Throttle Body Removal and Cleaning

As our XJs, ZJs, or anything with a 4.0 age they tend to have a build up of deposits in different places in the engine.  Filters get clogged up and need replacing, lifters can have gunk build up, and the throttle body and IAC can have a build up inside causing rough idles and a loss of power. And since we love our Jeeps we want to keep that from happening…. right?  This really is a simple task.  It took me maybe an hour taking my time.  I believe this would be a great first DIY maintenance item along with changing your oil.  Plus who want to pay somebody else a hundred bucks to do this?  Total cost was like $5.  And think what you could put that extra $95 to!  Maybe some fresh rims or meat on each corner, new tint, smooth shocks like Bilstein 5100’s, a new sound system, or even some great tools! The options are limitless.  Here’s the simple fix.

Let us know what you would do with the extra dough.


Becoming Immortal


Every once in a while, you hear the term “immortal” applied to a vehicle. This doesn’t mean parts don’t wear out (wouldn’t that be amazing!), but rather that the vehicle itself is timeless. It stands above its contemporaries in such a way that people immediately know there is something special about it. Sometimes it is due to a vehicles performance, its rarity, and many times even Hollywood.  Many vehicles are memorable for good and bad – a ’77 black and gold Trans Am, a ’69 Orange Dodge Charger,  the Yugo – but few vehicles achieve the hallowed status of truly becoming “immortal”. The Shelby Cobra 427, the Ford GT40, the 25th Anniversary Lamborghini Countach – which late 80’s/early 90’s boy DIDN’T have that poster in their room? Heck, even the De Lorean makes the list thanks to Michael J. Fox.  These would all be considered “immortal”. There’s just that particular qualifier in each of them that allows them to ascend beyond just “the memorable”. Add to this short list the ’84-’01 Jeep Cherokee.

Robert Casey, the transportation curator at the Henry Ford Museum, says that the Jeep Cherokee XJ was the first true sport utility vehicle in the modern understanding of the term. It was an instant trend setter. It has often been said that imitation is the highest form of flattery. Well, many companies have made their own imitations of the Jeep Cherokee, with none truly figuring out the perfect blend that Jeep and AMC found. Nissan, Honda, Ford, Chevrolet – they and others have all tried, and honestly failed, to match just what the Cherokee had to offer. The XJ may not be the roomiest, or the most luxurious, or even the most refined small SUV, but just like every other “immortal”,  somehow it’s shortcomings become the things that charm its owners as “personality traits” – or as we know it, the “Jeep Thing”.

One of those traits, but hardly a shortcoming, is it’s off-road capability. In fact it is here that the Cherokee truly stands far above it’s rivals. In 2001, the final year of production for the XJ in Toledo, OH, Car & Driver pitted the XJ against ten other “cute-utes”. Sadly, the XJ finished in 10th, a mere 3 points ahead of the last place Kia. The reason can basically be summed up in one statement: it wasn’t as sophisticated as it’s competitors. However, it aced the off-road segment, so much so that this is what they had to say about it. “The Jeep never got stuck – it acted as though it never would – so we quit our slippery-slope trial before the backing-out distance topped a half-mile.” This is what sets the Cherokee apart. Combine this with all those things that are just part of the “Jeep Thing”, and you have something very few vehicles can claim to be. When a timeless shape, quirks only an owner can love, and stand out performance can all be found in one vehicle, you end up with something quite rare indeed. You end up with something… immortal.

Dana 30 Complete Hub Assembly Swap

All XJ’s use a complete hub assembly. This means that the hub and bearing are one unit as opposed to separate units where just the bearing can be pulled, and then a new one pressed in. In 1999, Jeep changed the hub assemblies due to changing from composite rotors to cast rotors, so be sure to get the proper ones.

Alright, so you need to swap out your hub assemblies but aren’t sure how. Well, here’s how it’s done….

1. Make sure you have the proper tools. Air tools are easy, but with basic hand tools you can get this done on about 30-45 minutes.
What you need:
– Jack and jack stands
– Socket for your lug nuts (18mm, 19mm, 3/4″, or a 13/16″ socket sizes are all possibilities)
– 1/2″ drive breaker bar (or a 1/2″ drive ratchet and a piece of pipe).
– 3/8″ drive ratchet
– 36mm socket
– 12mm socket
– 12 point 13mm socket
– Needle nose pliers
– Pry bar
– Hammer
– Axle grease
– 200ft/lb torque wrench
– Block of wood

Now that you got all your stuff ready, head on out and start working on your Jeep.

We’re just gonna go over one side, as they’re both the same. That, and this is just the tear-down. The reason is because to put it all back together, just go in reverse.

2. Chock a rear wheel with the block of wood and loosen the lug nuts on the front wheels.
3. Jack up the front of the vehicle and place jack stands under the front axle.
4. Finish taking off the lug nuts and remove the front wheels. This is what you’ll have to look at.


5. Start by taking out the axle nut cotter pin and crown cover with the needle nose pliers.


If the cotter pin isn’t too rusted you can bend it back straight and reuse it, otherwise you’ll need to get new ones -one per side.

6. Now that the axle nut is exposed, move to brake caliper. Remove the top and bottom caliper bolts with the 12mm. These are the ones that have the rubber compression boot on them.


7. Remove the caliper and set it on the lower control arm. If you’re not comfortable putting it there, grab a zip tie or metal coat hanger and hang it from the coil spring.

8. Now, it’s back to that axle nut.


Yup, this is the big one. 36mm. This thing is on there tight, so a little PB blaster may help you out, even with your breaker bar/pipe. This is also where the pry bar comes in. Place the pry bar between a couple of the studs so that it acts as a stopper when you turn the wheel while loosening the axle nut. Here’s a quick look at what the set up should look like…


9. Now that you finally got that thing off, pull the washer out as well and we can move forward. Pull the brake rotor off and get that 12-point 13mm out and remove the 3 bolts that hold the hub assembly on. All three are right around the axle u-joint.


10.Alright, now you get to remove that hub assembly.

If it’s stuck a little (or a lot), take that hammer and give a few good taps along the edge to pop it free of the knuckle. Be careful though, if the axle comes with it you’ll need to re-seat the axle. If this does happen, slowly push the axle back into the axle tube. Be careful to keep it centered. If you don’t, you could tear the inner seal and then you’re in for another repair if you wanna keep gear oil in your front diff for any extended period of time.

Once the hub is out, here’s what you should be looking at…


That metal ring is the dust shield for your brakes. Hang onto that, You’ll want to keep it. Congratulations on removing your hub assemblies.

11. Now you just got to put the new ones in. Like I said earlier, just do the steps in reverse. But, before you start to put it all back together there’s a couple things you might want to do/know…
1) Roll a little axle grease into the new hub. They come pre-greased, but trust me, this helps keep junk from getting in there.
2) Be careful when putting the hubs bolts back in. They can cross thread real easily, so thread them in slowly.
3) Torque specs:

Axle nut – 175ft/lbs.

Hub bolts – 75 ft/lbs.

Caliper bolts – 30ft/lbs.
Wheel lugs to 100ft/lbs. After driving 50 miles, re-torque these.

XJ 4.0L Fuel Injector Swap

One of the easiest modifications on our beloved 4.0’s is a fuel injector swap. For some, this may sound like a technical and daunting task, but rest assured, it’s actually quite simple. The reason for this swap is simple. Jeep used 1-hole pintles on their injectors while Chrysler used 4-hole pintles on the rest of their products. The 4-hole pintle allows for a more even fuel spray pattern, resulting in better atomization, making the engine work less and run a little smoother.  The results you gain from this are a smoother idle and better throttle response. Some have seen a very mild gas-mileage gain, but this is due to running clean injectors as compared to the stock ones that are dirty.

87-98 XJ’s use what is commonly referred to as EV1 injectors. This is due to the electrical connection they have. The injector you need is Bosch part # 0280155703. These injectors can easily be found in most 95-97 Dodge/Plymouth Neon, Dodge Stratus, Plymouth Breeze, and Chrysler Cirrus vehicles with the 2.0 engine. Just be sure to check the side of the injector for the correct part number as Chrysler used many different injectors in the mid-90’s and early -00’s. One possiblity for the 87-98 XJ’s though is to use EV1-to-EV6 adapters. These will allow the use of EV6 njectors, making the hunt for the much harder to find 703’s a thing of the past.

99-01 XJ’s received an updated injector, called EV6 injectors. The injector you need is Bosch part # 0280155784. These can be found in most 98-01 Dodge Caravans, Plymouth Voyager, Dodge/Plymouth Neon, Dodge Stratus, Plymouth Breeze vehicles with the 2.4 engine. Again, be sure to check the side of the injector for the correct part number as Chrysler used many different injectors in the mid-90’s and early -00’s.

This image shows the difference between an Ev1 injector (on the right) and an EV6 injector (left)

ev6 ev1

When you’re looking for the correct injectors, just look on the side for the part #. Here is a 784 as an example:


Some people have used 0280155710 injectors from Ford 302 V-8’s, but these have a lower flow rating and do not utilize retaining clips, so some slight modification is needed. With this in mind, I have found 703/784 injectors to work best with the Jeep 4.0. This swap can also be done to any ZJ or WJ that has the 4.0L.

Once you have 6 injectors, clean them up (a simple Google search will give more detail) and make sure to have new o-rings and micron filters. So, let’s get into the step-by-step.

Tools/supplies you’ll need:

– A medium sized flat blade screwdriver
– Masking tape / Painters tape
– 6 new/rebuilt fuel injectors with new o-rings on each end
– petroleum jelly (Vaseline)
– a 10mm deep socket w/ ratchet and extension
– fuel line quick disconnect tool (for 1996 and up engines IIRC)
– a few rags
– 1 hour of time (+/-)

The Process:

1. Unscrew the gas cap.

2. Disconnect the negative (black) terminal from the battery and place a rag on the battery to keep the terminal from touching the post.


3. Remove the air intake tube from the throttle body and stuff a rag in the throttle body to keep crud out. Also disconnect the breather tube from the intake box.

4. Disconnect the throttle and cruise control (if equipped) cables from the throttle body.

5. Unscrew the test port cap on the fuel rail. You’ll want a rag below it as some fuel will spill out.

fuel rail pressure

6. Connected to each injector is a electrical wire. Use the masking tape to label these #1-6 from front to back. You do not want to mix these up when you reconnect them.

7. Disconnect the Fuel Pressure Regulator vacuum line from the intake manifold.

vacuum line

8. Disconnect the fuel lines from the fuel rail. This one is optional, but I recommend it as the lines aren’t very flexible. Up through ’95, just push in the white tabs and carefully pull. ’96+, you’ll need a disconnect tool (cheap at your local parts store).

fuel lines

9. Disconnect the electrical plugs from the injectors. For 87-98 XJ’s, just wiggle and pull. For 99-01’s.use the screwdriver to pop the red lock tab up and then pull the connector off the injector.

This is pretty much what you should be seeing at this point:


10. Remove the 2 bolts holding the fuel rail on. Gently pull the fuel rail away from the engine.

11. Once the fuel rail is off, remove the small metal clips from the injectors. They are right where the injectors meet with the rail. You need to reuse these so don’t lose/bend/break them. The flat head screw driver works very well to pop them off.

12. Hold the rail vertically over something to catch some fuel (a medium tupperware container works very well, especially the kind Hillshire Farms lunch meat comes in) and remove the bottom injector. Some fuel should come out of the opening. then remove the injector from the opposite end. More fuel will come out. Now remove the other 4 injectors.


13. Make sure that all the o-rings from the stock injectors are out of the rail and the engine. If there’s any gunk buildup in the engine holes, use the screw driver to clean the holes. Scrape the gunk off in an “inside to outside edge” pattern, being very careful to not let any crud get into the engine as this would be very bad. Clean the screwdriver off after each scrape.


14. Make sure the new injectors have the new  o-rings and pintle caps on them. Lube all the o-rings with a small amount of vaseline. This will keep them from tearing.


15. Plug each injector into the rail, and refasten the metal clips to “lock” them in place.

16. Firmly press the rail and injectors into place on the engine and re-install the 2 fuel rail bolts.

17. Put a small amount of di-electric grease in each electrical plug and reconnect them to the injectors, following the # sequence you taped to the wires.

18. Reconnect everything – fuel lines, vacuum line, air intake, throttle/cruise cables, and battery terminal.

19. Check the ground. Anything there? No? Good. Recheck everything you disconnected. Is all connected again? Yes? Good.

20. Turn you ignition to “RUN”. DO NOT START THE ENGINE! Check around the injectors/fuel lines for any leaks. If there are none, go to the next step. If there is one, recheck the o-rings on the injectors. if there’s a tear in one it’ll leak.

21. Turn the ignition off, then back to “RUN” for a couple seconds. Now start it up. It may take a couple seconds. If the idle is choppy, wait a few minutes and it should smooth out. If it doesn’t and it’s not running smooth, follow next steps to reset your PCM into a “learning mode”.

Resetting the PCM:

This very simple procedure will Erase the “Adaptive Memory” stored inside the PCM and allow a new “Adaptive Memory” to be developed.

After performing this procedure the PCM will re-learn and store into Adaptive Memory your engines performance characteristics.

Please perform these steps exactly as they are written, in the order they are written. This will cause the adaptive memory in the PCM to be erased and cause the PCM to go into Fast Learn Mode adaptive mode.

Disconnect the battery terminals and touch them together for 30 seconds. (This is to discharge the PCM capacitors, which maintain the Adaptive Memory.)
Reconnect the Battery Cables
Turn Ignition Switch to the “On” position but DO NOT start the engine
Turn Headlight “On”
Turn Headlights “Off”
Turn Ignition Key “Off”

The PCM Adaptive memory has now been flashed, or erased from the PCM.

When you start the engine it will be running off a set of pre-programmed tables that come with the PCM from the factory.

When you get the engine up to operating temperature the PCM will start to collect data for the “Adaptive Memory”.

The PCM will collect data for Adaptive Memory for the first 50 Warm-up Cycles. You will run a little rich until the PCM adjusts for the new air/fuel mix.

**Full credit goes to Justin Raducha for the images used in the write up section of this post**

Cowl Snorkel…

So I have been thinking about snorkels lately.  A little assurance when crossing water or even just when dealing with some of the flooding we get in our area from Nor’ easterns or tropic storms will be a good peace of mind.  So I have a couple options:

Safari Snorkel.


This is the tried and true snorkel. It’s very well made and has great fitment.  It places your intake at the top of your vehicle which will help protect from a lot of water splash.  I can get caught on tree limbs when you are on the trail and possibly break the intake scoop.  It also is extremely expensive! For a 97+ XJ it’s $563.99!!!!  I can buy a lot of stuff for that money!

Chinese ARB knock off.


This looks an awful lot like a real ARB safari snorkel, but it’s a Chinese knock off.  It does not come with instructions or quality hardware.  I’ve also heard their template doesn’t always line up, but as long as you do lots of measuring and test placements it should not be an issue.  I have also heard you need to use a high quality paint to keep it from fading.  If you have a 97+ XJ it also does NOT include a new windshield washer reservoir since you will need to relocate it to run a snorkel. You can  however pick one up from a junk yard for an early to mid ’90s XJ as they are located in the engine back and not inside the fender.  They are only $120 shipped to your door so that makes it intriguing.

DIY snorkel.


Practical, cheap, but usually horribly ugly.  If you want to take this route take your time and do it right.

Cowl Snorkel.


Spectre makes an intake that pulls from the cowl under the windshield.  It effectively moves the intake into the cowl moving it much higher up than stock and still protects from rain as the cowl has its own drain holes to quickly drain out any water.  This option also frees up space in your engine bay for something like a second battery.  At around $180 its not a bad option and looks clean on the outside as well.  Some people do say there is a bit of sucking noise on start up, but that it’s not much of a nuisance.

DIY Cowl Snorkel.


This route is inexpensive and just as effective.  You can pick between the driver’s side or passenger’s side of the cowl.  You can keep the stock airbox or shove the filter up in the cowl and free up some space so it’s more like Specter’s, or you can use the stock airbox. If you have the RTV sealant and the 3″ saw bit you can do this for about $20!  If you keep the stock air box it allows you to keep the price of replacement filters down.

I’m going to be taking the DIY route myself.  It’s just as effective as Spectre’s and saves a bunch of cash.  You can buy flex hose from Advance Auto or whatever your local parts shop is for about $20.  I’ll have to pick up some RTV and something to cut my holes with.  I should be able to do the whole thing with the RTV for less than $50 and still have left over tools.

These threads are my inspiration:

And I personally know this guy.

So hopefully in the next week or so I’ll have some photos or a video of the install up for you to check out.

Brake Pads and Rotors

When I first started working on my XJ I knew very little about what to do.  It was one thing to read it in a book or on a forum, but any visuals I could get would be a HUGE help to me feeling like I could tackle something myself.  Here’s a short video on how to change your brake pads and rotors on an XJ.  It’s only still photos and not an actual video, but I think it’s simple enough even a total newb could handle it.