Make sure all the grounds on the engine are clean and good ( no corrosion ). Especialy the one that feeds the ECM. A ground can get OVER LOADED just like a hot wire. A corroded ground will over load the circuit.
You are correct, the ECM controls the ground. There is voltage to the injector all the time--even if the engine is not running--as long as the key is on.
Did you test for spark? Did you test the injector with a NOID light? Like I suggested?
Monday, March 31st, 2008 AT 5:12 PM