Fuel injector

JASON WIL

MEMBER
1995 ISUZU RODEO
6 CYL
134,000 MILES

My 95.5 Isuzu Rodeo with a 3.2 v6 is running rough and shakes while in park and shakes while you drive it. I replaced the sparkplugs and checked the wires, the ones that run from the coil to the sparkplug. They all tested good on the oms, I test the oms on the coil and the primary and secondary was in standards. I took it to the shop and they said it was a bad injector, with is the number 5 cylender, they did this by removing the sparkplug wire and hear no differenc in the motor idel. Do you think this is what is causing the problem and also how do you test the fuel injector to see if it is performing correctly. Thanks any help would be good

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,724 POSTS

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.