4WD trouble...*hangs head*

I drive a '00 4.0 Sport w/ (obviously) 4WD, 81k miles. Only mods to it are a chopped airbox for it to breathe better and 235-75-R15 tires.

Edit: Dang it, forgot to mention its automatic.

THis weekend a problem finally reared its ugly head. I was leaving a rec area so I stopped to put 'er back in 2WD. The light went off but I didn't hear it drop out of 4WD until I'd heard one of those loud clunks that makes you cringe. My check engine light came on right away and the aroma of burnt tranny fluid was there too. An odd symptom...I went to leave and discovered taht if I went over 3000RPM the engine would sputter and shudder, just flat out refused to go any higher. Real rough idle. Just in case it was somethign serious I limped home before turning it off, but once I did and restarted it, it ran fine. My check engine light's still on though, and my tranny fluid's brown.

I HAVE noticed before that in 4low ( I never use that setting in all this sand out here) it becomes a b!tch to return to 2WD...if I had to guess I'd say there's a gear problem but then I know absolutely nothing about transmissions. Well, I know they have gears. Any pointers? I'll have to wait for payday before I can go get the codes read ( no one in town wants to read them for free, I've checked already.)

How do you shift out of 4lo? Transmission in neutral -> lever all the way to 2hi? Shifting out in that fashion works smooth on my 87. what's the purpose of neutral on the 4wd shift lever anyways?

np231

Ya...I go to neutral to shift, tho my buddy ( who has rocks in his skull worse than mine) seems to swear by just sitting in park on the shift column...I'll go totally neutral ( shift and drive column) unless I'm on an incline.

It was explained to me that neutral is on there to make a situation where the gears can travel if they need to. (i.e. shifting from 4H to 4L and back to 2WD. SOmebody correct me if I balled that up.

Edit: Let me emphasize that my buddy doesn't get to drive my junk; I'll let him break his own stuff.

don't let your buddy drive your xj, unless you like the lovely sounds of grinding metal.

i always thought that's what the neutral was for also, but if i remember correctly the last time i tried shifting from 4lo to 2hi, all i got was a rev. just like being in neutral. even though my transmission was in drive

The purpose of Neutral on the t-case shifter is if you're planning on towing the Jeep beind another vehicle, say an RV or other large vehicle when you're not pulling it on a trailer. It disengages the drivetrain from everything else. On 4x4 systems with out a neutral setting in the t-case you have to uncouple the driveshafts in order to tow the vehicle behind anything freely.

99XJSPORT06, thanks for the fill-in! That's a handy piece of knowledge and I'll be passing it along to be sure. But could someone tell me whether my guesses are right, or if they'd check something else?

235-75-R15 on all 4 wheels I hope.
Shifting out of 4wd should always be before you get on pavement . After your back in the parking lot is to late.

Look here for info on how to pull the codes yourself...

http://go.jeep-xj.info/HowtoECUcodes.htm

sorry about thte delay inresponse...but that doesn't work on my '00...it's jsut the gauge/idiot lights test...

If you have a 4.0 Auto I'm guessing you have a 242 transfer case (with full time and part time 4WD) These are 'shift on the fly' , which means you shift settings with the Jeep moving. No need to select neutral, drive steady and straight, and shift quickly from 4WD to 2WD while coasting. Giving the gas pedal a light on/off tap helps the shift to happen. If you attempt to shift while driving a curve or accelerating you may find yourself stuck in 'part time' (center diff lock) 4WD, in which case the re will be considerable driveline 'wind up' making it impossible to complete the shift. To release this, pull onto a loose surface (like your neighbour's nice gravel yard) and with 2wd selected, give the Jeep a couple of blasts at full throttle so the wheels spin, this will release the wind-up and the transfer case will then slip into 2WD.

So does anybody know what was causing the really low max RPM until I restarted the Jeep, or what might be causing the check engine light to come on after I've been in 4WD?

btw, thanks for the tips Aardvark, I'm just trying to make sure my jeep's ready for the trail before next weekend. If that engine light's for something serious then I need to get to the botom of it, but my budget is nearly nill till the 1st.

OK, been a long few weeks...but I finally got back home and a buddy suggested I just try turning the key on and off a few times w/ the tripmeter reset button pushed in. It didn't matter how many times, but it would flash 2.5, which I assume means a code of 25. So...my question NOW is, do the codes stay constant throughout the years, or did they change when the XJ got it's new body style, parts, etc?

I haven't put 'er in 4wd of course, merely around town driving, but that engine light makes me nervous...an we've had lots of storms recently, so the trails are jsut that much better.

Have you tried taking it to Autozone? They will *usually* hook an OBD-II scanner up to it and read the code(s) for free for you.

lost1 said:

I drive a '00 4.0 Sport.........................................................................................................................................................................................( no one in town wants to read them for free, I've checked already.)

Click to expand...

See above dude, I appreciate the advice, but... I guess I got caught in a bad town for it. OK I've dug some more and it looks like a toss-up between an IAC error or AIS motor circuits, which is apparently related to the IAC (Idle Air Controller?)

I still don't know what the hell it is or even where to look under the hood. Is it on the throttle body?

Hey, me again.

OK, got the codes pulled and they were P0205, 305, 300, 304, 175.

Just hazarding a guess, but I'd say offhand there's a problem w/ my fuel injectors...I'm going to check the wiring too, anything else worth checking?

OBDII Scan Codes:


http://www.stu-offroad.com/index.shtml

Thanks otto, but I'm not looking for scan codes. I know it's got to do w/ the fuel injectors, what I'm asking is what to check. I'm going to swap around my injectors, check my wiring...what I want to know is if there's anything else worth looking at.

Hey Lost1 Ensure that all four tires under your rig are the same make AND the same size. Also make sure that they are all at the same air pressure. If the tires aren't the same size or pressure then the 242 becomes a real pig to switch from 4lo to 4hi. Don't figure that just because you have a BFG 235 75-15 on one side and a Goodyear 235 75-15 on the other they are the same size.

I am speaking form experience

I have four matching 235/75R15 tires mounted on stock rims. The issue w/ shifting hasn't reared its head again, HOWEVER...I have a problem w/ my fuel injectors taht I'd like a little advice on. Maybe I wasn't clear enough about it.

I'm sorry if I'm coming off like an asshole but seriously...read the damn thread. I've gotten some great tips on shifting and the like, some of which I already knew. Reminders never hurt, but I'm asking direct questions that are getting ignored (with a few exceptions). There, flame on guys.