mattmurphync

I have a 1998 Jeep Cherokee XJ Limited with about 195k miles on it. When I start the car, everything is fine, but when I pull out of a parking space in reverse and then attempt to drive forward, it feels like it's in neutral until it "catches" again. Once it catches, it's fine until I have to come to a stop again. Sometimes when I try to move forward after stopping at a light or stop sign, it does it again. Other than the stop and go, it's fine. It shifts perfectly and I have totally normal acceleration.

Another thing I've noticed, is that it runs rich. I get a cloud of black smoke from the exhaust when punching the accelerator hard, but that could be a completely separate issue. It's eating gas like a son of a gun, too!

Does the start/stop issue sound like my transmission is going bad? I need to take it to a shop, but I want to explore the possibilities before taking it in for repair. I'm also thinking about replacing a few parts myself, if at all possible, to narrow it down.

Thanks for all of the help!!

CodeXJ

Never fear, my friend, I think we can help you!


Let's start with the black smoke first. Black smoke is usually a sign of carbon buildup, possibly from running too rich. Couple that with your 'eating gas' statement (although if your expecting 20+ mpg, your sadly mistaken), I'd say it's time for a full tuneup. Here's what you'll need to replace:

• Spark Plugs
• Distributor Cap
• Distributor Rotor
• Spark Plug Wires
• Air Filter

You'll also want to check the hose running from the valve cover to the filter housing, this tends to split at the filter housing and should be replaced. You should also pull the small hard plastic line off the back of the valve cover that runs to the intake manifold, and clean it out, they tend to fill up with gunk.

After you do that, I would really recommend buying a can of Seafoam and reading the directions. After you do the seafoam, the next tank of fuel you buy, pour a bottle of Lucas Fuel Injector cleaner in it. It's not as 'industrial strenght' as the Seafoam, but it works great.



Now, on to the transmission! What you are describing can be several things, but the cheapest and most common solution is to have the transmission fluid flushed and refilled, with the filter being replaced at the same time. If this doesn't do it, then the problem is more severe and may require a transmission shop to properly diagnose. I usually recommend doing the flush/filter change first though, since 90% of the time the fluid is original to the transmission and pretty much shot which can lead to slipping like you are experiencing.

Good luck!

RV3FLYER

SOrry for breaking in but i could not figure out how to post a question. Have 97 grand cherokee laredo 4.0 4 wd. The problem crank it up put it in gear nothing happens i can go thru all the gear selections and nothing happens.
shut the jeep down atart it back up and it shifts into gear. sometimes i have to start and stop it a couple of times before it works. Whats going on?

b4wheeler

I have a 1996 that is doing the same thing......

I am going to change the fluid, but that is most likely not it.....

What is most likely the problem is the three shift solenoids in the trans...

While you are in there cleaning the trans filter screen.. you might want to change the solenoids at the same time....

On the same note... when it does this, try shifting down to first then back to OD and see if this cures the problem.. I can shift to 1st at stops and back to OD and the trans up shifts fine.. It is strictly a down shift problem....

CodeXJ

Does it work fine once it starts working?

What's the fluid level?

mattmurphync

Wow, so much info and so fast! Y'all are awesome. I'm going to try changing the fluid and see what happens. I'll also get the tune up done, but I'm going to take it to my mechanic for that. Thanks again!

CodeXJ

I'd have the mechanic change the fluid/filter on the transmission and due the tuneup myself. Tuneup will be like $40 in parts, if you can pick up a wrench you can due a tuneup.

Hope you get things straightened out

mattmurphync

OK. I had the transmission fluid flushed, changed, etc. today by my mechanic. I had Advanced Auto hook up the diagnostic thing and it said I had an Upstream O2 sensor failure. I bought the O2 sensor, as well as spark plugs and wires. I'm going to try and tackle this right now! I hope I don't ruin my precious Jeep!

I know I should probably start looking into getting a new vehicle (probably a newer Grand daddy), but this 98 XJ has been so good to me.

BTW, my very first car in 1997 was a 1985 4WD XJ, which I managed to flip and total within six months. I wish they still made these Jeeps because I'd finance a new one. I've always just paid cash for used cars. Not having a car payment is awesome.

mattmurphync

I can't get the O2 sensor out to put in the new one. Did the penetrating oil, used the socket, tried hammering a little. Next is the blow torch move, but that is something I'll probably never use again. I don't have a garage or anything, so I'll just take it to someone I guess.

mattmurphync

I replaced the upstream o2 sensor and within a week my mileage was back to around 16mpg... No more black smoke either! She's still slipping out of gear when I come to a stop sometimes, but at least that's not getting worse...