WS1

WS1Petrol Fuel Injector Testing

Injector Pulse Time ON/OFF 

First we tested the injector using the Oscilloscope to see the waveform showing the injector pulse open and closed.  At one cylinder  we can see the injector's duty cycle at the engine idle.

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We also measure the injector voltage  with the Ignition Off, Ignition On, and  engine idle. One other test is using a screwdriver, attach on top of the injector and check for click sound as the injector is open and closed.

Record battery voltage 13.54v

Injector voltages Test:

Cyl #1	Cyl #2	Cyl #3	Cyl #4
12.00volts	13.00volts	13.00volts	12.00volts	Volts

In the engine idle, the injector firing indicates by the LED tester, As the injector is ground by the ECM to fire, the test light also grounded showing on the video the LEDs flashing as the injector pulse open and closed.

  

LED tester

Cyl #1	Cyl #2	Cyl #3	Cyl #4
Ok	Ok	Ok	Ok	Tick if flashes

Engine at Idling (In Duty Cycle %)

With engine idling, we record the injectors firing by using a multi-meter set to read % (duty cycle). Showing each injectors operate at 98.6% (duty cycle)

Cyl #1	Cyl #2	Cyl #3	Cyl #4
98.6%	98.6%	98.6%	98.6%	Duty Cycle %

Again with the multi-meter still set to read % (duty cycle), we accelerate the engine short and fast throttle opening. This would give us maximum % reading and the RPM.

Accelerate engine (Duty Cycle %)

Cyl #1	Cyl #2	Cyl #3	Cyl #4
64.1%	87.1%	60.1%	68.8%	Duty cycle

Here we set the multi-meter to read Hz, and with the engine idling, It showing the time of each injector

Engine Idling (Hz)

Cyl #1	Cyl #2	Cyl #3	Cyl #4
12Hz	12Hz	13Hz	13Hz	Hz

With the multi-meter still set to read Hz, we increase the engine RPM and watch the Hz changes rabidly increase. The highest reading from each cylinder is recorded.

RPM Increase (Hz)

Cyl #1	Cyl #2	Cyl #3	Cyl #4
36Hz	36Hz	42Hz	48Hz	Hz

Formula calculate

 “Pulse width ms= (% Duty cycle x100)/Frequency”

 Engine idle:

 Cyl1)    98.6% / 100/12Hz = 0.0821ms

Cyl2)    98.6% / 100 / 12Hz = 0.0821ms

Cyl3)    98.6% / 100 / 13Hz = 0.0758 ms

Cyl4)    98.6% / 100 / 13Hz = 0.0758 ms

Acceleration (revved up):

Cyl1)    64.1% / 100 / 36Hz = 0.0178ms

Cyl2)    87.1% / 100 / 36Hz = 0.0241ms

Cyl3)    60.1% / 100 / 42Hz = 0.01430ms

Cyl4)    68.8% / 100 / 48Hz = 0.01433ms