Misfires cyl 3 & 4 4runner

[BD7]

1996 Toyota 4runner 3.4l 5vz-fe

My brothers 4runner was running rough lately. I pulled the following codes with the scanner.

P0300 Random, Multiple Cylinder Misfire Detected
P0303 Misfire Detected in #3 Cylinder
P0304 Misfire Detected in #4 Cylinder

On this motor, there are coilpacks on the cylinders 1, 3, 5. Then there are wires on cylinders 2, 4, 6 thats connected the coilpacks.

Spark plugs were change a year so I doubt thats the issue. I was going to say coilpacks, but if coilpack #3 is bad, shouldnt get I get a misfire code for cyl #6 too?

Topic

[dave]

The $10,000 dollar question would be what brand of spark plugs did you put into your Toyota.. :whistle:

[BD7]

I always stick with OEM when it comes to spark plugs. In this case, I remembered its NGK.

[John B Kobberstad]

Is it a constant or intermittent misfire? Are you getting spark to 3 & 4? Fuel to 3 & 4?

[dreamer2355]

I would be checking for spark on each of those cylinders by using a ignition tester. The adjustable testers work better so you can stress test the ignition system seeing as they tend to fail under a load.

Id also be doing other basic tests such as checking your injector pulse.

Keep us posted.

[college man]

try doing a power balance test.

[EricTheCarGuy]

You can’t take the cylinder #’s in a misfire test as law as they are not often correct. That said with a misfire a good place to start is with a power balance test as shown in the video above. This test will help you identify if a cylinder isn’t firing as good as the rest. Given your ignition set up I would suggest pulling the connectors off of the injectors one at a time instead of using the ignition to cancel the cylinders. If you determine the effected cylinders the next step is to find out if the misfire is the result of an ignition problem, a fuel problem, or a mechanical issue. First lets see if we can find the problem cylinders.

[Author]

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