The Difference and Detection Method between the Direct Injection Injector in the Cylinder and the Ordinary Injector

From:http://www.sinocmpinjector.com

How should we choose the fuel injector and which one do you use? Let's learn about it together.

The difference between the injector of the direct-injection engine in the cylinder and the ordinary injector： EFI and direct injection is not a side-by-side relationship. Electronic fuel injection is a computer-controlled fuel injection, which is more precise and smarter than that of the carburetor. The carburetor is mechanical, relatively primitive, and is basically no longer used.

Direct injection corresponds to ordinary injection. Direct injection refers to the direct injection of fuel into the cylinder. It requires high injection pressure, high injection accuracy, and large technical content. The advantages of direct injection are less fuel waste, fuel economy, complete combustion, and clean emissions. When the normal injection is used, the foot is sprayed into the intake port, and now most low-end cars are ordinary injection. The fuel injection nozzle is used for direct injection in the automobile cylinder. Direct injection in the cylinder is indeed a good technology, but it is a pity that domestic oil quality has an impact on this technology and it is difficult to achieve popularization.

What is the difference between the detection of the injector of the direct-injection engine in the cylinder and the ordinary injector The fuel injector is an important actuating element and also the most prone to malfunction. If the injector fails, it will not only affect the engine's forward rotation, but also cause a decline in power and economy, and even cause the engine to stop.

 The following is the example of the high-pressure direct injection engine currently used by Volkswagen. Its fuel injectors use 6-hole fuel injectors, and the internal structure is similar to traditional injection.

The motive control unit controls the fuel injector voltage to 65V. There is a DC / DC transformer inside the control unit to convert 12V to 65V. When the injector is turned on, it needs 12A of current. When the needle valve is opened and 65V electricity is applied, the needle valve continues to open and only a small 12V voltage is loaded. The end of the fuel injector is long and thin to improve the cooling effect. The fuel injector has a clamping clip that needs to be replaced as long as it is disassembled. If these are not taken into account, the test lamp can withstand high voltage, and it is feasible to detect it according to the method of port injection.

In this article, we introduced the difference between the direct injection injector in the cylinder and the ordinary injector. Do you want to know more?

The Structure Principle of Automobile Fuel Injector, the Fault Phenomenon of Fuel Injector

From:http://www.sinocmpinjector.com

What is a car fuel injector? I believe everyone has a common question in it. The fuel injector is a very important part of the gasoline EFI device. It controls fuel injection. If something goes wrong, it will affect the normal operation of the engine and will make the engine unnormal or stop immediately. According to the structure of the fuel injection port, the fuel injector can be divided into two types: shaft needle type and hole type. Let's take a look at the structural principle of the car's fuel injector with me.

Structural Principle of Automotive Injector---Introduction

The fuel injector is a key part of the car's electronic fuel injection device. It controls the final fuel injection. If something goes wrong, the engine will not work properly or stop working immediately. If the fuel injector is installed at the position of the original carburetor and is combined with the throttle valve, this form is called a single-point electronically controlled fuel injection. Its advantages are low cost and simple maintenance. The unequal distance leads to uneven fuel distribution, and the fuel easily adheres to the wall of the intake pipe when the cold engine is started.

If the fuel injector is installed on the intake pipe of each cylinder, this form is called the multi-point electronically controlled fuel injection device, which is the form currently adopted by most gasoline-electric injection engines. Its advantage is that each cylinder has its own fuel injector. The fuel injector is as close as possible to the intake valve, avoiding the shortcomings of single-point electronically controlled fuel injection. The disadvantage is high cost and complicated maintenance. At present, most automobile engines use multi-point EFI, and a small number of economic vehicles use single-point EFI. If the old fuel injector engine is converted to an electronic injection type, a single-point electronic injection type is used.

General automobile electronically controlled gasoline injection device consists of three parts: fuel supply part, gas supply part and control part. The fuel supply part is composed of a fuel tank, gasoline pump, gasoline filter, pressure regulator and fuel injector. The gasoline pump draws gasoline from the fuel tank and filters impurities through the gasoline filter. The negative pressure of the intake manifold is sent to the injector of each cylinder through the oil pipe. The injector is equivalent to a switch, the part that controls the switch is the ECU.

The fuel injector is controlled by the solenoid, and the on-off of the solenoid current is controlled by the ECU. The ECU processes the signal fed back by the sensor and sends an electrical signal to the fuel injector. This electrical signal determines the time when the fuel injector is turned on and the gasoline is injected. This time interval is called the "pulse width" of the fuel injector. After the solenoid coil of the injector is energized, it generates a magnetic field. Under the action of the magnetic field, the plunger is sucked up against the spring force and takes the valve body away from the valve seat. Gasoline is ejected from the nozzle port under pressure; when the solenoid coil is de-energized, the magnetic field It disappears, the plunger moves down under the force of the spring, the valve body closes the nozzle port against the valve seat, and the gasoline can't get out. The valve body is divided into two types: a ball valve and a needle valve. In order to ensure the accuracy of the fuel injection, the ball valve or the needle valve and the valve seat are required to have a high processing accuracy, and the lift of the valve body is small, only about 0.1 mm. Due to the role of a pressure regulator, the front of the injector is a high-pressure fuel path, and the rear is the low pressure of the intake manifold. The pressure difference forms a negative pressure to ensure that the fuel is sprayed into the vicinity of the intake valve.

The structural principle of automobile fuel injector-inspection methods of fuel injector

1. When the starter drives the engine to rotate, use a long handle screwdriver or stethoscope to listen to whether the injector has a "click, click" working sound. Use the method of unplugging and plugging the injector harness connector to identify whether the injector is working.

2. If the fuel injector does not work, a test light can be connected to the harness connector of the fuel injector to start the engine. If the test light flashes, it indicates that the injector control system is working properly, and the fault is in the injector. For the inspection of the fuel injector, a multimeter should be used to measure the resistance value of its electromagnetic coil. The resistance value is normal, indicating that the injector is blocked (affected by the carbon deposits generated during combustion and the gum in the fuel. This phenomenon is most common), the needle valve is stuck, etc., the injector should be repaired, cleaned or replaced; If it is normal, the fuel injector must be replaced.
3. If the test light does not work, it means that the control system or circuit of the fuel injector is faulty. In this regard, you should first check whether the related lines of the fuel injector are intact, and only after ensuring that the external lines are good, can you determine that the computer is defective.

The structural principle of automobile fuel injector-maintenance of fuel injector

The injector should be checked and adjusted once after working for about 700h. If the opening pressure is lower than the specified value of 1Mpa or more, or the carbon deposit on the head of the needle valve is serious, the needle valve should be removed and put into clean diesel oil to scrape off the carbon deposit with wood chips. The injection pressure difference of each cylinder of the same machine must be less than 1Mpa. In order to enable the diesel fuel injected into the cylinder by the fuel injector to burn completely in time, the fuel supply time of the fuel pump must be checked regularly. If the fuel supply time is too early, the vehicle will have difficulty in starting and failure of knocking the cylinder; if the fuel supply time is too late, it will cause black smoke in the exhaust, the engine temperature will be too high, and fuel consumption will increase. The fitting precision of the needle valve coupler of the injector is extremely high, and the hole diameter of the injection hole is very small, so the clean diesel oil of the specified brand must be selected strictly according to the seasonal changes, otherwise, the injector will not work properly.

Do not collide with other hard objects when cleaning the needle valve assembly of the fuel injector, and do not let it fall to the ground to avoid bruising. When replacing the needle valve coupler of the injector, the new coupler should be immersed in hot diesel oil at 80 ℃ for about 10 s to allow the anti-rust oil to fully melt, and then the needle valve should be pumped back and forth in the valve body in clean diesel, Wash thoroughly, so as to avoid the trouble of sticking to the needle valve due to the melting of the anti-rust oil when the injector is working.

Whether the fuel injector can work normally depends on whether we maintain it properly. Check whether the fuel injector is injecting oil: when the oil pump works normally, check the fuel injector. Start the engine and touch the fuel injector with a stethoscope to hear the sound of work. No sound, the fuel injector does not work. Then use a high-impedance test light, connect it to the harness connector of the fuel injector, and start the engine. If the test light is on, it indicates that the control circuit of the fuel injector is normal. If the fault is in the fuel injector, it should be replaced. If the test light is off, the fault is in the injector control circuit. I hope that the relevant information I shared about the structural principles of automobile fuel injectors can help buyers and your customers.

Inspection and Maintenance of Diesel Fuel Injector

From:http://www.sinocmpinjector.com

The fuel injector is one of the most important devices in the fuel supply system of the diesel engine, which can spray the diesel oil into the cylinder uniformly, finely and evenly to make it mix with the compressed air in the cylinder evenly and form a good combustible mixture. Its working quality directly affects the power, economy and service life of diesel engines. In the process of using and maintaining the diesel engine, some minor negligence may lead to major faults.

1 Injector detection

The performance index of fuel injector mainly includes the following three items:
(1) inspection of fuel injection pressure. If the injection pressure does not meet the standard, it will seriously affect the power and economy of the diesel engine. If the injection pressure is too low, the oil beam velocity, range and spray cone angle will be reduced, which will make the diesel atomization not good and produce the phenomenon of dropping oil. At the same time, it will cause the injection time to advance and the injection quantity to increase after the end of the injection. This will result in incomplete combustion, black smoke from the exhaust gas, carbon deposition, and fuel injector seizure. On the contrary, if the injection pressure is too high, the diesel leakage will increase, the injection duration will shorten, the injection amount will decrease and the diesel engine will work rough. At the same time, it will increase the wear of the fuel injector and other related parts. The injector injection pressure check can be performed on the diesel engine. Connect a tee joint to the outlet pipe of the high-pressure oil pump, and connect the other two ends with the standard injector (the same model as the injector to be tested, and the injection pressure is the standard value) and the injector to be tested. The diesel engine is turned over and the fuel is supplied by the high-pressure oil pump. If the two injectors simultaneously spray oil and the spray quality is the same, the fuel injector is qualified. If the tested injector injects fuel first, it means that the injection pressure is low, then tighten the pressure regulating nut until the two injectors inject fuel at the same time.

(2) Check the injection advance angle. The injection advance angle is different from the supply advance angle. The fuel supply advance angle refers to the crankshaft angle from the piston position of the first cylinder to the top dead center when the first cylinder plunger pair of the fuel injection pump starts to supply oil. The fuel injection advance angle refers to the crankshaft angle from the piston position of the first cylinder to the TDC when the fuel injector of the first cylinder starts to inject fuel into the cylinder. Obviously, the injection advance angle is smaller than the oil supply advance angle, generally less than about 8 °C. This is related to the structure of the injection pump and the length of the high-pressure oil pipe.

2 Precautions for disassembly and repair

(1) Carefully dismantle the fuel injector, and ask the maintenance personnel not to dismantle the fuel injector blindly, and operate in strict accordance with the operating procedures. When the fuel injector is repaired, it often happens that the quality of the sprayer with good atomizing quality is deteriorated after being disassembled, cleaned and reassembled. This is because the sealing ring belt between the needle valve cone of the nozzle and the cone hole of the valve body of the nozzle has been worn, but it is still sealed well. Once it is disassembled and reassembled, the original well-sealed fitting position of the needle valve in the needle valve body is damaged. Therefore, it should not be disassembled without inspection of the injector tester and confirmation of disassembly.

(2) When the fuel injector is installed after replacement, cleaning or troubleshooting, the appropriate thickness of the sealing adjusting pad shall be selected according to the requirements of technical conditions to ensure the depth of the fuel injector into the combustion chamber. So as to ensure the formation quality of the combustible mixture. When assembling the fuel injector after cleaning and troubleshooting, make sure that the coupling parts are used in pairs. The spray needle and nozzle are all components with grinding matching, and the matching clearance is 0.002-0.004 mm. In case of any pairing, the sealing between the spray needle and the nozzle will be affected. When assembling the injector, the impurities in the inner cavity of the nozzle shall be completely removed to prevent the injector from sticking (the upper clamp is not sealed, and the lower clamp is not injected).

Trouble Analysis and Elimination of Diesel Injector

From:http://www.sinocmpinjector.com

Abstract: Injector is a component with a high failure rate of a diesel engine. It analyzes the problems such as dripping oil from the injector, the inadequate seal between the needle valve and valve body, and seizure. Problems to be paid attention to during inspection, and a treatment method for worn injector parts was proposed.

The fuel injector is one of the key components of the diesel fuel system and is also a wearing part. The technical status of the injector has a direct impact on the performance of the diesel engine. Whenever the vehicle has insufficient power and abnormal smoke exhaust, the first thing that the repairman thinks of is to check the fuel injector to see if its atomization quality, fuel injection pressure, and sealing performance are satisfactory. If these three performance indicators are not satisfactory, find and troubleshoot further.


1 Common fault analysis of injector     

1.1 Drip oil from the injector

Failure phenomenon: fuel injection continues, nozzle holes are blocked, fuel can not be atomized, fuel injection is uneven, poor stability, working knock, exhaust smoke, carbon deposits increase, resulting in decreased engine power, increased fuel consumption, and increased wear.

Failure cause analysis:
(1) the needle valve and needle valve body sealing cone surface wear severely, and groove marks appear, which widens the contact surface of the cone sealing ring belt, deforms the cone surface, increases the roughness, and causes oil dripping from the injector. Carbon deposits formed near the spray holes and even blocked the spray holes.

(2) The higher the residual pressure of the high-pressure fuel pipe (that is, the pressure when the high-pressure fuel pipe is not injecting fuel between the two injections of the injector), the more oil drips from the injector, and the main reason affecting the residual pressure is the oil valve Pieces. The oil dripping faults of the fuel injector is not all on the fuel injector but have a close relationship with the tightness of the valve assembly. Abnormal wear of the oil outlet valve will cause oil dripping from the injector.

(3) Insufficient sliding between needle valve and needle valve body guide surface, work retardation, or serious wear of needle valve and needle valve body guide surface, inadequate contact between the needle valve body and injector body, or needle valve and needle The sealing cone surface of the valve body is cushioned by mechanical impurities, and if it is not tightly closed, the fuel injection nozzle will drip oil.

1.2 Injector needle valve and valve body are not tightly sealed and bite

Symptoms of failure: The low-pressure oil circuit is unblocked. After the speed control handle is put to the fuel supply position, the diesel engine is turned. Individual cylinders cannot hear the sound of fuel injection from the injector. The exhaust pipe emits white smoke and is not easy to catch fire. When the diesel engine catches fire, the exhaust pipe still emits smoke, and the idling speed is not stable, accompanied by the gasping sound of "Teng, Teng", and the knocking of the cylinder at high speeds and throttles. When the temperature of the diesel engine rises, the exhaust pipe emits black smoke, the fuel injector burns, and it catches fire. Disconnect the high-pressure tubing from the missing leg cylinder. The diesel exhaust pipe no longer smoked, and the sound of knocking cylinders disappeared. However, there is an exhaust phenomenon at the high-pressure oil pipe joint of the injector and foam is discharged.

Failure cause analysis:
(1) During the operation of the diesel engine, the high-pressure diesel pumped from the fuel injection pump carried some mechanical impurities, entered the fuel injector and adhered to the sealing cone of the needle valve body, causing card issuance and cushioning, resulting in contact. Not tight.

(2) Due to the ablation of high-pressure and high-temperature gas in the combustion chamber, and frequent washing of mechanical impurities in the fuel, pits, and pits appear on the sealing ring of the needle valve and the needle valve body, resulting in the needle valve and the valve body The sealing performance deteriorates, and the phenomenon is that the oil return amount at the oil return hole of the injector increases. In this way, the high-pressure and high-temperature gas in the combustion chamber during work will enter the annular oil chamber of the injector. Under the action of high temperature, the injector needle valve and the valve body are thermally expanded and bite each other.

(3) Too much mechanical impurities in diesel will also cause the impurities to enter between the needle valve and the guide surface of the valve body and die. Because the needle valve of the injector and the valve body is seized, the atomization performance of the diesel becomes poor, which makes the injection time too short and extends slightly backward, resulting in a short ignition period, which makes the diesel engine rough. Therefore, the diesel engine issued " "Teng, Teng" sound and obvious knock sound.

(4) The injector needle valve and valve body are not tightly sealed or bite in the open position, causing the high-temperature gas in the combustion chamber to enter the annular oil chamber of the injector, causing the injector to be hot. If the diesel engine is shaken in this state, the compressed air generated in the cylinder will enter the annular oil chamber and oil passage through the opened nozzles and will be discharged from the high-pressure oil pipe, thus showing the phenomenon of high-pressure oil pipe exhaust.

 2 Injector inspection

The inspection and adjustment of the injector assembly at some service points were too extensive. Some only check and adjust the starting fuel injection pressure, reducing some items that should not be simplified. This is not correct. We believe that the adjustment should be carried out according to the process specifications. Not only should the standard injection pressure be checked and adjusted, but also the spray cone angle and injection quality should be further checked according to the specific situation, especially for the tightness check of the injector. Get full attention.

Checking the tightness of the injector: performed on the injector tester, taking the porous long injector as an example, increasing the predetermined pressure of the injector tester to 23 to 24 MPa, and adjusting the injection pressure of the injector As high as 24 to 25 MPa, when the injector tester pressure is reduced from 20 MPa to 18 MPa, the standard injector should last 9 to 20 s, and the allowable use should not be less than 9 s.

It is worth noting: First, the injector tester must meet the technical requirements, the high-pressure oil circuit should be tight, and the tightness of the oil valve assembly itself on the tester should be good. Exclude the air in the oil circuit, block the high-pressure oil outlet joint, continue to supply oil and increase the pressure to increase the predetermined pressure to 23 to 24 MPa. When the tester pressure is reduced from 20 MPa to 18 MPa, it should last no less than 3 minutes. Secondly, check the injectors no less than twice, and take the average value. And the difference between the two adjacent durations must not be greater than 2 s for shaft pins and flat plates; for porous long types, it must not be greater than 3 s.

3 Troubleshooting     

After the injector needle valve and valve body are not tightly sealed, biting each other or dripping oil, the injector should be removed first and the needle valve and valve body should be cleaned with clean diesel. If there are slight pits and pits on the sealing cone of the needle valve and the valve body, it should be ground on special equipment or pliers (note that the abrasive paste must not enter the sliding surface of the needle valve and the valve body), and then Grind with engine oil until the pits and pits on the sealing cone surface of the needle valve and valve body disappear and appear black and bright. For the needle valve and the valve body that is bitten by the needle, the needle valve should be taken out with pliers, and then cleaned in clean diesel oil. Then use a relatively fine oil stone or sand bar to smooth the stuck protrusion. (Be careful not to damage other parts), make the needle valve slide freely in the valve body, and then use the polishing paste and oil to grind the sealing cone surface to the above requirements. If the pits and pits on the sealing cone surface of the needle valve and the valve body are too deep and cannot be repaired, the new injector should be replaced, and the injection pressure and fuel atomization quality should be adjusted on the test bench or car. Make it meet the requirements for use.

The Philippines PHIL CONSTRUCT 2019

From:http://www.sinocmpinjector.com

In order to integrate the SINOCMP brand into the international market and better understand the needs of the target market, the CMP technology combines products online and offline in 2019 to launch its products globally.

On November 7, 2019, the Philippines PHIL CONSTRUCT 2019 was held as scheduled at the SMX Convention Center, Manila, Philippines & World Trade Center. The exhibits were mainly engineering and mining machinery: construction machinery, excavators, forklifts, bulldozers, belt conveyor systems, Cranes, crushing equipment, pumping station equipment, rock drilling equipment, safety equipment, and products, seamless pressure pipes, sensors, etc.


The exhibition has been held every year since 1991. This exhibition has become the country's largest exhibition of construction materials. In the last exhibition, there were nearly 500 exhibitors, nearly 60,000 visitors, 900 booths, an exhibition area of ​​32,090 square meters, and a turnover of 2.37 billion US dollars.


At this exhibition, we exhibited excavator electrical products, computer versions, monitors, sensors, solenoid valves, tool products, pressure gauges, and engine products, etc.

At this exhibition, we met many old customers from the Philippines, discussed the cooperation in previous years and further consolidated the long-term development in the future.

In addition to meeting old customers, our colleagues explained the product knowledge and analysis of the Philippines market with passion, so that more new exhibitors showed great interest in our products.

During these days, all of our exhibited products were sold out at the exhibition, giving us further confidence in the development of this market. In the future development, we will further consider investigating the target customer market and let SINOCMP move towards global.

The Symptom of the Broken Injector and How to Deal With it

From:http://www.sinocmpinjector.com

The injector is an indispensable part of the injector. As the seller and user of the fuel injector, we can not only solve the problem by ourselves but also provide a lot of convenience for your customers. When the nozzle is broken, the nozzle will block, fail to open, and the fuel-injected will not form a mist, which will generally cause the engine to run unsteadily or even fail to run; when the fuel injector leaks and other faults, it will also cause excessive fuel consumption or even exhaust black smoke and other phenomena. The short circuit and open circuit fault of the control circuit of the fuel injector often occur, which leads to the failure of the fuel injector to inject or continue to inject fuel, resulting in the failure of the engine to start, unstable operation or serious black smoke from the exhaust. It can be seen that the detection and maintenance of the fuel injector and its control circuit is an important part of the maintenance of the electronic control engine.

Trouble symptoms of a damaged fuel injection nozzle

The failure of the fuel injector will directly lead to the abnormal phenomenon of the engine. The failure phenomena of the engine fuel injector are as follows:
(1) Black smoke from the exhaust pipe.
(2) The operation of each cylinder is uneven, and the engine has obvious vibration.
(3) Engine power reduction.
(4) Weak driving.

 In order to judge the fault of the engine injector, the engine can be idled, and the fuel cut-off test is carried out for each cylinder in turn. When the fuel injection the nozzle of a certain cylinder stops supplying oil, pays attention to the working condition and sound of the engine. If the exhaust no longer emits black smoke after oil cut-off and the engine speed changes, it is the cylinder injector failure. Remove the fuel injector and check it on the fuel injector calibration bench after the troubleshooting judgment of the engine fuel injector is accurate.


What are the symptoms of the broken injector

The injector is actually a solenoid valve, with its nozzle facing the intake valve and its tail connected with the fuel distribution pipe. When the engine ECU sends out the fuel injection command in the form of electric pulse, the electromagnetic coil inside the fuel injector is electrified to generate magnetism, so that the injection hole is opened, and fuel is injected into the engine. When the ECU's fuel injection command is over, the injection hole is closed under the action of the return spring. The duration (i.e. fuel injection volume) for the injection process to stop the opening of the injection hole immediately is determined by the width of the electric pulse sent by the ECU.

Generally, the internal open circuit and short circuit fault of the injector can be judged by measuring its resistance, but the blocking, dripping, spray fuel can not form fog and other situations need to be detected and repaired on a special injector cleaning and testing test bench. The fault of the control circuit of the fuel injector needs to be detected with the multimeter, test lamp, and other tools.

(1) Measure the resistance of the fuel injector

Unplug the fuel injector plug, and use a multimeter to measure the resistance between the two pins of the fuel injector, which should meet the requirements of the maintenance manual (the resistance value of the low resistance fuel injector is 2-3g2, and the resistance value of the high resistance fuel injector is generally 13-179). If not, replace the fuel injector.

(2) Check the operation of the fuel injector

Start the engine and touch the surface of the fuel injector by hand. You should be able to feel the vibration caused by the opening and closing of the fuel injector. You can also hear the working sound of the fuel injector with the touch bar stethoscope.

If the vibration of the fuel injector can not be felt or the sound of the fuel injector working can not be heard, the test can be conducted by the method of artificial power.

The method is: Unplug the electrical plug of the injector, connect one pin of the injector to 12V power supply (for low resistance injector, a resistance of about 10 Ω should be connected in series in the circuit, or get the power supply from the original plug of the injector), use the wire to touch the other pin to ground intermittently, which should be able to hear the "click" sound of the injector, otherwise, replace the injector.

If the fuel injector is normal when tested by artificial power on method, but the fuel injector does not work when starting the engine, it means that there is a fault in the control circuit of the fuel injector. Check the control circuit of the fuel injector.

(3) Fuel injector power supply inspection

Unplug the electric plug of the fuel injector, turn on the ignition switch and measure the grounding voltage of the power pin in the plug with a multimeter, which should be 12V. Otherwise, check the power circuit.


What to do if the nozzle is broken

The failure of the fuel injector is generally as follows:
(1) The injection pressure of injector is too low
(2) No atomization or obvious downward injection
(3) The length and the length of the fuel injection bunches at each injection hole of the fuel injection nozzle are different, and the fuel bunches are not uniform
(4) Dripping of fuel injector
(5) The injection nozzle needle valve is stuck and burnt.

After the above conditions occur to the fuel injector, the fuel injector shall be removed for repair. If the damage is serious, it should be replaced. After replacement, the injection pressure should be adjusted to 22-0.5P a, and the spray condition is good without dropping oil.

The failure of the fuel injection nozzle is mainly caused by the problems of fuel and filter, such as the use of poor quality diesel fuel, the long-term use of filter elements without cleaning or replacement. It is recommended that the user use fuel that meets the national standard.

Clean the fuel filter regularly to prevent oil impurities from blocking the fuel nozzle.

If you want to know more about injector, please contact us!

Analysis of Injector Fault Codes P0261 P0262 and P0201

From：http://www.sinocmpinjector.com

The fuel injection of the injector (usually called the fuel injection end in maintenance) is controlled by the electromagnetic room. After the precise calculation of the fuel injection quantity and the injection time, the fuel is sent into the cylinder, which can make the fuel produce the best combustion under various loads and speeds. After the air temperature, pressure signal and oxygen sensor signal are input to the PCM, the PCM outputs the driving signal to the fuel injector after internal calculation, so as to maintain the air-fuel ratio at the desired value.

The injection end is a small and precise solenoid valve. When the PCM supplies the grounding signal of the fuel injection isolating circuit, the coil of the fuel injection nozzle will be energized, and the energized coil will pull the pins back and let the fuel flow through the nozzle into the combustion chamber. The amount of fuel injected depends on the duration of the injection pulse. The pulse duration is the length of time that the injection interval remains open. The PCM controls the duration of the injection pulse according to the fuel demand of the engine.

The injector fault codes are as follows:

DTC: fault description/fault code interpretation

P0261: injector 1 control circuit low voltage
P0262: injector 1 control circuit high voltage
P0264: injector 2 control circuit low voltage
P0265: injector 2 control circuit high voltage
P0267: injector 3 control circuit low voltage
P0268: injector 3 control circuit high voltage
P0270: injector 4 control circuit low voltage
P0271: injector 4 control circuit high voltage
P0273: injector 5 control circuit low voltage
P0274: injector 5 control circuit high voltage
P0276: injector 6 control circuit low voltage
P0277: injector 6 control circuit high voltage
P0201: injector 1 control circuit (open circuit)
P0202: injector 2 control circuit (open circuit)
P0203: injector 3 control circuit (open circuit)
P0204: injector 4 control circuit (open circuit)
P0205: injector 5 control circuit (open circuit)
P0206: injector 6 control circuit (open circuit)

1. Analysis of Fault Code P0261

Fault description: injector 1 control circuit low voltage Possible causes of failure.
a. The fuse of the fuel injection nozzle is damaged.
b. Fuel injection ends circuit open circuit. Injector failure.

Fault generation principle:
The PCM activates the corresponding injector pulses for each cylinder. The fuel injector supply voltage is provided by the required battery. The control module ground the control circuit through the solid-state device of the driver to control each injector, and the control module monitors the status of each driver. If the control module detects that the voltage corresponding to the driver command status is incorrect, an injector control circuit DTC sets.

Fault identification conditions:
The ECM detects a short to ground in the injector high voltage control circuit for more than 2S.

When the fuel pump relay operates normally, the system fuel pressure is maintained at 300-350KPA, and the system power supply voltage is between 11-16v, if the injector driving transistor in PCM feels that the actual voltage value and the timing of the injector actuation do not meet the set standard value, the fault code p0261 will be set.

2. Analysis of Fault Code P0262

Fault description: injector 1 control circuit high voltage.

Possible causes of failure:
① The fuse of the fuel injection nozzle is damaged.
② The harness connector of the fuel injector is poor.
③ The injector circuit is shorted to ground.
④ Injector failure.

Fault generation principle:
The PCM activates the corresponding injector pulses for each cylinder. The power supply voltage of the injector is provided by the battery. The control module grounds the control circuit through the driver's solid-state device to control each injector. The control module monitors the status of each driver. If the control module detects that the voltage corresponding to the driver command status is incorrect, an injector control circuit DTC sets.

Fault identification conditions:
The ECM detects a short to voltage in the injector high voltage control circuit for more than 2S.

When the fuel pump relay operates normally, the system fuel pressure is maintained at 300-350kpa, and the system power supply voltage is between 11-16v if the injection order in PCM drives the quality control system, and it is detected that the actual voltage value and the timing of the injection nozzle actuation do not meet the set standard value, the fault code P0262 is set.

3. Analysis of Fault Code P0201

Fault description:
injector 1 control circuit open circuit, this diagnosis monitors the electrical control of the fuel injection end.

Cause of failure :
① The electric wire harness between the engine control unit and fuel injector 1 is damaged.
② Injector 1 is damaged.

Principle of fault generation:
If the injector voltage is more than 210v and the charge on the injector is less than 300uA. S, the fault is identified and the fault code P0201 is set.

Fault identification conditions:
① Under voltage condition: the vehicle network voltage is more than 10V.
Under the condition of temperature: the coolant temperature is more than - 20 ℃.
② Time condition: none.
③ Other conditions engine running.

Fault storage condition and display record fault immediately.
Troubleshooting measures:
① Check electric wire harness between PCM and fuel injector 1.
② Check the injector 1 and measure the resistance [standard value (200 ± 10) k Ω] between the pins of the injector. If the standard value is not reached, replace the injector.

Injector Failure Phenomenon and Good or Bad Detection Method

From: http://www.sinocmpinjector.com

In the process of using the injector, we will encounter many problems. Let us learn and understand the Injector failure phenomenon and good or bad detection method.

Injector Failure Phenomenon:

If the engine fuel system lacks maintenance (regularly clean the injectors), it may cause glue accumulation inside the injector and the valve hole will be blocked or the needle valve stuck.
Blocked injector valve holes will result in the inability to inject fuel (full blockage) or poor injection atomization (partial blockage), and stuck needle valves will cause dripping after injection, resulting in engine idling instability, poor acceleration or difficulty in starting. This phenomenon will also seriously affect the emission performance of the engine.
In addition, the water inlet of the injector connector will cause a short circuit, which will make it impossible to inject fuel. Care must be taken when cleaning. The engine fails to start, the engine runs erratically, and the exhaust gas emits severe black smoke. These are all symptoms of a broken injector.

The main fault types of injectors:

1. The valve hole is blocked and fuel injection or atomization is bad.
2. The needle valve malfunction causes flow error or leakage after injection.
3. Unable to inject fuel due to the open/short circuit of the connector.

Injector performance check method:

 1. Listen to working sound detection:

When the engine is running or starting, check the working sound of the injector with a noise stethoscope or similar tool. The operating sound cycle of the injector changes with engine speed. in case no sound or abnormal sound is heard, check the injector circuit (wiring or connector) or injector.



 

2. Resistance check:

Turn off the ignition switch and disconnect the injector connector. Use a multimeter to measure the resistance between the two terminals of the injector. It should be 12Ω at 20 ° C (68 ° F).





                                                                  3. Flow and leak inspection:

(1) Assemble the injector and transfer tool.
(2) Install a suitable vinyl tube to the injector to prevent fuel from splattering during the injection.
(3) Put the measuring cylinder under the injector.
(4) Run the fuel pump and deliver fuel to the injector.
a. Connect the tester to the DLC and execute the "component test" mode to drive the electric fuel pump to work.
b. Disconnect the fuel pump relay connector, and short the two terminals of the fuel pump relay with the maintenance wire to force drive the electric fuel pump.
(5) Use the accumulator to apply voltage to the injector for 15 seconds, measure the amount of fuel sprayed with a graduated cylinder, and measure 2-3 times per injector. The reference value for fuel injection is approximately 46cc / 15sec. If the measured value clearly exceeds the technical specifications, replace the injector.
(6) Check the leakage of the injector nozzle. Do not run the nozzle during this check (but the fuel pump should work). If the fuel leakage exceeds 1 drop/minute, replace it.

Introduction to the inspection method of the fuel injector

1. When the starter drives the engine to rotate, use a long-handled screwdriver or stethoscope to listen to whether the fuel injector has a "click, click" working sound. , At the same time of auscultation, the method of unplugging and reconnecting the injector harness plug can be used to identify whether the injector is working.
2. If the fuel injector does not work, connect the test lamp to the fuel injector's harness plug before starting the engine. If the test light flashes, the injector control system is working normally and the fault is in the injector. To check the injector, use a multimeter to measure the resistance of the solenoid coil. If the resistance value is normal, it means that the injector is blocked, the needle valve is stuck, etc., the injector should be repaired, cleaned or replaced; if the resistance value is abnormal, the injector must be replaced.
3. If the test light is off, the control system or circuit of the injector is faulty. In this regard, you should first check whether the relevant circuit of the injector is intact, and make sure that the computer is faulty under the condition that the external circuit is good.

Injector maintenance precautions:

1. Using a special cleaning analyzer to thoroughly clean the injectors on a regular basis can greatly improve the life of the injectors, and the power, fuel consumption, and emission performance can be maintained in good condition.
2. The top of the injector uses a rubber seal to connect with the fuel rail to form a reliable pressure fuel seal. The bottom also uses a rubber seal and the engine intake manifold to seal the air. Both of these parts must be replaced when the injector is disassembled.
3. When installing the injector or fuel supply pipe, first lubricate the O-ring with gasoline.
If you want to know more about the injector's failure phenomenon and more ways to check the quality of the injector, please contact us！

Maintenance Method and Failure Case Analysis of Fuel Injector

From: http://www.sinocmpinjector.com

The following SINOCMP introduces the maintenance method of the injector and the failure case analysis of the injector of the 5 kinds of cars.

(1) Structure of the injector

 Figure: injector structure

The injector is installed on the intake pipe of each cylinder, 70-100mm away from the centerline of the intake valve, and the spray shape is a circular dimension of 25. The structure of the injector is shown in the figure.
There are two O-ring on the injector, and the lower seal ring is located between the injector and the air inlet. Each time the injector is removed, the lubrication seal circle must be replaced. The O-shaped sealing circle has a thermal insulation effect, which can prevent fuel from forming air resistance in the injector, thereby improving the hot start performance, and also preventing the injector from being excessively perturbed. The upper seal chart is used to ensure the seal between the injector and the fuel manifold. Fuel pressure is 250 ~ 350kpa, the impedance of the electromagnetic coil is 12.2Ω, high impedance.

(2)Disassembly of the injector

Dismantle the fuel injector to prevent damage to the conductive needle post and fuel injection hole in the connector. The injector assembly cannot be cleaned in any cleaning agent.
When disassembling, the fuel main should be fixed to prevent damage to other components. Replacement of the injector must use the same model and the same flow of injector. The removal steps are as follows:
[1] Release fuel system pressure.
[2] Remove the intake manifold.
[3] Remove the electrical connector and fuel main.
[4] Remove the retaining clip and remove the fuel injection pipe from the fuel main pipe.
[5] During installation, proceed in the reverse order of removal. The O-ring must be replaced with a new one.

Inspection method of fuel injector

  Figure: Detecting the solenoid coil resistance of the injector

(1) Check the fuel injector on the car Proceed as follows:

[1] When the engine is running, place your finger on the injector and feel the vibration as normal.
[2] Unplug the control plug of a certain cylinder injector during engine operation. If the engine speed drops or is unstable, it means that the cylinder injection is working normally.
[3] Detect the solenoid coil resistance of the injector as shown in Figure 1-80. Low-resistance fuel injection, high precision digital multimeter detection. Cold start oil injector resistance value is 2-5Ω is normal, low resistance value injector is normal at 1.5-3Ω, the high resistance value of the main injector is about 13Ω. The coil must not be short-circuited, open-circuited, or grounded, otherwise, it should be replaced.

(2) Fuel injection test

[1] Spray test. Remove the fuel injector, connect the fuel supply pipe and the battery or connect the 3V power supply, and touch the positive electrode of the battery with a wire.
[2] Oil drop test. Do not power up the injector, but the electric fuel pump continues to pump oil. It is normal for the fuel injection nozzle to drop more than 1 drop per minute.

Figure: Injector fuel injection test

[3] The fuel injection test of the fuel injector is shown in the figure. Connect the fuel injector to the rich battery for 15s to see the fuel injection quantity. Each model has specific requirements, and relevant information should be consulted. Check the fuel injection volume difference of all injectors. Generally, it cannot be greater than 5mL in 15s.
[4] Simple inspection method. Two dry batteries (approximately 3V) can be connected to the injector to blow air to the injector. When it is not energized, it cannot be blown, and air leakage is normal; when it is energized, it is normal to blow.

Injector maintenance example 1
Model:  Fukang AL car.
(1) Failure phenomenon, rapid instability, engine speed fluctuates between 700-800rmin, the engine is susceptible to fire when cold, and the engine power is insufficient during driving.

(2) Causes of the fault The fuel injector is glued due to dirty fuel, the fuel injection quantity is insufficient, the air-fuel ratio is incorrect, causing rapid instability and insufficient engine power.

(3) Diagnosis and exclusion methods
[1] The computer detects the mixing ratio concentration and automatically adapts to temporary failures.
[2] Clean the valve body, inlet pressure sensor and pipeline of the total speed rotary valve.
[3] Check the ignition timing.
[4] Replacing 93 # gasoline, the effect is not obvious.
[5] Check the fuel system pressure at 250kPa, which is normal.
[6] Check that the fuel injection is dirty, and the vehicle returns to normal after cleaning.

Injector maintenance example 2
Model: Fukang 988.
(1) Failure phenomenon The vehicle runs normally. When the vehicle is parked for more than 10mm, it is difficult to start the engine. Enlarging the throttle opening can start the engine.

(2) The cause of the fault is the poor seal of the injector, the gasoline leaked from the injector into the interior of the gas red, and the starting gas is too rich to cause difficulty in starting.

(3) Diagnosis and exclusion methods
[1] Check that the fuel pressure is normal.
[2] Check that the high-voltage power of the ignition system works normally.
[3] Clean quick reading and intake pressure sensor.
[4] The smell of gasoline was found when the spark base was disassembled.
[5] After removing the injector and cleaning it, the injector has leaked oil. After replacing the injector, the engine starts normally.

Injector maintenance example 3
Model: Jetta GT.
(1) Failure phenomenon The engine has insufficient power, poor acceleration, and unstable speed.

(2) Fault diagnosis
[1] Query no fault code storage with VAG1552 fault diagnosis instrument.
[2] Check that the warehouse speed HC exceeds the standard.
[3] Check that the spark plug is working properly.
[4] Removed the injector and found that there were two red fuel injection plugs.

(3) Elimination method After the fuel injector is cleaned and tested, the engine works normally.

Injector maintenance example 4
Model: Suda GT
(1) Failure phenomenon The color speed of the engine is trembling.

(2) Fault diagnosis
[1] Query no fault code storage with VAG1552 fault diagnosis instrument
[2] Inspection found that there was a bad seal of the red injector.

(3) Elimination method After the fuel injection seal ring was replaced, the engine was running normally.

Injector maintenance example 5
Model: GTX type of car.
(1) Failure phenomenon The engine accelerates badly.

(2) Fault diagnosis
[1] Use the VAG1552 fault diagnosis instrument to query the storage of unreasonable code.
[2] Check that the idle exhaust gas is normal.
[3] Check that the wire from the injector to the ECU is frayed, and the fuel injection of the injector is out of control.

(3) Elimination method After the broken wire is repaired and tested, the engine accelerates well.