Mike Husted

I just picked up a 4 door 91 4wd 6cylinder automatic that has 232k. Some problems it has is:

1. When taking off from a stop it feels like it's stuck in 1st. I read somewhere that it could be the speed sensor clogged up. If anyone agrees let me know where it is.

2. Hasn't happened yet but the previous owner said that if the car heats up and is running at temperature that if you turn it off it won't turn back on until it's cooled off? Any shot in the dark here helps.

3. Sometimes right after starting it cuts off or wants to bog out. Tune up?

Thanks for any answers to these.

ZJMAX

Ok on my 94 Grand Cherokee the speed sensor for the transmission shifting was on the transfercase.

The no start when hot could be a weak bendix on the starter. Getting heat soaked after running and not being strong enough to work properly. My old chevelle has this issue and when I was broke I would carry a jug of water to pour down on it to cool it off enough for it to work lol

Max

cruiser54

Have you taken the time to check the level and condition of all your fluids yet?

Radi

Is it shifting late out of 1'st, or not shifting at all? When does it change to 2'nd?

#2 could be the ignition coil or CPS (among other things) if it's cranking but not starting. Those two are known to be heat sensitive. Might be causing #3 as well.

Yes, tune-up if it needs one. Plus see Cruiser's comment.

Mike Husted

I haven't had the time and I barely drive it. So I'll give the car a good once over sometime soon.

Mike Husted

It shifts late. Like if I punch it it goes nowhere until it shifts out of first but I can't remember if it's a high rpm when it does it. And is CPS a coolant pressure sensor?

Nickusaqw

Crankshaft position sensor. Located near the firewall on the transmission housing. Cruiser has some helpful tips for testing it. I suggest doing all of his tips as they will fix most of the issues you have with your jeep. (If there's any others)

Mike Husted

I'm thinking you might be right on that. Weird thing happened the other day. I went to drive it around town. Started up, stalled out, started up then drove it. But my buddy pointed out my speedo stopped working. We stopped at 7/11 to grab some sodas and I cut it off and when I went back out it started right the hell up. But the speedo still wasn't working. Then it randomly came back on. So I'm wondering if the speed sensor is giving it starting problems. I'm gonna order a new one because they're not too expensive.

Nickusaqw

I'm not 100% sure but I believe the 91 automatic used a gear that is spun by the rear part of the transfer case.(assuming it is designed similarly to the 1990 Cherokee) So if you lose your speedometer I would first check down on the back part of the transfer case to make sure the cable/sensor head isn't loose then follow it into the dash. Im fairly confident on mine you can adjust the how the two gears mesh with the retaining clip and bolt but my jeep has a ax15/231j trans and transfer case so yours maybe be different. Just an idea you may want to try.

GregGA

This.

How does the trans fluid.look and smell? The AW4 TRANS pan has a drain bolt. It's easy to drain the pan and get about 1/3 of the fluid out. Fill with about 4 quarts,drive it a couple of miles and do it 2 more times. You will have gotten 90% of the old fluid out. We don't know your mechanical skills , so this method is easy. I use MaxLife Dex/Merc ATF. It's full synthetic and cheap at Walmart.

If your fluid is brown and smells burnt, change it out and let us know how it drives.