im tryin to get better performance out of my 01 xj. any ideas?

 

How many miles does your Jeep have ?

Are you lifted with over-sized tires? If so How much lift an What size tires do you run ?

With the abundance of info you provided us with about your Jeep, I will suggest you use Seafoam in the intake manifold, gas tank, and crankcase, Change the oil, spark plugs, Transmission fluid, and Differential fluid.

 

If it is lifted with bigger tires, regearing your axles will work wonders. After that I would start with a good Cold air intake, better ignition setup(wires, coil, plugs), bored throttle body or throttle body spacer, 2.5'' exhaust with a good free flowing cat and muffler, header, and finally a chip. If thats not enough, I hep you have big pockets lol thats when I would look into a stroker crank/rods, forged pistons, camshaft, aluminium head, roller rockers, nitrous/turbo/supercharger, etc... or just say F**K it, and do a V8 swap

 

FIFY

please don't waste your money on a throttle body spacer, bored throttle body, or upgraded ignition. all of those items don't improve performance enough (if anything) to justify their cost.


see this thread (regarding the TB stuff): http://naxja.org/forum/showthread.php?t=1086166

 

Um I only agree with the spacer.
But I haven't read the link he posted yet to say one way or the other.

 

my jeep is not lifted. i have a throttle body spacer which was on the jeep when i bought it i also got a cone filter instead of the box for more air flow. as for the mileage im sitting around 146k. i would like to do lil by lil so v8 swap is out of the ? right now

 

You can do cold air intake, exhaust, injectors, bored TB, a chip and some stickers and pretend that you're going faster
But it's a 4.0 inside of a brick. It's not designed to go fast or get good gas. You'd have to rebuild it and stroke it
Check out 'Performance Myths' in my signature. Those are some common upgrades that don't really do as much as advertised.
Just clean the hell out of it and see if you can resurrect some fallen ponies

 

No one said injectors...

 

I6 respond well to free flowing exhaust and increase air flow, and injectors wouldnt hurt