XJ Tune Up

[Jinx]

Hey guys,
It looks like I need to do a tune up on our 1996 XJ.

I am thinking plugs, wires, cap, and rotor,

But wondering about does it make sense to replace the O2 sensor?

Anything else I should replace/do?

thanks,

 

[Silly Willy]

Wouldn't hurt to check tranny fluid, diffs, transfer case. As far as the O2 I just wait for the check engine light, unless you are seeing any lag in performance.

Also if you are in the market for any upgrades, cold air, 99+ intake manifold, bore out the lip on the throttle body to name a few.

Those are a few I am in the process of. Hope it helps

 

[Jinx]

Good call on the fluids.

I am just trying to get some better mileage out of this thing. It runs great and is really convenient but crappy mileage.

 

[krany]

ive got a k&n cold air intake mount, just needs a cone filter. that should help with power and fuel milage.

 

[muddyjeep]

A high flow muffler helps allot too! Go with a higher flow airfilter setup. And opening up the bottom part of the throttle body helps a ton!

 

[TRNDRVR]

I am just trying to get some better mileage out of this thing.

Over the last few months I have been prepping my 88 XJ for a 3500 mile move through Canada and into Alaska. I too am trying to eek out every MPG I can possibly get. I know I can only go so far, but I have the time to do it, so what the hell!!! :-\

Some of the things I have done is plugs, cap, rotor, and wires. With the Renix fuel injection I have also put in the Ford 19# Bosch style fuel injectors with the 4 pintle spray nozzle. K&N air filter in the stock air box, removed the intake silencer/venturi and I drilled three 1" holes into the fender side of the air box for a little more air.

Some other things I have done is I figured out my cruise control didn't work because the switch on the turn signal control was bad. Ordered one off of eBay for $19.00 shipped. I put a Dynomax cat back exhaust system on. It's usually a toss up between Jegs and Summit Racing as to who to order from. Mine was $108.00 from Summit Racing shipped to my door, with a $75.00 manufacturer rebate, the total cost was $33.00. I believe a system for your year rig is about $30.00 more, but you can still get the rebate. I have also removed the front drive shaft, had Tom Woods triple check it and I tucked it away inside my rig. Drained and filled my trans fluid twice now and will do it one more time before I leave. Drained, cleaned, and filled my diffs with Mobil 1 synthetic gear oil. Going to drain and fill transfer case with Mobil 1 ATF, and going to change my motor oil with Mobil 1 just before I leave.

One last stupid psychological thing I did was I installed a vacuum gauge. Keep your intake vacuum pressure between 12 and 21 pounds of pressure and that is supposed to get your best MPG. Who knows? After all this I should get at least 60 to 70 MPG, but your mileage may differ.

Aside from the basic tune up stuff, which I actually did when I first bought my rig, most of these mods were free to cheap. I shopped and bought everything on sale. I'm probably into this less then $200.00.

This is my story and I'm sticking to it. I hope some of this info helps you out.

Good luck!!!

PS 1988 Cherokee Laredo
210xxx on the clock
About 66000 on the rebuilt motor
3:55 gears, Lockrights front and rear, 29" tires

 

[jeep-N-montero]

I put a Dynomax cat back exhaust system on. It's usually a toss up between Jegs and Summit Racing as to who to order from. Mine was $108.00 from Summit Racing shipped to my door, with a $75.00 manufacturer rebate, the total cost was $33.00. I believe a system for your year rig is about $30.00 more, but you can still get the rebate

Is that Dynomax a true 2.5in diameter? I was just looking at Jegs and I may get one as a spare.

 

[Silly Willy]

One last stupid psychological thing I did was I installed a vacuum gauge. Keep your intake vacuum pressure between 12 and 21 pounds of pressure and that is supposed to get your best MPG. Who knows? After all this I should get at least 60 to 70 MPG, but your mileage may differ.

I never got anywhere close to that... Whats the MPG really at, or am I doing something wrong?

 

[TRNDRVR]

Is that Dynomax a true 2.5in diameter? I was just looking at Jegs and I may get one as a spare.

I cut the factory Dynomax oval end off, but it does appear to be 2.5" in diameter.

I never got anywhere close to that... Whats the MPG really at, or am I doing something wrong?

Taking in mind I haven't changed the t-case fluid or engine oil yet to synthetics, with a roof rack on top I did a test drive to Tremonton and back and I was right at 19mpg. I'm going to see if what I want to take to Alaska can all fit in the back and gain some mpg by not having the rack up on top. I'm hoping for 20/21ish mpg but I'll have to wait and see.

 

[Jinx]

This is my story and I'm sticking to it. I hope some of this info helps you out.

Good luck!!!

PS 1988 Cherokee Laredo
210xxx on the clock
About 66000 on the rebuilt motor
3:55 gears, Lockrights front and rear, 29" tires

Good info thanks,

I would love anything close to 19-20...

My cummins loaded gets better mileage...