Champion COPPER plugs. Be sure to verify plug gap is .035 before installing!

 

That is completely subjective based on driving style and mods. Larger tires and lift will affect your fuel mileage. The amount of crap you have in the back will have an affect on fuel mileage, and improper gearing, which not only affects mileage but also your odometer so the basis of your mileage calculations are wrong to begin with. A stock XJ driver should expect to get between 14 and 17 MPG in town and 18-23 MPG on the highway with a 4.0L Auto 4x4. Slightly better with a 5-speed, better still with 2WD, and much better with a four cylinder.

Replacing your spark plugs (properly gapped), spark plug wires, distributor cap, and rotor are all part of routine maintenance. A well-maintained ignition system will improve the performance and efficiency of your Jeep. Inefficient combustion results in poor mileage. These are all easy things for a n00bie to change with little or no mechanical knowledge.

 

Okay I did some research and I think I figured it out! (what they all are(plugs,wires,cap,rotor))
But if I get all those things how hard would you say it is to install by doing it myself? I would catagorize myself as a novice when doing things like that. (beginner, novice, intermediate, expert)

 

F1Addict:
Replacing your spark plugs (properly gapped), spark plug wires, distributor cap, and rotor are all part of routine maintenance. A well-maintained ignition system will improve the performance and efficiency of your Jeep. Inefficient combustion results in poor mileage. These are all easy things for a n00bie to change with little or no mechanical knowledge.


Ha! thank you! thats what I was looking for! You guys were talking about it in "slang" terms!
Btw what would you say is the best plugs to get for the 4.0?

 

Thanks tjwalker

 

champion coppers

 

Can you buy a "tune up kit" with all the parts included or do you have to buy them seperately?

 

I'd say if you get under 10 you have a problem to address

 

Thought id just report back with whats up with mine. Ive got the manifold off and being replaced right now, and also changing the O2 sensor out. Ive soaked the injectors to try to clean them abit considering I cant find any 703 now. Ive cleaned out my intake manifold and head ports. Changed the valve cover gasket as well. Hope my mileage comes back some after this. Ill go after the cat later if I feel the want to.

 

ha i get 11 mpg but thats because im not regeared with 33's. But when you replaced your cracked manifold, if you dont replace your engine mounts which are def cracked and the reason your manifold cracked, itll just happen again

 

also if you let your cat get too backed up, there goes your engine. not something to mess with too long

 

if youre asking such a basic question like that id suggest finding someone who does know what those parts are and assist them in replacement of said parts so that you will learn. if you put the plug wires in wrong youre screwed or wire the cap wrong, or cross thread a plug

really not slang its just what most people call them that have a basic grasp on what these parts are.

seriously im not trying to be a douche but it wasnt nessessary to inform us of youre novice status it came thru pretty loud and clear, good luck and happy learning

 

And many of your remarks weren't necessary. Practice what you preach.

I'd say do the work on your own. The best way to learn is the hard way. You aren't screwed if you plug in a wire in the wrong spot. It'll run like crap, you'll realize it's running like crap, then you'll realize the mistake you made and you'll fix it with no harm done. But yes, if you cross-thread a spark plug, you would be in trouble. Try not to do that.

 

Just had to replace the head on my bike because of a cross threaded plug :/ dont take that lightly but a little over a year ago i didnt know anything about cars or trucks and now i just replaced the piston in my jeep alone and my friends call me a gear head now cause i answer all their car troubles. Just takes some courage to do some stuff yourself but i think you could learn easy!

 

x2