WS1 Petrol Fuel Injector Testing

Petrol Fuel Injector Testing 

I tested the injectors on a Toyota 4A-FE. I used a stethoscope to listen to the taping of the injectors. They sounded sharp how the supposed to sound. 

I checked the battery voltage when the engine was at idle and recorded 13.9 volts which is good. The injector voltage is as follows.

Cyl 1 = 13.8v

Cyl 2 = 13.8v

Cyl 3 = 13.8v

Cyl 4 = 13.8v

With the engine idling i hooked up an LED tester to the ground wire of the injector. All injectors worked.

With the engine still at idle i connected a multimeter and set to duty cycle. My readings below.

Cyl 1 = 98.7 %

Cyl 2 = 98.7%

Cyl 3 = 98.8%

Cyl 4 = 98.7%

Accelerating the engine slightly the readings changed 

Cyl 1 = 80%

Cyl 2 = 79%

Cyl 3 = 81%

Cyl 4 =  80%

Changing the multimeter to Hz and with the engine at idle i recorded the following.

Cyl 1 = .014 Hz

Cyl 2 = .015 Hz

Cyl 3 = .017 Hz

Cyl 4 = .015 Hz

Accelerating the engine slightly the readings changed 

Cyl 1 = .026 Hz

Cyl 2 =  .029 Hz

Cyl 3 = .028 Hz

Cyl 4 = .026 Hz

Using this formula {Pulse width ms = (% Duty cycle/100)/Frequency} i calculated the pulse width for each injector. 

Time at idle (ms):

Cyl 1 = 8.5

Cyl 2 = 8.4

Cyl 3 = 6.64

Cyl 4 = 7.53 

Time when Revved (ms):

Cyl 1 = 7.69

Cyl 2 = 7.5

Cyl 3 = 6.55

Cyl 4 = 7.64

In Conclusion i think pulse with is more accurate way to test injectors because we can see how long the are opening in seconds, much easier to see rather than using Duty cycle or HZ.