I think this forum is better for technical advice, instead of posting in my performance thread.
I'm having an injector issue on cylinder #3. Sometimes the car misfires, and sometimes it runs smooth as glass. There seems to be no pattern behind the symptoms.
Bill Buttermore helped me diagnose it today. Using a rubber hose as a stethoscope, we determined that when it misfires there is no pulse in the #3 injector. We swapped in a used injector from the junkyard, but there was still no pulse. Resistance was the same on all injectors, including the junkyard piece. We did not have a test light to check power to the injector, but Bill put a voltmeter on a few sets of the injector wires and got a reading of 13 volts
. Not exactly sure what that meant. So we put the original injector back on, I started to leave with the motor misfiring like crazy, and before I got to the end of the street it was running smooth again.
I don't think it'* fixed, because it has been running so erratically all week. I'm going to get a test light to check for power to the injector the next time it misfires. What could be causing this? The injector has to be decent if it runs smooth from time to time..... so what could be the cause of an intermittent injector failure? Bad wiring? Bad injector driver in the PCM? Whatever it is, when it'* good it stays good for a while, and when it'* bad it stays bad for a while. Very mysterious.