Hey Everyone,

I'm having an issue with my 99 Cherokee Sport 4.0 and it all started like this:

Jeep was running perfectly, no weird idles, sounds, smells etc..Parked vehicle after driving one night and went to start it the next morning and it wouldn't turn over..charged the battery for about 5 hours or so. I removed the charger and my battery was showing a charge. I tried starting it and I have to pump the gas to get it started and if I lay off the gas while it is running it dies right out.

When manually running the throttle it will die out if i take my fingers of the throttle too quickly. If I rev it quite a bit and take hand off throttle slowly it will stay running and idle normally. I have not had a chance to actually drive it this way to see what it does. What could this be? I have no visible leaks except a tiny spot of coolant located in the center of the jeep about three inches behind the radiator on the ground. When I get it running and rev it up the exhaust smells pretty potent..like I just got done riding a dirt bike....it also smells a little hot but the temp is fine...

all other liquid levels are fine, I've recently put all new front end parts in it a new radiator and a radiator flush..Any ideas?? Thanks for your expertise!

 

sounds a little like the cps i would change it and see, couldn't hurt

 

X2

 

da ta da da, a how to!
http://go.jeep-xj.info/HowtoCPSchange.htm

 

Thanks for the suggestion and link. Much appreciated. I'm going to check it out and see what I find...

 

I'd make sure the battery has and is holding a full charge first.. since as you said it wouldn't 'crank over' was the first sign of a problem. Low battery can cause the idling problems you describe. The battery might start the engine, but it could still be low and your alt probably won't be able to keep it up.

 

Thanks for your response..I am showing a full charge, that's why I'm baffled..weather is no good today, so I'll be investigating further tomorrow.

 

Wow this precisely exact thing happened to me last week with my 99 cherokee sport as well. After gently revving the engine for about fifteen minutes, then it stayed on all by itself. It drove and drives perfectly fine and has not gave me trouble since.

 

My battery died recently. I drove it to work fine, nothing strange at all was happening, then when I got in it to go to lunch, it gave me one crank, then started clicking. I let off, tried to crank again, nothing. Nothing at all.

Hooked a jump pack up to it, and it would crank, fire, then stall. I had to feather the throttle to get it to run, but it would stall as soon as I let off.

I asked one of the tech's why this was, and he said "The computer probably needs to re-learn the idle, so run it longer or try driving it with the jump pack on."

So i did, and it worked. Idled on it's own, just fine.

BUT, died not long after i took the jump pack off.

Have your battery tested before you spend money on a CPS. It's quick, easy, and not ALL dead battery symptoms are the same.

 

Had same issue with my 99 right as I Bought it. After jumping and revving until it idled and drove fine. Replaced battery, and problem solved.

 

come to think of it me too! never connected the two things....

 

For some of you when you completely drain a battery on a computer controlled vehicle they wont stay running without a foot in the throttle for quite sometime before the ECU has time to relearn all it's info, this is for the one's who's jeep ran fine after that first start and stall and then having to keep the throttle on to stay running for quite a bit, than run fine.

 

I had my throttle position sensor give me some issues like this. Sometimes would start and die. Would try to run while applying gas. $25 part at napa fixed it.