Howdy everyone, I hope you're having a fine day.

I've got a 2000 Tracker with a rebuilt 2.0L and now that the spark plugs are finally firing, the fuel injectors won't. I checked the coupler that hooks up to the fuel injector harness and it's receiving a weak signal. Any ideas?

Define "weak signal" - if I remember correctly one side of the injectors are connected to +12V and the other is pulled to ground by the ECU - do you have a good +12V feed?

Define "weak signal" - if I remember correctly one side of the injectors are connected to +12V and the other is pulled to ground by the ECU - do you have a good +12V feed?

No, it's significantly lower

Well - you know where to start looking...

The injectors are powered directly off of the fuel injection system main relay which get's it's power directly off of the fuel injection fuse - sounds like you have a bad connection somewhere.