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 Post subject: UPDATED - 2002 Liberty 3.7L and where do I go from here?
PostPosted: Sat Mar 11, 2017 8:11 pm 
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Location: Albany TWP, ME
I've been searching and found several related threads to my issue, all of them dead-end (I'm on a bunch of other forums for other makes I own, I know this isn't a rare problem). Either there's no answers to the next question or the OP didn't update with the resolution so I'm kinda wondering my next move.

Picked up this Liberty for my better half beginning of the week. No rust, looks well cared for, and the price was right. I got it from a used car dealer "as-is" because it was throwing a ton of codes. Since "perfect" KJs of this vintage in my area go for 4-5x what I paid, I figured unless I had to drop a motor and\or trans in it, I would still come out ahead of the game. I still feel that way, I'm not discouraged, just hoping to get some ideas on what the next best step is. Ok, now that the ramble is out of the way...

The codes were:

P0351 (coil circuit A)
P0356 (coil circuit F)
P0305 (misfire #5)
P0306 (misfire #6)
some code for the O2 sensor with low heat, which I ignored because, hey, I'm misfiring all over the place, no kidding the O2 is pissed off.

So, after reading as much as I could find before purchasing, I knew where to start. My "local" FLAPs (40 miles away) had one coil so I bought it, then ordered 2 more, plugs (Autolite), and injectors from RockAuto. They came yesterday. Pulling the plugs, they all looked almost new (NGKs) but since I got new ones, I replaced them anyway. #6 was wet and smelled of gas, #1 sooty so I knew the misfires were real. I swapped the ASD relay for the blower one just to cover that base as well. Went to start it and figures, the battery crapped. I jumped it, took it for a spin, and it stalled 3 times at idle. Ok. Battery junk, nothing more to do until I replace it. Then it snowed. HARD. So I waited before making the trip.

Today I went and got a new battery. Fired it up and it sounded and felt better, but still a little rough and agricultural. I'm not familiar with the 3.7, all my current and past Mopars have been either 318s or 360s so wasn't sure if this was normal or not, but kinda figured it wasn't still quite right. I should mention that it is -14F with a wind chill of -44F so I wasn't really enthusiastic about hanging around outside to contemplate this. I filled the tank (added 1 can of Seafoam and 8oz MMO), drove it around a bit to bring it up to temp. Seemed to run better (anything had to be better than a 3 cyl, right?), a little rough at low speed. After about 10 minutes, accelerating up to speed, about 3000 rpm it took a dump, bogged hard, CEL started flashing, and bucked a few times. Pulled over, checked codes.

Nothing.

Started up, CEL on solid, now showing P0306 (only) again and running a little crappier than before. Tomorrow I'm gonna swap a different coil over to #6 just on the rare chance that I replaced a bad coil with the one bad one out of the batch of new ones, but I don't have a lot of faith that is going to be the case.

So, my question is, what should I do next? Since I don't have the luxury of running around the corner for parts - yet don't want to throw money away either - I'm going to put together another RA order, I'm thinking of pulling off the right valve cover, I'm thinking my next step would be valve springs? Collapsed lifter? I don't hear any funny noises but with the wind, the exhaust rattling (need to get a new hanger...), I'm not sure if I could hear it or not. That bog maybe not a bog but valve floating? Then again, since it didn't really crap out until it got to temp, maybe the right front cat is also not happy? Or maybe it's not happy because of the miss?

On an unrelated note, the air box that attaches to the TB, the PVC hose from the oil fill attaches to the driver's side, what goes on the nipple sticking out of the passenger side? I checked the FSM and couldn't see anywhere a diagram?

EDIT: Apparently there should be a hose from the plenum to the passenger side, guess I need to find out what happened to it.

Thank you in advance for any advice.


Last edited by snoopydance on Mon Mar 27, 2017 3:45 pm, edited 1 time in total.

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 Post subject: Re: 2002 Liberty 3.7L and where do I go from here?
PostPosted: Sun Mar 12, 2017 7:01 am 
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Location: Presque Isle, Maine
Is it still just 6 showing up? Pressure test, then pull cover to visual. That side has a lot of crap over it. A/c lines and such.

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 Post subject: Re: 2002 Liberty 3.7L and where do I go from here?
PostPosted: Sun Mar 12, 2017 9:30 am 
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Location: Albany TWP, ME
Yeh, just six. I was reading last night that if a miss code comes up, the ECM cuts the injector to save the cat until shut off and restarted, which would explain why shutting it off stops the CEL blinking until it freaks out again? If this is true, then the #6 plug dripping of gas has me wondering if maybe it's the injector? If it ever warms up today, I'll try swapping it out. Of course it's the cylinder that is buried, couldn't be #1:(.
The bog and bucking is what has me stumped. I thought if it was just the coil or injector, it would just miss and lose power. It felt like when I had a broken wire on the fuel pump on my RAM, and bog, then picked up, bucked a few times then smoothed out but still missing. I swapped out the ASD relay with the blower relay (blower works fine), so eliminated that. The other thing that has me suspicious is the bog didn't start until it came up to temp, which got me wondering cat or O2. I'm not afraid to wrench and pretty decent with older systems, computerized is still black magic.
Appreciate your response, I'll update as my experience moves forward (or back...) so future members might benefit.


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 Post subject: Re: 2002 Liberty 3.7L and where do I go from here?
PostPosted: Sun Mar 12, 2017 11:56 am 
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Location: Presque Isle, Maine
Yeah its never number one! All my issues are with 4 when they arise:)

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 Post subject: Re: 2002 Liberty 3.7L and where do I go from here?
PostPosted: Mon Mar 13, 2017 11:18 am 
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Ok, thinking out loud, I've noticed most of the thread where people have these similar issues are in high-mile situations (150k+). I did some thinking over the weekend and wonder if at least part of this is a fuel delivery issue. I know that the fuel filter on the 2002s is outside the tank and a "life of service" part but suspect that possibly Jeep didn't think that "life" would be 150k+? Since the fuel filter is also the regulator, I'm going to pick up a pressure gauge and look at that. Here's my thought and feel free to poke holes in it, as I have two different issues that may or may not be related. First is the miss, second is the bog and buck. The bog and buck feels like fuel-related. I tried something yesterday, I took it out for a spin, the bog hits right around 3000 rpm and last almost 2 seconds, and then I get two to three bucks after I let off the gas. I'm wondering if the fuel pressure is low enough that the bog is from starvation, which then kicks in the ASD, then when the revs drop down, it kicks back on, causing the buck?

That got me thinking about the miss as well. When I looked at others' threads on this, a good 80% look unresolved after swapping out parts all over the map and all seem to highlight #6. #6 is the last cylinder on the fuel rail. I wonder if the pressure is insufficient enough that the end of the chain isn't getting sufficient pressure to be consistent? Since you don't have to drop the tank (yay, since I just filled up...) to do both the filter and the pump, regardless of what results I get when I do a pressure test, I might just replace both the filter and the pump since the are original, the cost isn't that bad (~$200 for both through RA), replacing them doesn't look too bad compared to many other vehicles (doing them on my RAMs involves unbolting the bed and jacking them up with an old bumper jack), and I'd rather do them now instead of being stranded in the middle of nowhere Maine when it's -40F out. If nothing else, it is peace of mind since this is the better half's ride and right up there with scorned is "hell hath no fury like a woman broke down on the side of the road because the man didn't be proactive." Ok, so that probably isn't written down any place but we all know it's true...

I've been using Car Doctor as my OBD2 app, just grabbed Torque as well to see if I can pull some better data as far as fuel delivery and other metrics. Fingers crossed...


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 Post subject: Re: 2002 Liberty 3.7L and where do I go from here?
PostPosted: Sun Mar 26, 2017 3:25 pm 
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Following up, it is now fixed. It had several issues, all contributing to the codes and poor performance.

1) three out of six coils were bad
2) #6 injector was cracked
3) #6 injector plug had the tab broken off and zip tied in place
4) several cracked vacuum lines
5) right side breather hose MIA
6) Crudded up fuel filter (probably the worst job to do out of all of them)
7) both rocket arms for #6 laying in the head

I scoped #6, the valve seats are good. The lash adjusters were locked up solid, tried to pump them with no luck, couldn't get them to move until I used a vise. No, wasn't going to reuse them just was curious:). Put in need lash adjusters, replaced PCV that I snapped off (grrrrrrr), spliced in new injector connector, replaced all coils, plug, injectors, filters, and vacuum lines. No codes, nice idle.

Took it for a spin. Ran great until I stepped on it to go up a hill, then right about 3k, it bogged HARD, dropped to about 1200, bucked twice, and the smoothed out. No code but the CEO started blinking. Shut off restarted, no CEO so drive it gently home. Ran fine. Replaced fuel filter - Mother Mopar, why make an access panel and the COAT IT WITH THIRTY TONS OF RHINO LINER??????
#&$@!!!
The worst part of this entire saga was the darn filter. 30 minutes of chipping, scraping, and prying finally popped the hatch. Another 40 minutes ofswearing in my back in melting snow fighting with the ONE STUPID NUT that holds the filter in place (it's 3/8th btw, since you can't see it and I used a 10" extension on 1/4" drive ratchet and it still was a very tight reach). Brown fuel dribbled out the outlet end, not much better in the feed end hooked it up, primed it with a few key cycles, crossed fingers, prayed to Saints Sox & Martin (I believe they are the patron saint for all Mopars, though just in case I tossed a Petty, Inman, and Hall for good measure), and went for a spin.

Runs
lovely


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 Post subject: Re: 2002 Liberty 3.7L and where do I go from here? Get her d
PostPosted: Sun Mar 26, 2017 7:36 pm 
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Snoop, You are indeed a Saint. You stuck with the investigation while philosphying continually. I don't know if I would have perservered as much as you.
You sure got her done though. Thanks for educating us all.
:BINGO:

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 Post subject: Re: 2002 Liberty 3.7L and where do I go from here? Get her d
PostPosted: Mon Mar 27, 2017 2:56 pm 
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Joined: Tue Mar 07, 2017 9:24 am
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Liberty for All wrote:
Snoop, You are indeed a Saint. You stuck with the investigation while philosphying continually. I don't know if I would have perservered as much as you.
You sure got her done though. Thanks for educating us all.
:BINGO:

Thanks :) I have incentive... it's called if momma ain't happy, NO ONE is happy :D. I've gotten so much good advice over the years on the different forums I'm on (here, RamForumz, TheSamba for my other vehicles), that when I have something that works, I like to give back if I can.

Ok, so a few things to possibly help others if they end up tackling this (which let's be honest, it's not uncommon with the 3.7), primarily targeted towards the novice or "I'm so non-mechanical novice is a compliment" person.

First, don't be scared. It's not that bad and you don't need any real magical, technical skills. Hell, you don't even need any fancy tools. Read the forums, use google, get the FSM - Factory Service Manual (skip those Haynes and Chilton ones, they have more errors than accurate info in them) though unless you are mechanically skilled, the FSM isn't as much help as others' real-world experiences, but it's good to have and reading it will help you get "more technical." Maybe. Or not. Ask questions. Listen to the answers. Give details when asking questions, no one gets all dedicated to helping someone who can't bother to offer up more than one or two sentences, knowing they are going have to drag stuff out of you to get some idea of what you are having for an issue. Don't - unless you are really good friends with them and they owe you some big favor (and if they do owe you a huge favor, let them do this for you instead :D :D :D ) - go bugging your local mechanic (technician). They need to make a living. Giving you free advice isn't helping them make a living. Don't ask them to borrow their tools either. Buy your own. Avoid the bargain basement, "101 piece tool set!!" for $9.99. Yes. There is a difference. Many of those cheap, cheap ones only have a passing relationship with the Imperial or Metric system. A "heaping teaspoon" might be a thing in the kitchen, a "loose 10mm" is not a thing in the garage or driveway. You don't need to have a 10,000 drawer Snap-On setup, a simple reasonable set is good to get started. You can get a reasonable decent set of Stanley, New Britain, Husky, or chain auto part store brands (usually made by the same companies that make Stanley, New Britain, SK, etc.) on a budget. You can add more tools as you need to. Look for both SAE (inches) and Metric (MM) in one kit. I'd recommend a kit that gives you 1/4, 3/8, and 1/2 drive sockets up to 17-18mm and 3/4" in both standard and deep sockets, plus a selection of combination wrenches. A couple of flat head and Phillips screwdrivers, selection of pliers (slip joint, linesman, needle nose, and at least one locking "vice grip" style), an adjustable 8" wrench (aka "crescent"), and a screw driver\hex\"torx" bit driver set... this is NOT a replacement for real screwdrivers but in addition to.

Get a code reader. I'd recommend one of the inexpensive ELM-327 bluetooth ones - they sync with just about any android phone or tablet (as well as laptops with bluetooth as long as they aren't Apples), there's free apps like Torque Lite and Car Doctor that will tell you what the codes are you are getting. Sure, you can to to Autozone or Pepboys and they will read them for you, but that's not always an option if it's running like crap plus, knowledge is power.

So, if you are getting P03xx codes, you have a misfire. There's two different segments of the P03xx codes, either P035x or P030x (where "x" is a number between 1-6). Using that code reader I suggested to get will tell you what cylinder(s) are having issues. Starting from the driver's side of the engine while looking at it with your legs up against the bumper and hood up, the front one on on the driver's side is #1. #2 is the passenger front side. They alternate side-to-side to the back of the engine, so that means that driver's side, front to rear is 1, 3, 5 while passenger side is 2, 4, 6. With this info, we can then determine the following codes mean issues on the respective cylinders:

P0301 - cylinder #1
P0351 - Coil circuit "A" is cylinder #1
P0301 - cylinder #2
P0351 - Coil circuit "B" is cylinder #2
P0301 - cylinder #3
P0351 - Coil circuit "C" is cylinder #3
P0301 - cylinder #4
P0351 - Coil circuit "D" is cylinder #4
P0301 - cylinder #5
P0351 - Coil circuit "E" is cylinder #5
P0301 - cylinder #6
P0351 - Coil circuit "F" is cylinder #6

Ok, so to do coils and plugs you'll need:

- 10mm socket and ratchet (3/8th drive is good size for leverage and space) plus I'd recommend at least a 6" extension, 10" to spare your knuckles
- 5/8th spark plug socket
- Flathead screwdriver
- pliers (slip joint aka "channel locks" work best here)
- bungie cord
- plug gapping tool - $1 at FLAPS (Friendly Local Auto Parts) or Walmart
- Packet of thread anti-seize (usually stupid cheap and at the checkout at FLAPS). Grab a packet of dielectric grease too.
- On-plug coils - anywhere from $4 for cheap ones at Rockauto.com to WTF-are-they-thinking $90 each from some dealers. Shoot mid-range is my opinion ($24 ea up here in the middle of nowhere). You can replace just the one that is bad, or you can replace them all. Your call based on finances and how proactive you want to be.
- 6 copper core spark plugs. Don't drink the koolaid, the iridium and platinum ones? Not better. Actually worse. Bonus, copper cores are cheaper too. I like Autolite or Champion, OEMs are NGKs. Years of Asian motorcycles have made me not a fan of NGKs. I've taken on of the standard NGKs apart. The electrode is a finish nail. Kinda makes me question the rest of the line. YMMV.
- spray can of silicon lube, NOT penetrating oil or any petroleum oil (that means no WD40!)
- 1/2" combination wrench
- green scotchbrite (or dollar store knockoff) pad. If you steal this from under the kitchen sink, don't let the better half see you. You're not going to give it back.

Use 1/2" combination wrench to loosen nut on the negative (black) battery cable where it attaches to the battery. Lift up and remove from battery stud. Push it down next to the battery so there's no way your elbow hits it and lets it make contact with the battery posts. Do the same for the positive (red) cable. Yes, those who are experienced know you only NEED to pull one, but bear with me, at the end you will get why I say both.

Loosen hose clamp on the air box to resonator hose (black hose going from big black box with "Jeep" on it sitting on the passenger side fender to the black thingy sitting on the top of the middle of the engine that says "3.7L"). You can leave both black box things on, but I'd recommend removing the air box to give you a little working room. It has 3 nubs on the bottom that fit into rubber sockets in the fender. It will not want to come out. You will make it. Grab the box and rock it north-south, then east-west while pulling up. Eventually it will let go, if you are short like me (5'2"), that means it will let go right into your chin. For this reason, keep your mouth shut while pulling unless you don't like your tongue. Set aside.

With the pliers, squeeze the clamp on the small hose attached to the top of the coolant reservoir that comes across from the driver's side of the engine, that's the plastic tank up against the firewall on the passenger side. Remove the hose, you might have to twist it a few times with the pliers to loosen its grip on the nipple. Move it over to the other side of the engine, try to position it so the end is facing up to minimize dripping antifreeze all over the place. I tuck it up between the hood and the hood support. Using the 10mm deep socket, remove the two nuts that hold the reservoir to the firewall, then pull the tank forward. Do yourself a favor, put the nuts back on the studs a couple of turns so you don't lose them. Tip the tank sideways to the passenger side and use a bungy cord to keep it in place, around the hood support rod works well.

Use the flathead screwdriver to press the little clips down on each coil plug while pulling each plug off. . You can use your fingers if you want, but it's much easier to use the tool :). Using the 10mm socket again with the extension, remove the nut holding the coil down. Pull coil straight up to remove. Put nut back on stud so you don't lose it. Use long extension and plug socket to remove spark plug. Stare at plug end. Marvel the color. Fight urge to keep them "just in case I need one later." Trust me, you don't. You never will. Throw away. Get new plug. Set the gap per recommendations, using your new little tool. It's simple, slide the tool into the gap between the curved part of the end of the plug and the little stubby metal cylinder sticking up out of the center. Check what it says. Bend the curved part until the gap is where it is recommended. Wait. What are those recommendations???

Autolite and ACDelco: 0.035
Champion and NGK: 0.044

LIGHTLY put the anti-seize on JUST the threads. NOT on the other parts. A little goes a long way.

Use the extension and plug socket (without the ratchet attached) to screw the new plug in. First, check to make sure the plug goes in the socket enough to hold it, but not enough that it is going to hold onto to it so well that when you get done and pull the extension off, the socket stays buried in the head and on the plug. This is not fun. If this happens, you have two options: screw it back out, adjust the plug in the socket and try again, or dig the socket out with needle nose pliers. Since I didn't list these pliers in the "things you need," you know what I prefer to do.

Ok, ready? BE GENTLE. If it doesn't feel like it is moving smoothly... STOP. Back off, line up again, and try. You do NOT want to cross-thread this. No, no, no. Tighten with fingers until it is tight, then put the ratchet on and give it one quarter to one half turn. Do not over-tighten. All you want to do is seat the "crush washer" on the plug down. Repeat on the other 5 plugs. Put the plug socket back in your tool kit before it ends up dropping down next to the engine and eventually on the side of the road, after banging off the bottom of your rig and giving you one of those "what the hell just fell off my truck and am I gonna die????". Ask me how I know...

Now for the coils. Remove the nut off the stud, set it up on the cowl at the base of windshield so you don't drop it. Gently but firmly push each coil down over the top of the spark plug, lining up the stud with the hole in the coil until it seats. It won't click or "pop," you can tell you have it all the way seated by looking at the relationship of the coil with the stud, if it is almost all the way down, you did it right. Thread the nuts onto each stud finger tight. Take your 10mm socket and snug each one down until the coil seats against the bottom of the stud, then 1/2 turn more. Do not over-tighten. Push each coil plug onto the coil until it clicks. Put the coolant reservoir back on the firewall. Connect the overflow hose. Hit each one of the rubber sockets for the airbox with the silicon lube. Press box down into the sockets. Attach black air hose.

It would be a shame to do all this work and end up with having a crappy battery connection, sooooooo, take scotchbrite pad, scuff up both battery studs until they are nice and shiny. Slice off about 1/4 of the pad, across the short side. Roll it up to make a tube. Push into the battery clamp, then pull in and out until the inside is shiny. lightly coat each battery post with the dielectric grease. Reconnect positive battery cable first, tighten down. Wiggle with hand to make sure it is on good. Repeat with negative cable. Smile. Cross fingers. Cross toes to be safe.

Start engine. Does it sound better? Smoother? If yes, take it for a spin. Look for the CEL (Check Engine Light). If it stays off after 10-15 minutes, you are probably done. If not or if it doesn't sound right when you start it, time to dig a little deeper. It's ok, you can do this. Trust me. You can. I'll post the next step (in my opinion) - injectors - in the next post.


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 Post subject: Re: UPDATED - 2002 Liberty 3.7L and where do I go from here?
PostPosted: Tue Mar 28, 2017 1:37 pm 
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K, next? Injectors. Same tools needed above for the coils (since you need to pull the coils out to get the fuel rail off) plus a few more things:

- 6 plastic sandwich bags with 6 twist ties
- T25 torx bit and socket
- 8" or longer 1/4" extension
- 1/4" ratchet
- some sort of plastic or soft-ish hook. I use a crochet hook from the dollar store. It costs, well, a dollar.
- injectors (if you are getting a miss on selected cylinders, you can get away with just the number of them you need... or buy all 6 and hopefully don't have to worry about them again for a while)
- injector seal kit, even if replacing injectors with new. The kit is like $8 and if you happen to break a seal or lose one, you have them on hand.
- a couple of small trays or containers. If you have kids that like those Snackable things, they are perfect for stuff like this.
- automotive fire extinquisher

Optional:
- injector connector replacement plug
- solder
- soldering iron ($12 at Walmart with solder if you don't have one)
- wire cutter\strippers
- razor blade
- 14-16g wire shrink wrap (electrical tape doesn't cut it)
- large wet sponge (again, don't let the better half catch you)

Have extinguisher ready. I like to make this my first step anytime I'm dealing with fuel, the whole ounce of prevention thing. 15 seconds of prep and $30 for an extinguisher can save you thousands in insurance deductibles - auto, health, home - as well as considerable pain. I'm a VEMS, I've seen some pretty nasty burns. They suck. Bad. Don't be "that guy (or gal)."

Open up the power control center. That's the black box in front of the battery (as in towards the front of the Jeep, towards the headlight) on the driver's side. Find the Fuel Pump Relay. Remove it. It just pulls up and out, might need a little encouragement. If you have big fingers, you can gentle grip it with your slip joint pliers but DO NOT SQUEEZE HARD. With that out, start the Jeep. Depending on how long since it last started, it may not start at all, otherwise, let it run until it dies (a few seconds), then try starting again. If it doesn't start, you pulled the right relay and are ready to move forward. What you just did is release the pressure in the fuel rails by running it out of gas :)

Do the steps in the previous post up to removing the spark plugs (in other words, pull the coolant reservoir, air box, coils). Don't remove the the plugs, that isn't needed for this process. Instead, remove the throttle body resonator (black thing that has the "3.7L" on it). To do so, first disconnect the two black hoses that connect to either side of it and move them out of the way. With the screwdriver, loosen the hose clamp on the back of the resonator. Put the torx bit on your extension and then on the ratchet. Underneath the resonator on either side are the torx screws. Back them both out until they are loose all the way, they will not come out like a wood screw but stay in the rubber isolators behind them. With a rocking motion and pulling towards you parallel to the engine, remove the resonator. Set aside. On the back part of the throttle body you will see another hose that connects on the left side. Pull it off. It is part of a larger S-shaped hose that wraps over and around the engine to the PCV valve, a fragile, annoying if you break, part that is attached to the oil filler tube on the right front of the engine. You can remove it if you dare or plan on replacing it, otherwise, carefully rotate the S-hose over to the right side so it lays against the right fender. If you hold the nipple of the PCV valve while doing this, there's a good chance it won't break. If it does break, twist it counter-clockwise until the nipple that snapped off would be pointing to 6 o'clock, then pull straight out. Don't replace with new until you are done with the injectors. Yeh, they are that brittle and at $20 ea, worth only doing once.

Got it so far? Feeling overwhelmed?
Don't. Grab some coffee. Take deep breath. If you smoke, this is the time to do it as the next step involves gasoline and yeh, not a good mix. Now do a visual inspection. Look at the plugs that connect to the injectors. Do they all have a red clip on them? If not, are the black plastic tabs that you press down on to remove the connectors not broken? If the answer is NO to this, plan on replacing the connector. If YES, then disconnect the plugs from each injector (CAREFULLY slide the red clips toward the wires going into the connector, they break easy:(, then press down on the black tab and pull the connector off the injector). Look at the injectors themselves. Are they cracked? Do they move side to side easily? Plan on replacing any that are cracked. Any that move easily might just be a bad seal (vacuum leak) and the injector may be still good.

Ok, so still with me? Looking down at the engine, that U-shaped series of tubes the fuel rail. That will need to come off so we can get to the injectors. Since I'm lazy, I'm going to describe the "incomplete" way to do this - we aren't going to completely remove it from your Jeep, just lift it up and rotate it. If you look down on the sides of the big tubes that run north-south, you can see 2 bolts on each tube that attach it to the head. Get your 10mm socket with the extension and remove each one of those bolts. Put bolts in your plastic tray so you don't lose them. Think I have a phobia about lost fasteners? I do. If you ever had to spend hours going through the bins at FastenAll to find that one bolt that is NLA (No Longer Available) from other sources, you'll quickly appreciate this. As a side note, there's something coming up that is kinda like that. Stay tuned. I know, the suspense must be killing you...

Grab both of the sides of the fuel rail. While lifting firmly, rock side to side. The injectors might be a bit "sticky" so take your time. The thin tube that connects the two rails is just crimped on, it doesn't take much to loosen it up, causing a fuel leak of epic proportions once fuel pressure returns. Fortunately, it is easy to fix by just snugging up the crimp tabs again with pliers.

Are the injectors out of their holes on both side? Good. Lift the right side up over to the left, then flip the whole rail upside down, lay it back down. Now you should have all six injectors pointing up like little soldiers. On the ends of each should be O-rings. If any are missing, this is where the crochet hook comes into play. While trying not to swear too much, hook any that were left behind out of the injector sockets. Throw away. If all you are doing is replacing seals, remove any O-rings from the injectors. Do it gently, they should roll off with your fingers, give them a little encouragement with the hook if needed. Roll the new ones on, put a little lube in the injector sockets, and reverse the process you used to take the whole thing apart. If you are replacing injectors, let's keep going.

Take your plastic bags, put one over each injector, then loosely twist tie in place around the metal nipple on the fuel rail. See those little metal clips at the top of the injector? Those hold them in. They also seem to never be in stock online or at FLAPs, yet they are important and easy to lose. Right, not quite NLA but hell, might as well be. If you lose them, it could be 6-8 weeks to get new ones. Yeh. Seriously. Anyway, through the bag you should be able to pop them off the injector and rail with your fingers into the bag. With the bag still on, pull off the injector from the rail. This keeps any stray fuel from dripping all over the place plus prevent (hopefully) you from losing the clip. Flip the bag upright, remove the injector (leave clip in bag). If you got rebuilt injectors, box them up to return for core. If not returning for core, you can test them and see if any are worth keeping. Testing injectors can be found all over the internet, all it takes is a couple of jumper wires (or even better, that spare connector you may have bought) and a battery.

Put your new injectors in the bags, then put the bags back on the rails. Push the injector into the rail through the bag with the part that the electrical connector plugs into facing the inside of the "U," then push the clip back on hold the injector in place. The clips fit around the nipple on the fuel rail and into a thin slot on the injector. Tug lightly once the clip is in place to make sure you got it right. Rinse. Repeat. Ok, don't rinse but... If you have to replace any connectors, this is the time to do it, otherwise, skip this next section.

To replace the connector, with your razor blade, split the factory wrap that is fused around the two wires back about 2" then split the two wires apart. This is a good time to get your soldering iron hot. Snip the old connector off close to the connector. Strip back both wires about 1/2". Slip the shrink wrap over the stripped wires and push back as far as you can. Grab your new connector and twist the wires onto the old wires, keeping red-red, black-black. There's several schools of thought on the "proper" way to join the wires, I prefer the loop-through-loop method, others may recommend a different method. Once the wires are joined, put your wet sponge under the join of the wires. This will make sure any solder splatter lands on the sponge, not on the head (and possibly some gas or oil). Solder the wires together. Let cool for a few seconds, then slip the shrink wrap over the join. Run the soldering iron over the top and bottom of the shrink wrap without touching, close enough to seal the join. Once connector(s) replaced, hide the sponge and move on to next step.

Once all the injectors are on the rail, lightly lube the injector sockets in the head - motor oil works good for this or any petroleum-based lube. The key here is LIGHTLY. You don't want a bunch of oil dripping all over the place, just a light coat, not enough to deep fry some chicken. Flip the fuel rail back upright, line up the injectors into the sockets, and gently but firmly push down on the rail until all 6 are seated. Bolt the rail back down, push each connector on until you hear a click, then slide the red tab to lock them in place, then reassemble all the crap you took off in reverse order. Don't forget to put the fuel pump relay in before you reconnect the battery. Once everything is hooked back up, turn the key on to RUN but don't start. This will pressurize the fuel rail. Turn off key. Check for leaks, especially around the top of the injectors and the rail crimp points. If you have leaks at the crimp points, just lightly squeeze the tabs down, going all around the joint with pliers until the leak stops. Turn key back on and make sure leak is gone. If leaking around top of injectors, make sure you got the clips seated firmly, 99% of the time this is the issue.

All set? Fire it up. Run better? If so, put the extinguisher on the front seat or floor, then take it for a spin. I recommend not venturing too far from home, just a couple of runs around the neighborhood for about 15 minutes is good. Watch for CEL. Pay attention to your nose for fuel smell. If all is good, congrats!!! If not, well, then it's time to go the next step and pop off the valve covers. We'll cover that next.


Last edited by snoopydance on Wed Mar 29, 2017 1:27 pm, edited 1 time in total.

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 Post subject: Re: UPDATED - 2002 Liberty 3.7L and where do I go from here?
PostPosted: Wed Mar 29, 2017 9:03 am 
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Wow amazing post :mrgreen:

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 Post subject: Re: UPDATED - 2002 Liberty 3.7L and where do I go from here?
PostPosted: Thu Mar 30, 2017 6:12 am 
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All great advise I have to add the inexpensive ELM-327 Bluetooth scantools don't always work I bought 3 before I gave up and spent the $ on a good one all 3 worked great on the wifes KK.

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