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.