​Remanufacturing of Bosch unit injectors

​The repair process for unit injectors consists of several stages:
Stage I

- Chemical cleaning

- Test on EPS EVO1

Stage II

- Dismantling the unit into its component parts

- Visual assessment under a microscope

- Mechanical inspection: tip grunt, memory unit test, etc.

- Opening pressure test

Stage III

- Replacement of damaged and worn parts

- Mechanical re-examination

- Setting the opening pressure

Stage IV

- Performance test (power measurement)

- Simulator test, measurement of corrections, BIP test

​Decrease in engine power: If the engine does not generate the same power as before, this may be due to inefficient fuel injection through faulty unit injectors.

Starting difficulties: Engine starting problems, especially in cold weather, may indicate a malfunctioning unit injector.

Uneven engine running: Uneven running, rev waviness at idle or jerking while driving can be the result of incorrect fuel injection.

Increased fuel consumption: Defective unit injectors can deliver too much or too little fuel to the cylinders, leading to increased fuel consumption.

Smoke from the tailpipe: Excessive smoke emissions, particularly black smoke (excess fuel) or white smoke (insufficient combustion), can indicate problems with the unit injectors.

OBD diagnostic system errors: Modern vehicles can register errors related to the injection system. Connecting a diagnostic device can help identify unit injector problems.

Engine vibrations: Malfunctioning unit injectors can cause engine vibration, particularly noticeable when driving at low speeds.

Increased engine operating noise: A defective unit injector mechanism can cause increased engine noise, which is particularly noticeable during acceleration.

​When remanufactured professionally, using original spare parts and following the manufacturer's recommendations, remanufactured unit injectors can achieve a service life comparable to new parts. This means that they can function properly for tens of thousands of kilometres - in some cases, drivers report trouble-free operation of 100,000 km or more. However, as with new parts, the actual service life will depend on driving style, fuel quality, regularity of oil and filter changes and the overall condition of the vehicle.

It is important to remember that regular servicing and proper vehicle operation are key to maximising the life of remanufactured injectors. This includes avoiding extreme loads just after starting the engine, when the oil has not yet reached its optimum temperature and viscosity, and ensuring that the engine regularly reaches operating temperature, which helps to remove accumulated dirt and moisture from the fuel system.