Does Polarity matter on a peak and hold fuel injector?
 

I found one of my injector connectors wired opposite of the other three w r t polarity.
I would think this would matter if the injectors have a coil wrapped around a magnetic core also known as a solenoid.


But everywhere I look, people say that the injector wiring polarity is irrelevant.

If we are dealing with an electromagnetic field inducing movement inside the injector, how can it not matter which end of the internal coil is 12V and which one is pulsed to ground by the PCM/Ign circuit?
Wouldn't it induce movement in the opposite direction?

The only explanation I can think of is some sort of internal rectification between the terminals and the moving parts. Or a funky variation of a solenoid design

A little help?

Thanks

I have electro magnet solenoids on most of my trucks. The magnets do not care which wire is + and which is -. It just induces the magnet which moves the pin. Polarity might change timing like it does in a moving pole generator like a distributor coil.

Even though I have no idea what the hell you're talking about, I'd make it match the other 3. Part of my OCD side, I guess.

A good question, one I had never thought about. My understanding after a little research is that the electronic fuel injector does indeed use a magnetic coil to actuate the plunger, which allows fuel under pressure to flow through the nozzles. But, unlike a solenoid, which has a fixed core in the magnetic coil, the plunger is free to move into and out of the coil. The plunger itself is not magnetic, it only responds to the magnetic field created by the coil. Changing the polarity of the coil does change the N/S poles of the coil, but because the plunger is not magnetic it is not attracted/repelled by the coil, merely drawn into the created magnetic field.

It does seem strange though that the wiring on the connectors is not consistent. When troubleshooting, it helps if things are done the same way 'across the board' so you don't have to guess where the constant power is vs the ECM controlled ground.

Thanks folks.

I am used to the good pld "right hand rule." I still don't get how current through a coil wrapped around a magnetic core can not care which way the current runs -- seems like it should change the direction of trave of whatever is in the mag field.

But I fully accept your answer as one more knowledgeable than I.

Which is why I asked ;)