Fuel Injectors

Fuel Injectors 

The fuel injector is a solenoid device that is supplied a high voltage supply circuit and a high voltage control circuit from the ECM. Electrical pulses are supplied by the ECM to each fuel injector at the correct time and sequence determined by information received from the camshaft position sensor. When the fuel injector receives electrical pulses, fuel is sprayed from the fuel injector tip directly into the combustion chamber on the compression stroke of the engine. The fuel injectors are located above each cylinder and deliver fuel directly into the cylinder. Each injector has a high pressure fuel pipe from the fuel rail and a return line.

Small Quantity Adjustment (SQA) 

The Small Quantity Adjustment algorithm is an engine control system function aimed to maintain acceptable noise and emission levels during vehicle lifetime by means of adjustment of the injected fuel pilot quantity. SQA purpose is the adjustment of injector to injector deviation, to recover the drift caused by the mileage accumulation, acting on the energizing time of each injector in the Small Quantity Area. This algorithm can be implemented taking in consideration as feedback the crank-wheel response (SQC - Small Quantity adjustment based on Crank-wheel sensor).

Small Quantity Adjustment Based on Crankshaft Position Sensor Functionality (SQC) 

Small Quantity Adjustment based on crankshaft position sensor functionality is a strategy able to compensate injector drift due to aging in small fuel quantity area. This strategy runs during Deceleration Fuel Cut-Off by energizing each injector in order to inject a small test quantity and checks the crankshaft position sensor response (angular acceleration produced during the combustion phase).