First post:tune up, etc

This is my first post so I just want to say what's up to you guys before I start yapping, and forgive me if my questions are dumb.

I plan on doing a tune up on my 2000xj sport on Thursday, and I like for things to go as smoothly as possible, but I'm not quite sure how it's all set up. Am I correct in saying that I have no distributor, but still have wires, cap rotor and 3 coils on my 4.0?

My check engine light came on after only having this vehicle for less than 4k miles, and the code it gave was: cylinder 6 misfire. Do I have to replace the coil just for that cylinder or all of them; if my assumption above is correct?

Also are there any tips or tricks of a basic tune up I should be aware of before this venture? I plan on changing o2 sensor, using NGK copper plugs, with taylor custom fit wires. What gap should I use with these plugs?

A little history of my xj: I bought this from a dealer used w/49k miles on it. I don't think it's ever been tuned up and whoever owned it before me didn't care much for taking exceptional care of their vehicles like I do. But it's straight and runs good w/no accidents which is all I really cared about. I previously owned a 1990 xj 2dr with a 5" lift and 165k miles which still ran great(I should not have gotten rid of it!)

I also recently changed my oil to mobil1 full synthetic--was this a good or bad idea not knowing the previous mechanical history of the vehicle?

Last inquiry-The paint is in good shape except for a few things. Water spots are everywhere on this thing; on the windows and in the paint. Is there a way to get rid of them? And there is a small rust spot on the roof, where the paint came off also; how do i get rid of it and keep it from spreading?

Thanks to anyone and everyone in advance for your responses.

P.S.-I did use the search and found a few answers to other questions

I,ll try to answer a few of your Questions,however my reference only goes to the 99,s.And I have limited reference to the 00,s.
Plugs -I have always used champions,they are OE equipment and have worked fine for me.
Plug wires--you don,t have any
Distributor cap-you don,t have one
Coils-you have 3-one each for cylinders 1-6,2-5,3-4. If the problem only happened once,I wouldn,t worry
Oil-as new as the engine was ,you did a good thing
water spots-Just a problem where you live? hard water, Salt air ,Dust,dark color?
Rust-I have a spot where the CB antenna sits,you could sand and re-paint with a touch up paint
HTH
Wayne

might also want to try flushing the radiator. if you don't know whether it's been done or not it can't hurt. might also want to clean the nss and fill it with dialectic grease if you really want to get thorough. may not be necessary but you will need to do it eventually.

hth

as far as the water spots.......i had them on a car caused by well water....too much iron i think...........you can clean the windows with comet or another mild abrasive cleaner.......there is probably a chemical(wax type products)that will remove the spots from the paint, but i haven`t had any luck with them.......i used a high speed buffer with a very fine polishing compund to clean the paint....which will work great on the windows too.......make sure the compund doesn`t have wax before using on the windows.........

I have a heard with the coil on plug arrangement it is recommended to repalce those "boots" when you do a tune up. The boot between the coil rail and the spark plug. Like any spark plug wire the insulation properties of the "rubber" breaks down over time.

If you have to be into your dealer and are on good terms with a mechanic or the parts counter guy then ask about replacing the boots. I'd think they would sell them in sets of six.

Roof Rust & finish

I too have roof rust on my '97 XJ. But only on the "peaks" near the curling metal area above the windshield. Sound right? I paid abotu $70 for a guy to clean it up and repaint it, still looks rough. On the H2O spots, ditto the regional water thing, and try a different car wash, then use a shady spot to go at it with soem NuFinish, little at a time, careful to keep off the black trim plastic or chrome. Stuff is amazing. I have a 91 F-150 I got for nothign because the paint was so faded. $8 worth of NuFinish and a sore shoulder it looks like a $2,000 truck - worth fixing.