1999 Wont stay running with out giving it gas.

This problem just started yesterday. When I turn the key its slow to crank, once I get it started I have to keep my foot on the gas to keep it from shutting off. If I keep it running for a few minuets it will be fine until I turn it off again. I read a few posts with similar problems and I think its my battery or alternator. Looking for opinions from more experienced members. I took a reading of 13.75V at the battery terminals don't know if that's good or bad.
Thanks

mine did this and i finally think i fixed it after replacing battery cables. I had no clue they were bad because they looked fine but after i cut into the first 4 inches you can see all the corrosion in the wiring.

13.75 is good. But you are saying it cranks slow. What does it check when it's not running? Should be 12.5.

I had the same problem on my 99.
It was the Idle Control Module that was causing the problem. I replace the ICM and have not had a problem since.

XJadam said:

I had the same problem on my 99.
It was the Idle Control Module that was causing the problem. I replace the ICM and have not had a problem since.

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I agree that ICM is likely problem, but also on starting on low voltage, XJ's run rough until computer relearns how to idle. Just wanted to eliminate the easy stuff first.

Khary23 said:

.... When I turn the key its slow to crank, once I get it started I have to keep my foot on the gas to keep it from shutting off. If I keep it running for a few minuets it will be fine until I turn it off again. ....

Click to expand...

Begin with basic trouble shooting of the start and charge systems. Remove, clean, and firmly reconnect all the wires and cables to the battery, starter, and alternator. Look for corroded or damaged cables and replace as needed. Do the same for the grounding wires from the battery and engine to the Cherokee's frame/body. Jeeps do not tolerate low voltage or poor grounds and the ECM/ECU will behave oddly until you remedy this.

Have the battery load tested. If this was your Idle Air Controller (IAC), there shouldn't be any slow cranking. The IAC can be cleaned.

Now that its not so humid the problem has gone away. I am going to clean all the contacts today and get new cables in the near future. Thanks for every ones help

Battery/alternator connections and cables and battery/alternator condition. Load testing is the ONLY way to conclusively tell the condition of the battery. Voltage test with a meter doesn't tell the whole story.

The slow cranking definitely pushes you towards "electrical" here as Tim mentioned...

Went to autozone today and had them test the battery and alternator. They said the alternator was fine. When the battery was tested it said battery low recharge and test again. I'm thinking that either the battery is shot or the wires are.

So what did you find out? Did it end up being the battery? I had the alternator take a dump on me yesterday on my '99. Went to start it and the battery was completely dead. Thought it was odd cause the battery is fairly new.

After jumping, it still would not start. Finally would run if I gave it gas and still had the jumper cables installed. It would die immediately after disconnecting the cables. Replaced the alternator, $130 later, it's running great again. What a PITA though.

For 1997-2001 (and maybe 1996) OBD-II when you (1) let the battery rundown by leaving the lights or radio on, (2) disconnect the battery for an extended period of time, (3) or when the battery goes bad and needs replacing, the engine computer (ECU or PCM) re-boots and the idle settings are deleted. Your symptoms are; difficulty starting the engine without depressing the gas pedal, and the engine will have low idle and may stall unless you keep your foot on the gas pedal. The ECU will relearn the idle settings after a short period of time and the engine will start and idle normally. If the symptoms reoccur, you need to have your battery load tested. Even with low voltage, the engine will start but the ECU can re-boot multiple times and a new battery may be required.

Loose, corroded, or damaged battery cables or ground wires may also cause or contribute to the problem.

I got a new battery on Monday and so far it has started up every time. I'm going to give it a week or so before I declare the problem solved though.

I haven't had a problem since I put in the new battery. So I'm saying case closed.