Where do my injectors get their ground?

How can I test if they spit?

If I unplug an injector, is there a way I can connect a light on the conector to see if I have electricity?

I have low impedance injectors for sure, how do I know if I have the right wire harness? I'm pretty sure I have the right one since all injector plugs are on-center plugs just like my injectors.

 

Power is supplied to the injectors when the key is on and ground is applied from the control unit to fire the injectors. The amount of fuel injected depends on how long (in milliseconds) the control unit grounds the injectors. If you were to use a 12V test light, when you unplug an injector connector and turn the key on and engine off, the test light should light on one terminal. If you were to "backprobe" the connector with it still plugged in to the injector, your test light should light on both connector wires (the injector is a coil). This tests for available power only. To check for injector pulse when cranking, unplug an injector and use your test light. Use a paper clip attached to your test light's ground clip and touch it to either injector plug terminal. Touch the test light probe to the other terminal. Have someone crank the engine over. You should see the test light flash on and off as the engine turns over. If not, the control unit is either not properly grounded, has a bad injector driver, or is not getting an input signal.

 

1- Where is/are the grounds? One on the engine, one behin the dash and a last one in front of the front right tower, right?

2-The only way to fix a driver problem is to change eccus?

3-not getting an input signal? Why would that be?

Thanks!

 

www.aaroncake.net has a good write up for regrounding all the grounds.

 

They are grounded by the ECU to fire them. One side connects to 12V when the key is turned to IGN, and the ECU switches the other side to ground to fire the injector.

Pull the fuel rail and secure the injectors in place outside the engine. Then disable ignition by disconnecting both coils and crank the car. The primaries should fire.

Connect a low wattage 12V bulb directly in place of the injector. The pulsewidths may be too small to light the bulb so this is best done with a scope.

Why would you have the wrong harness?

Low impedance cars have a resistor block under the AFM.

 

I dont have a resistro pack under the AFM.

I was told that if you have on center plugs, its a low impedance harness, if its off-center plugs, its high impedance. Is thta true?

Is the resistor pack plugged into the harness or wired in?

And by AFM you mean air flow meter, right?

 

Generally, yes.

It plugs into the emissions harness.

Yes.

 

How do I know if I need the resistor pack?

What happens if I use high impedance on low impedance injectors?