1995 Isuzu Rodeo Repair Question
First, the way they checked it works. However, it doesn't tell them the injector is bad. It could be low compression in that cylinder, a bad spark plug, a bad plug wire, or a bad injector. Check all of the items I mentioned. Make sure the new plug was properly gapped and sparking. Also, make sure the compression is good. Next, you need to get a noid light. Most parts stores will lend them to you. Unplug the injector and plug the light in to the power side of the wiring. Start the engine. The light should flash every time the injector gets power. If there is no flash, you need to check the wiring back to the PCM to see if there is an issue there. Also, each injector has its own driver in the PCM, so if there is no wiring issue, the PCM becomes a suspect. If you do have a pulse, remove the injector to check if it is spraying.
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