2004 Ranger Cylinder 4 misfire

[Willard]

Thanks, I will definitely give it a clean and see what happens. I should not I tested the coil pack and the resistance checked out fine. I'm still kind of suspicious about the wires as well, I will take a look at them once it gets dark and see if there is any arching going on.

[Willard]

Well I may have found the issue. I finally remembered to go out and have a look with it nice and dark outside, and sure enough, I got arcing going on with that number 4 wire. It looks like a bad connection down towards the plug, that's where most of the action was. It also shot some random arcs on the other side where that wire goes around the back of the motor. I also some a little arcing on the number 1 and 2 plugs.

Also, I revved it up while I was watching, and the arcing actually went away mostly, which explains a lot. Remember this wire tested out at less than 10k ohms resistance, which should be pretty good. Definitely didn't tell the whole story though. Whenever I get paid I will grab a set of Autolite wires and throw them on to see what happens.

Edit: Went and looked some more, is it normal at all to have arcing right at the end of the boot where the wire goes over the plug? I ask because cylinders 4,5, and 6 all had a bunch of arcing at the actual spark plug like that. The more I watched it the worse it got on #4, too. It was shooting all the way up the wire almost. Cylinder 2 had a pretty nasty one too.

[Runnin'OnEmpty]

Originally Posted by Willard

.........
Edit: Went and looked some more, is it normal at all to have arcing right at the end of the boot where the wire goes over the plug? I ask because cylinders 4,5, and 6 all had a bunch of arcing at the actual spark plug like that. The more I watched it the worse it got on #4, too. It was shooting all the way up the wire almost. Cylinder 2 had a pretty nasty one too.

No, that is not normal. There should be no arcing at all!

I'm sure you've found the problem and it should run
like a champ with new plug wires.

[Willard]

I'm pretty confident I found the issue as well. I can't wait to get money to put some new plug wires on this thing, hopefully it helps the gas mileage on it. I've been averaging 16.5 with quite a bit of highway, and I would like to see better with this truck

[Willard]

Well, got the new wires today and installed them and did a seafoam treatment while I was at it.

It definitely runs better, and after a good long drive I got back and let it idle for a few minutes, and no misfire

It still isn't a perfectly smooth idle, but I think it's probably as good as a 3.0L will get. The torque seems to be better, I noticed it downshifted less on the hills, and it seemed to climb better overall. So I'm gonna hope I've got this kicked, and now its time to save up for some power adders for this little motor

[Runnin'OnEmpty]

Good job!

Cool Ranger.