EFI power

Another thing you want to check "in general" if you still have an 3 or multi wire alternator / regulator setup and not a "1 wire"

That is to check your running/ charging battery voltage. Once the battery/ engine is warmed up and the battery "normalized" be sure charging voltage at simulated "low to medium cruise" RPM is not more than a bout 15. "Normal is 13.8--14.2. If this is high you likely have voltage drop in the "ignition run" circuit. You can check this by putting one probe of your meter on battery + directly, the other probe on your ignition "run" in the engine bay, and turn the key to "run." You are hoping for a very low reading, the lower the better

More than say .3V (3/10) I would check the path back to the battery. Also be certain the VR is well grounded, and has a good ground path to battery NEG