Instructions: 1. Remove the return line clip from the injector. 2. Gently pull the return line, including the plastic adapter, from the injector. 3. Select the appropriate adapter. The pre-assembled adapters on the hose are suitable for Bosch injectors. 4. Mount the hook of the aluminum measuring cup holder, e.g., on the engine hood and connect the tubes or measuring cylinder to the injectors; you must mount the original clip so it can fall off. 5. To obtain a meaningful result, connect a measuring cylinder or measuring cup to each injector. For example, a 6-cylinder engine must also be connected to 6 measuring cylinders or a measuring cup. 6. Start the engine and let it idle. 7. Refer to the graduated cylinder or measuring cup; as soon as the engine is running, they must be filled with fuel from the common rail system. 8. Stop the engine if a significant difference in quantity or the maximum quantity is reached. 9. The difference in fuel quantity between the cylinders gives you