydraulic operation Vertical system. Cause of the failure reasons: the clutch pedal free travel is too large, smaller hydraulic diameter of the pipe and makes the poor liquid flow, the hydraulic system to produce vapor lock phenomena. Where a cause of the fault location, but it? Can be obtained by the following test and be excluded: First check the clutch pedal free travel. If free travel does not meet the standard, remove the nut and circlip, take down pin, screw adjusting the U-shaped fork length to reach the U-shaped cross-axis center to the main cylinder block under the end flange distance of 1116.2mm , error of 0.2mm. If the clutch pedal free travel is normal, in the pedal when the clutch pedal feel sexy with or without shells. Without flexibility, and light the first leg, the second step on the foot can feel hard, clutch, clutch hydraulic system shows smaller diameter pipe. Pipes can be cleaned, together with the injection of hydraulic oil, exhaust, failure will be excluded. If you step on the pedal when you feel has the flexibility to explain the system with air. Through the test that, because of failure within the system inlet. Check the clutch master cylinder reservoir has been found within the surface to the lowest line. Add hydraulic oil to the upper limit, exclude the air within the system after the fault disappears. Exclude the air within the hydraulic system is: Clear the dirt outside the exhaust bolts, and then a transparent plastic tube of a screw inserted in the exhaust, the other end of the insert filled with brake fluid inside the cup, as shown, both to avoid the discharge of the brake liquid spilled on the ground, polluting the workplace, but also prevents the two mis-match due to the air to enter. One continuous step on the pedal until the pedal increased and hardened to remain intact, the other with a wrench to loosen the exhaust bolts, remove the mixture of oil and gas within the system quickly tighten the bolts. Two coordinated action, until no air bubbles in the liquid to exclude up. Finally, tighten and wipe the exhaust bolts.

 Related Links 5 Physical inspection of the car repair shop within the hydraulic system of air exclusion method steps, and write their comments and suggestions. Access to information, knowledge of rapid cleaning and replacement of hydraulic oil hydraulic equipment is used.

 Lack of engine power troubleshooting

(1) Symptom: When the engine is no normal load operation, but with a load of running speed is slow, uphill weakness, accelerate the pedal in the end when the power was still not
Feet, to enhance the very slow speed, reach maximum speed.

(2) Failure:
① air filter clogging;
② throttle to adjust properly, can not fully open;
③ the fuel pressure is too low;
④ battery voltage is too low;
⑤ injector blockage or poor atomization;
⑥ coolant temperature sensor fault;
⑦ air flow meter fault;
⑧ improper ignition timing or voltage spark is too weak;
⑨ engine cylinder compression pressure is too low.

(3) Troubleshooting:
① will accelerate the pedal in the end, check whether the throttle fully open. If you can not fully open, adjust the throttle cable or pedal.
② Check the air filter without clogging. If blocked, should be cleaned or replaced.
③ fault self-diagnosis to check for fault codes appear. Affect the power of the engine sensors and actuators are: coolant temperature sensor, air flow meter or the intake manifold absolute pressure sensor, ignition, fuel injection, etc.. Shown by the fault code to find the cause.
④ Check the throttle position sensor idle switch and full load switch is adjusted correctly. If incorrect, the standard should be re-adjusted.
⑤ Check the ignition timing. When the engine temperature is normal, when the ignition timing and idle speed when the ignition timing should be specified. Such as the idle ignition timing is incorrect, should be adjusted to the initial ignition advance angle; if the acceleration is not normal when the ignition timing, check the ignition timing control circuit and the crankshaft position sensor, ignition
Etc..
⑥ Check the coolant temperature sensor. At different temperatures, coolant temperature sensor resistance value should be changed according to the required standards. Do not meet the standard value, replace the coolant temperature sensor.
⑦ Check the air flow meter or the intake manifold pressure sensor. If abnormal, should be replaced.
⑧ Check the spark plugs of each cylinder, Gao pressure line, ignition coil, ignition, etc. If abnormal, should be replaced.
⑨ Check the fuel pressure. If the pressure is too low, should be further examination of electric fuel pump, oil pressure regulator, fuel filter and so on.
⑩ demolition injector, check the fuel injection quantity is normal. If the fuel injection quantity is not normal or poor atomization fuel injection, the injector should be cleaned or replaced.
? check the battery voltage. Battery voltage is too low will cause the injector fuel injection quantity reduced, resulting in lack of engine power, sluggish acceleration. If the battery voltage is too low, you should check the charging system or replace the battery.
? measuring cylinder compression pressure. If the pressure is too low, should be dismantling the engine.

Fluctuating idle fault diagnosis

 (1) Symptom: Engine idling speed is constantly fluctuating.

 (2) Failure:
 ① Idle switch (throttle position sensor> adjusted properly, the idle contact Idle switch not closed;
 ② bad or clogged injector spray;
 ③ air flow meter is faulty;
 ④ automatic idle speed control valve or idle speed control circuit is faulty;
 ⑤ coolant temperature sensor signal is not correct;
 ⑥ oxygen sensor failure or a feedback control circuit failure.

 (3) Troubleshooting:
 ① for fault diagnosis. Pay special attention to whether the throttle position sensor, coolant temperature sensor, air flow meter, oxygen sensor, idle speed control valve fault code. If the fault code, check the appropriate sensor and its circuit. Remove the cylinder-by-idle power lines or injector wiring harness plug, check the work of the engine cylinder is uniform. If you unplug the power lines of a cylinder or injector wiring harness plug, the engine speed drop is not obvious, indicating that the rainbow working poor, check the cylinder spark plug should be removed
 Or injector.
 ② Check the coolant temperature sensor resistance at different temperatures is in line with the standard value. Do not meet the standard value, replace the coolant temperature sensor.
 ③ Check the air flow meter and, if abnormal, should be replaced.
 ④ Remove the idle idle speed control valve in the wiring harness plug. If the idle up and down fluctuations disappears, but subsequently increased idle speed instability phenomenon, indicating the idle speed control valve is working properly, so the hate fuel injection system; If the idle speed fluctuation constant, then the bad idle speed control valve is working or not working. In this regard, should check the idle speed control valve
 Whether the pulse signal at the wiring harness plug. No signal, then the machine control circuit or a faulty meter grate; a signal, then the idle speed control valve stuck, check should be removed or replaced idle speed control valve.