DLLA152P847 Common Rail Diesel /Fuel Injector BOSCH Injector Nozzle

INJECTION NOZZLE FAULTY: SYMPTOMS

If an injection valve is faulty or not working properly, it can cause the following fault symptoms:

• Problems starting
• Increased fuel consumption
• Loss of power
• Fluctuating idle speed
• Poor exhaust emission performance (e.g. emissions test readings)

Potential consequential damage:

• Shorter engine service life
• Damage to the catalytic converter and diesel particulate filter
• CAUSES OF FAULTY INJECTION NOZZLES: CAUSE OF FAILURE
• IF THE INJECTION VALVE IS FAULTY OR HAS REDUCED FUNCTIONALITY, THE CAUSE MAY BE:
• A blocked filter screen in the injection valve as a result of contaminated fuel
• A poorly closing needle valve caused by tiny dirt particles from the inside, combustion residue from the outside, additive deposits
• A clogged, closed outflow bore hole
• A short circuit in the coil
• A cable break to the control unit

CHECKING INJECTION NOZZLES: TROUBLESHOOTING

• Troubleshooting can be performed both when the engine is running and when it has been switched off.

Troubleshooting when the engine is running

Compare the injected fuel quantity

Using a cylinder comparison measurement and simultaneous exhaust measurement, the injected fuel quantity can be compared based on the drop in speed and the HC and CO values for the individual cylinders.  In the best case, the values will be identical for all cylinders.  If there are major deviations between the values, it may be that not enough fuel is being injected (a large quantity of unburnt fuel = high HC and CO values, whereas little unburnt fuel = low HC and CO values).  The cause may be a faulty injection valve.