fuel injectors get constant fire
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8th Gear
Joined: Oct 2006
Posts: 8
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fuel injectors get constant fire
I checked both wires going into the injector with a voltmeter. They show a constant 10 (I think volts, not sure with my old meter) with just the switch on. The meter also stays the same as you turn the engine over. The LS1 is in an old 51 International Pickup so it has a hot rod harness that does not have a access port. Local sources tell me the voltage does fire from ground, but only should flicker when the cylinder fires. They say the problem is possibly the crank sensor or the cam sensor. I was hoping someone here could help. Thanks Rick
Cruising
Joined: May 2007
Posts: 13
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From: Birmingham AL
Never tried to do it but you should read voltage on both sides of the injector. If you didn't you would have a burned up or "open" injector. The injector coil is just a winding of fine wire and the voltage is going to pass through it although it should drop on the ground side because of resistance. The only way you would read no voltage on the ground side of the injector is if this side was truly grounded, then you'd drop all the voltage across the injector and get battery voltage on one side and nothing on the other. When the engine is off there is no ground path so you should read voltage on both sides, just a lower voltage on the ground (or PCM) side. If you want to test the injector leads to see if they are firing you need a "noid" light. You pull an injector connector and plug the noid light into it. It will flash when you crank the engine over if the PCM is doing it's job. You can make one for a few dollars from an LED and a resistor from Rat Shack.
Good luck, Michael
Good luck, Michael
