Waveforms

Fuel injectors

Application:

  • single point injection;
  • multi-point injection;
  • direct injection.
Typical voltage waveform on the control pin of a fuel injector
Typical voltage waveform on the control pin of a fuel injector
Typical voltage waveform on the control pin of a fuel injector

Typical voltage waveform on the control pin of a fuel injector. The current waveform in the circuit is also shown.
1 – voltage on the control pin;
2 – current in the injector circuit;
A – start of the electrical injector pulse;
B – start of the actual fuel injection;
C – end of the electrical injector pulse;
D – end of the actual fuel injection;
A C – electrical injector pulse;
B D – actual fuel injection duration.

Voltage and current waveforms in a properly functioning fuel injector circuit.
Voltage and current waveforms in a properly functioning fuel injector circuit.

Voltage and current waveforms in a properly functioning fuel injector circuit.

Voltage and current waveforms of a malfunctioning injector
Voltage and current waveforms of a malfunctioning injector

Voltage and current waveforms of a malfunctioning injector. The injector pintle is sticking.
1 – voltage on control pin;
2 – current in the injector circuit.

Voltage waveform on the control pin of a peak and hold injector circuit sometimes used on low resistance fuel injectors
Voltage waveform on the control pin of a peak and hold injector circuit sometimes used on low resistance fuel injectors

Voltage waveform on the control pin of a peak and hold injector circuit sometimes used on low resistance fuel injectors used in single point injection or Throttle Body Injection. (Opel Vectra 1995 1.6).
A B – Peak phase where the pintle is forced to move;
B C – Hold phase where the pintle is held open.

Voltage waveform on the control pin of a peak and hold injector circuit sometimes used on low resistance fuel injectors
Voltage waveform on the control pin of a peak and hold injector circuit sometimes used on low resistance fuel injectors

Voltage waveform on the control pin of a peak and hold injector circuit sometimes used on low resistance fuel injectors used in single point injection or Throttle Body Injection. (Ford Orion 1.4 1993).
A B – Peak phase where the pintle is forced to move;
B C – Hold phase where the pintle is held open.

Voltage waveform on the control pin of a peak and hold injector circuit sometimes used on low resistance fuel injectors
Voltage waveform on the control pin of a peak and hold injector circuit sometimes used on low resistance fuel injectors

Voltage waveform on the control pin of a peak and hold injector circuit sometimes used on low resistance fuel injectors used in single point injection or Throttle Body Injection. Magneti Marelli (Peugeot 405 1994 1.6).
A B – Peak phase where the pintle is forced to move;
B C – Hold phase where the pintle is held open

Voltage and current waveforms in injector  circuit of a direct fuel injection system
Voltage and current waveforms in injector  circuit of a direct fuel injection system

Voltage and current waveforms in injector circuit of a direct fuel injection system.(VW Passat 1.8TSI 2008).
1 – current in the injector circuit;
3 – voltage on supply pin;
4 – voltage on control pin.
A B – peak phase when the pintle moves;

B C – hold phase where the pintle is held open.

Voltage and current waveforms in a Common Rail electromagnetic diesel injector circuit
Voltage and current waveforms in a Common Rail electromagnetic diesel injector circuit

Voltage and current waveforms in a Common Rail electromagnetic diesel injector circuit.
1 – current in the injector circuit;
3 – voltage on the supply pin;
4 – voltage on the control pin;
A B – peak phase when the pintle is moving;
B C – hold phase where the pintle is held open.

Voltage and current waveforms in a common rail piezoelectric diesel injector circuit
Voltage and current waveforms in a common rail piezoelectric diesel injector circuit
Voltage and current waveforms in a common rail piezoelectric diesel injector circuit

Voltage and current waveforms in a common rail piezoelectric diesel injector circuit (VW Touareg 3.0TDI 2005).
1 – current in the injector circuit;
3 – voltage on supply pin;
4 – voltage on control pin;
A B – injector opening;
C D – injector closing.