Dual Patterns (WS3B)

MAP against Injectors

When there is less vacuum the map signal voltage gets high telling the ecu that there is more air pressure in the engine, the ecu then grounds the injector longer so that it sprays more fuel to compensate with more air coming in the engine.When map signal voltage gets low the injectors is grounded for a short time. So When the output signal voltage for map increases the injector gets grounded longer.

Oxygen Sensor against Injectors

As we increased the rev on the engine the injector was feting grounded for longer and output signal of the oxygen sensor went high telling telling the ecu that the fuel mixture is rich.When the oxygen sensor detects less oxygen in the exhaust it sends out out a high signal of 0.9v telling the ecu that the engine is running rich. Then the ecu will decrease the time the injectors are grounded to make the fuel mixture leaner. When the oxygen sensor sends out a low voltage of 0.2V it will tell the ecu that the engine is running lean so the ecu will ground the injectors longer so it sprays more fuel to get the mixture rich. The oxygen sensor cycles from rich to lean to control emissions and to keep the fuel mixture stoichiometric , doing this the injector is open longer to make the fuel mixture rich and open less to make the fuel mixture lean.

RPM distributor against Injectors

As the engine rpm increases the RPM signal frequency increases therefore dwell time and firing time of the coil is faster. So the spark is comes on faster. When engine RPM increases it needs more fuel so the injector gets grounded longer giving out more fuel as the engine is sucking in more air. When the engine is decelerating the RPM signal decreases therefore the injection time gets less. The RPM signal gives signals to the ecu and the ecu then control the injection time.

Injector Voltage and Injector current

1 - current is not flowing.

2 - current increases in the winding of the injector and the longer the injectors are open the higher the current gets higher.

3 - injector closed and open circuit so the current goes down to 0.injector ungrounded so current is not flowing.

A - battery voltage at injector

B - Injector is grounded.

C - injector is grounded therefore is open and spraying fuel.

D - Injector closes therefore a voltage spike of 50V.

E - voltage gets back down to battery voltage.

When the injectors open current starts flowing and slowly increases when is kept open and then goes down when it closes.

Ignition Primary Voltage against Ignition primary current

When the coil gets grounded the current builds up slowly and then hold the current to 6amps. As soon as the coil is ungrounded the the magnetic field collapses therefore the current goes down 0 and voltage spikes up to 300 v in the coil. So when the coil is grounded a magnetic field is created in the windings so the current  build up and stays in the windings until it the coil is ungrounded for the firing voltage. Thats why the coil gets hot when power is supplied though it for long.