Hey Guys I'm gonna jump into the basic stuff this weekend on my new to me 98' xj 4.0, Since its been awhile for me, what brand spark plugs and wire sets do you guys recommend , I wanna go with a "good set for the money" but if I have to drop a few extra bucks to get the real " good stuff " then I will, also what if anything should be purchased for the distributor? I am open to suggestions/ help with tips and such, that relates to this particular tune-up I'm doing... Also I'll be doing an oil change too, so sugg. on oil and filters brands would be cool too....
Thanks,
shaner

 

Oil... Something API-SL spec'd. Filter.. Purolator,Wix, Napa Gold

Plugs and wires... You don't need to go crazy here.. Something name brand with a good reutation...

 

For wires I just went with napa brand since that is where I went and I run champion plugs since the 4.0 likes things simple.

 

As far as plugs run what ever is on the emissions sticker under the hood (RC12LYC) don't buy into the platinum superduper 15 electrode $5 dollar plugs 4.0s don't run very well on these. I recommend a cap and rotor replacment also, I use all Mopar parts for this because they are of very good quality. Check your local dealer thay may have a kit that containes a cap, rotor, wires, and plugs for a good price. Clean the throtle body and IAC motor assembly with a carb cleaner and replace the gasket.
On oil changes I run 1 can of Engin Restore with a PH16 Fram filter and 10w40 oil as my engin is high milage with over 200K miles and I use a name brand oil.

 

Only problem I have with what BLKXJ has to say is the oil filter. I would use just about anything but a Fram. I like Wix and Purolater but usually run a Mobil 1 filter with the Mobil 1 oil. But my engine is not high mileage. Champion truck plugs, the copper ones are what I run. As mentioned in an earlier post Cherokees like the simple stuff. The more fancy you go the less they like it.
Glad you are asking what to use before you go to the expense of something you will regret later.

 

Groovy information guys, It really helps, I pretty much swore of those 5 dollar plugs back in my motorcycle days. I agree totally , "keep it simple"....
Thanks, and I will appreciate more info from whom ever has more...
Thanks ,
shaner

 

Those fancy platinum plugs spark faster, which sounds great in theory, but the only thing that'll do to a Jeep motor is throw off its timing and make it run like crap. Those plugs are only meant for cars like new Corvettes that have computer-controlled timing sensors that adjust the engine's timing to whatever modifications are made. Just a little "FYI".

 

this is interesting. i did a tune up right after i bought my 90(it was in desperate need), got bosch platimum plugs(single electrode) and wires because they were on sale. ive never owned a jeep before, and knew nothing about them then. but for me, they seem to run great(engine runs smooth with plenty of power). of course my only reference is the old plugs, so based on what i read here if i switch to just the basic plugs it'll run even better?

 

Just run your current plugs until they need changing unless they start giving you problems.

 

I agree with Kyle. New plugs are cheap and easy to change, so when you start to hear it run a little rough then change them out. Maybe a couple of weeks or maybe a few months, each Jeep is an individual case.
Blue

 

Great info guys, But my xj seems to idle alittle rough also, I wanna knock those things out just for the sake of me knowing when its been done.I mainly wanna try to increase the gas mileage the best I can, just so I can feel like I bought this thing to drive rather than sit and conserve gas ya know. if I can save a few m.p.g, I'd be tottaly happy with that, and won't feel guilty joy riding on the trail, since I have LOADS of off roads to cover....
Thanks,
shaner

 

Let us know if the change makes any difference in MPG!