My attempt at 100K maintenance

So changed the transfer case and rear diff this morning. Went by pretty smooth. So I decided to keep going with the 100K maintenance and decided to tackle the spark plugs. This is where the problem lays. Did the passenger side first since I've heard its the hardest and then the driver side. Got everything buttoned up thought everything went smooth, other then the 2 rear plugs on each side are a pain. Took it for a drive in the neighborhood and truck was sputtering and the check engine light come on. So Im guessing one or more aren't in all the way or correctly and they are misfiring, Im not 100% sure as this is my first attempt at changing spark plugs.

Any insight or guidance will be greatly appreciated.

 

Make sure the coil pack is fully seated and the connector for the coil pack is seated as well.

 

You sure you have the right plugs?

you need to see what codes are being thrown. Maybe a coil pack didn’t get plugged in all the way? Not sure how you could have a plug “not in all the way”.

 

I bought OEM spark plugs. I guess I will drive it up to Oreilys in the morning and see what code is being thrown. Driving it won't mess anything up will it?

 

Okay so maybe before going up to see what code is being thrown, unscrew and pull out and reinstall the coil packs? The first 3 on the driver side did float a little and I pushed them down when I was threading the screw. Maybe its a simple fix.

 

Did you buy the OEM spark plugs from E-bay or Amazon?
https://www.youtube.com/watch?v=pIMZRgR8fc8

 

You check gaps on plugs?

 

I bought them from an auto parts store

 

I did not. What is that exactly?

 

This is the best 1 minute explanation I could find. Most new spark plugs will need a small adjustment before install. This may not be your issue, but it needs to done either way for your truck to run properly. Unfortunately, you will need to pull them all, gap them, and re-install.
https://youtu.be/v5EzZ2dtd4o?si=IZBVJ4RJsjeMPC0s

 

Here is the gap measurement. I prefer the wire style gapper vs the style shown in the video. Less guessing. Just make sure it has a wire size within the measurements spec'd in the book. Also, hand tight on these puppies, don't go crazy. You should be able to seat the spark plug almost all the way using just the socket extension with no ratchet. This will also avoid cross-threading. Then give it a soft snug with the ratchet. I think torque is around 12 lbs, which is equivalent to wrist tight with a screwdriver. You have a lot more leverage with a ratchet, so be careful

 

When I did mine I really had to give the coil a decent push for it to click in. The rears are harder just because of the awkward angle you are at due to the hood props.

Another good thing to do is add some dielectric grease to the coil to prevent arcing. Not entirely necessary though.

 

UPDATE:

Okay so this morning gapped all spark plugs. The driver side set were really off. The second go round took about 1/4 the amount of time the first round did. Gave the boots/coil a decent push and twist. The engine didn't sputter any more but the engine light was still on. Drove it to OReiley and had them plug in to see what code was being thrown. P0303. Cylinder 3 Misfire. Suggested part: replace the ignition coil. So I did that in the parking lot and erased the code. Truck is running good now. I am pretty happy that I was able to get it taken care of.

Thank you to everyone that responded and gave advice.

Edsel

 

Next going to tackle the power steering, coolant and brake fluid. Ordered a pump for the power steering and brake fluid.

Lastly the transmission fluid drain and fill. Doing it once then drive 10K and doing it again. I'm at 103K miles and it's the first transmission maintenance done. The transmission fluid maintenance still intimidates me because of having to make sure the temp is correct.

 

I highly advise getting a scan tool if you plan on working on the vehicle yourself. It helps so much. Use some of the money you save on labor to get one. Not necessary but damn useful. I have one permanently installed in the FJ and recently grabbed a xtools computer to use anywhere

 

Suggestions?

 

Probably didn’t need to replace the coil pack, code was left over from when the OE coil pack wasn’t properly seated.

 

I was thinking the same thing. Hopefully he kept the old coil. Might come in handy as a spare if he can verify that its ok.

 

Dang. Didn't think of that. I do still have the coil. Maybe I'll put it back on and see if it still throws the code. Would save me $100.

 

They won’t take the new one back if it’s been installed but will make a good spare.

 

This is the one I got. It was on a lightning deal and I paid $269 for it. I know there are cheaper options as well but a few of my friends have this one and it does a lot of stuff.

 

I had an injector fail on the FJ. Having the computer made the process real quick to identify. I ended up replacing all the plugs and injectors while I was in there. When I first searched online what the cause could be the reply’s scared the hell out of me. Turned out it was a 3 beer job and she purrs again.

 

Parts store coil packs are junk. Stick the original back on and either try and return new or keep as a spare.

 

So you plug that in and it let's you know what code is being thrown?

 

This is more useful than that. You can do all kinds of stuff with it. From scans to programming key fobs. It gives you live data and graphs so you can really see what’s going on.

 

Parts stores do sell Denso which is good to go.