Diesel injector nozzle calibration is necessary when your car is an old model which had been used for decades because parts have passed through heat over time and may have weakened, or have perforations.
This service is also needed in modern cars which are digitally equipped but may have encountered fault in a program that feeds the wrong message to parts that perform the measurement of the right amount of fuel for the engine.
Why calibrate injectors?
A fuel injector is an assembly or group of parts assembled and otherwise called a nozzle. Sometimes the whole thing is called nozzle and the end part of the injector where the fuel comes out is also called nozzle.
The function of the injector is to control the flow of fuel through the injection nozzle to the combustion chamber.
On the passage of time, one of the parts may have weakened or had perforations and for that reason, the right amount of fuel to be supplied to each cylinder is no longer normal causing more emission of smoke undesirably affecting anyone around.
The primary reason why injectors are calibrated is to bring it back to the original pressure that supplies the right amount of fuel to the cylinder for efficient performance.
How is Calibration Done?
This should be done by professional technician unless you have the devices to use and you know the proper pressure.
The reason is that calibration is not just cleaning the injectors but it is to check the pressure and if it is not in the desired one it should be put back to the original pressures.
Why has the pressure possibly changed? There are two reasons that contribute to this state, the nozzle spring and the injection nozzle.
As I have said there are parts that may in due time weakens or perforated because of heat.
If the nozzle spring has weakened the pressure has loosened and more fuel is sprayed to the cylinder. The remedy is to change the shims to a thicker to add pressure to the spring.
If there are perforations on the nozzle or the nozzle needle there is no other remedy than to replace the injector. You cannot control the flow of the fuel by adding shims to add pressure to the spring.
Disassembled Diesel Injector
Possible Symptoms when Diesel Injector needs calibration
Black smoke-this is a sign that fuel is over to the limit needed by the engine for combustion. Not all fuel is being burned and so it is wasted and emitted outside. If smoke is white oil is passing somewhere the cylinder or cylinder head gasket and is mixed with the fuel in the combustion chamber.
The Nozzle Tested on a Pressure Guage of 125 Pounds Per Square Inch (PSI)
Rough Engine Idle
Assuming that you have fixed all the proper idle speed, no vacuum leaks, no damaged or incorrect spark plug gaps (for the four-stroke engines), you have calibrated your fuel injection pump but the idle is still rough it’s time for you to have your fuel injector calibrated.