Air flow meter and injectors

[msgsupra84]

So I was working on my car today and I was messing with the afm. Everytime I opened the flap, I could hear the injectors pulsing. My fuel pump is on a toggle switch (basically replacing the fuse relay in the box with wires, inline fuse, and a switch) wire is going from the battery, inside the car to the switch, and back out to where the relay goes. Anyways I had the switch on and my key on with the car off and the injectors pulsed when I moved the flap, is that normal? I'm not worried if it is but if it's not then I need to start pulling and checking the harness.

['82supra]

Sounds like you've got the fuel pump hardwired bypassing the ignition, so it wouldn't actually be 'normal', but it sounds like the afm is working as it should.

[FranK]

Your injectors can't pulse if the engine is not in rotation. Because it's your ECU who's calling the shots on your injectors and he need a signal of rotation from the engine to do this.

[StanS]

^ Agreed. If you don't believe Frank then pull a plug and see if you smell gas when you think that your injectors are firing.

[msgsupra84]

Well it sounds like injectors, and you would think that since my fuel pump and all is hotwired then there is a possibility they are pulsing. Not saying youre wrong, just putting my thoughts out. Cause I have wiring issues in the fuel system and didnt know if that was normal.

[ma67 lover]

1 why did you hard wire your fuel pump? two it might be your relay for your fuel pump

[FranK]

If you have wiring problems, you don't have a lot of choices.

1. Short circuit --> fuses blown

2. Open circuit --> Ecu telling bad sensor, or components not working at all.

Probably you're hearing the Circuit open relay activating when you push the plate inside the AFM.

['82supra]

Does your car run? What were you working on? As for switches, should be no prob on a fuel pump, added anti-theft device.

[StanS]

fp operating and injectors firing = gas in cylinder if engine operates regardless of what you think