#3 intermittent misfire-help

[beige97camry]

car been running fine, new plugs, wire resistance good, check engine lite came on and auto zone tester said intermitent misfire on #3, disconnected battery and changed plug, light out but still putters and gets bad mileage. any ideas??? how do you test the coils on the 4cy camrys??? how do you test the fuel injectors??? plugs are platinum (5K on them) and look very clean. thanks

[Mike Gerber]

You will have to look in the manual for the procedure for testing the coil and the fuel to that cylinder. However, since it is only that cylinder that is missfiring, (instead of random missfiring on all cylinders), the first thing I would do is to pull that #3 spark plug wire and check it. First, make sure that the wire is seated properly on that plug. Check for oil on the plug end of that wire. Then check the resistance of that wire with a digital volt/ohmeter. Don't be surprised if you can't get a reading, meaning there is a break in that wire some where. Also check where that wire seats on the coil. There may be some corrosion there. These simple problems are much more common than coil problems itself and fuel injector problems.

My hunch is simply a bad plug wire.

Mike