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You are here: Home » Blogs » KNOWLEDGE » High/Low Pressure Oli Passage of the Engine(IMV)

High/Low Pressure Oli Passage of the Engine(IMV)

Author:Site Editor     Publish Time: 2020-12-11      Origin:Site

Working Principle:

Adjust the opening of the valve to control the amount of fuel flowing into the high-pressure fuel pump. When the control signal is not applied, the amount of fuel in the high-pressure fuel pump is the largest.

IMV curve of flow characteristics

Function and Effect:

It is used to adjust the pressure of the fuel in the high-pressure fuel rail, optimize the atomization, combustion, and discharge of the fuel, and reduce the power consumption of the high-pressure fuel pump.

IMV hardware control circuit

Performance After Failure:

After the failure, the IMV valve is completely closed. If the engine is stopped, it cannot be started; if the engine is running, it will stop the engine.

After the failure, the IMV valve is fully opened. The quick opening discharge port (RVD) of the injector and the pressure limiting valve on the high pressure rail will ensure that the rail pressure will not exceed the safety limit.

After a IMV fails, the maximum torque will be reduced (50% can be scaled).

When the IMV common rail system fails to start successfully, the decoder reads the following fault code:

P0087: The starter speed is too low and the rail pressure cannot be established.

P1253: IMV valve controller error (pressure is too high, negative electrode failure).

P1254: IMV valve controller error (pressure is too high, positive electrode failure).

P1257: IMV valve controller adjustment error (IMV valve adjustment current is too high).

Two faults were read in the common rail system, one was that the rail pressure could not be established, and the other was that the IMV valve was corrected incorrectly.

The fault phenomenon is basically unable to start, even if it can start the fault light is still flashing. It is generally due to poor performance of the high-pressure pump.

Many people are replacing parts, resulting in high maintenance costs. Through discussion, let electronic control friends understand the possible causes of these failures, accurately judge and eliminate the failures.

Analyze as below:

IMV valve controller adjustment error (IMV valve adjustment current is too high) The larger the current, the smaller the opening of the IMV valve is, and the less oil is supplied to the oil rail, and vice versa. If the IMV valve adjustment current is too high, it is actually energized The current is higher than the design, or the actual opening is smaller than the design, so the actual fuel supply to the fuel rail is smaller than the design, but in the actual repair, when the fuel injector leaks too much, in order to ensure the necessary fuel rail Pressure, the opening of the IMV valve can only be larger than the design, and the energized current is smaller than the design to meet the needs. The fault code reported in this way should be: the IMV valve adjustment cut-off is too low instead of too high.

If such failures frequently occur, generally cold cars cannot be started with the starter. Whether you are a new battery or a new motor. However, it can be started with a cart. The normal operation after startup can be determined to be the problem of the injector.

IMV 1933.39

What does the IMV valve do?

The air compressor sometimes starts to leak air from the pressure relief valve or pressure relief solenoid valve when it stops when it is full, and then the air compressor starts to pump again, and so on.

The cause of this failure is a failure of the one-way valve. The function of the one-way valve is to only allow the air from the compressor to enter the air storage tank, while the air in the air storage tank cannot return to the compressor. The one-way valve fails. When the air compressor stops, the air in the air storage tank will be discharged through the pressure relief valve, causing the compressor to start repeatedly.

The one-way valve is located at the end of the compressor exhaust pipe near the gas tank.

Definition of IMV valve controller:

The IMV valve controller can be used with various regulating valves to display the upper and lower limits of the regulating valve stroke. If used in conjunction with a regulating system or an accident protection system, the valves in the regulating system can be interlocked. In the event of an accident, the stroke position of the regulating valve can be displayed. Therefore, the valve position controller is a valve position signalling device that drives the micro switch of the controller by adjusting the stroke of the valve and outputs an electric signal.

The working principle of the IMV valve controller: When the pneumatic actuator is working, the stroke changes, driving the rotating arm, the rotating shaft makes the cam rotate, the slider (adjustment block) on the cam touches the micro switch, and the lower limit circuit is connected, such as connecting a signal lamp or The alarm can display the lower limit position of the valve. Otherwise, the upper limit position is displayed. When used in conjunction with solenoid valves and relays in the protection system, the program can open or close the regulating valve for protection interlocking.

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HENSHINE PRECISION Machinery Co.,Ltd.was established in 2012,and it is high-tech enterprise which is professional diesel engine Valve and industrial hydraulic valve research,development,
Manufacturing and sales.Themain research direction:Diesel common rail suction control valve(SCV),




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