common rails test kit

Kroftools high pressure common rails test kit: How to use

Find out how you can use the KROFtools High Pressure Common Rails Test Kit.

Kroftools’ High Pressure Common Rails Test Kit is used to measure fuel pressure in any type of diesel vehicle equipped with the Common Rail injection system.

This kit contains flexible hoses that allow you to measure any CR injection system, up to 2000bar.

It also allows you to perform a series of tests so that you can make a quick and complete diagnosis on any CR system.

Learn about the 4 different tests in this kit and how you should proceed in each of them.


Test kit for Common Rails: procedures

1. Pressure test after start-up

The first test assesses the pressure after the start.

To do so, follow the following steps:

  1. Disconnect the metal tube between the pump and the CR;
  2. Connect the pressure gauge between the pump and the CR;


pressure test

pressure test-2


3. Start the car.

The pressure should remain around 300bar. Otherwise, something could be wrong with the fuel pump.

pressure test-3

The pressure should increase according to acceleration.

2. Injector test

injector test


If the engine does not start and there is a suspicion that an injector may be damaged, preventing the pump from reaching 300bar, it should test each one of the injectors:

  1. Unplug the injector that you suspect is damaged.
  2. Replace it with an injector spacer.

If you have replaced the damaged injector, the spacer will allow the pump to reach the 300bar – and the engine will start.

You should repeat this procedure with all injectors.

If all injectors are in good condition, the problem may be the fuel pump.




3. Maximum pressure test

maximum pressure test


There is also another test to measure the maximum pressure created by the fuel pump.
There are engines that cut the diesel feed on some pistons when the pump pressure is below 300bar.

To do this test follow the following steps:

  1. Connect the pressure gauge to the pump with a hose.
  2. Close the output of the pressure gauge with the cap;
  3. Turn on the diesel return tank.
  4. Try to start the car. The engine won’t start and no problem!

The pressure should reach 1050bar. If you don’t reach that value, there could be something wrong with the pump.


4. Pressure Regulator Test

pressure regulator test


In some cases, the problem is not of the pump, but of the throttle.
To see what’s going on, follow these steps:

  1. Connect the vehicle to a diagnostic machine.
  2. Collect some measurements for comparison.
  3. Turn off the vehicle machine.

These will be the measurements of the pressure regulator.

  1. Now remove the pressure regulator from the CR;
  2. Connect the appropriate throttle simulator, present in the KROFtoolsKit;
  3. Now repeat the start test with the pressure gauge.

These measurements will be the actual pressure values of the pump.

Therefore, if the values obtained on the diagnostic machine do not match, there may be something wrong with the pressure regulator.

As you can see, the KROFtools Common Rails Pressure Test Kit is very useful for a quick diagnosis of the common rail injection system, as it allows you to do several different tests.

Subscribe to our YouTube channel to browse videos about the latest KROFtools products and learn how to use them.

If you have any questions, do not hesitate to contact us.


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