Jeep stalls at idle

My 99 Jeep Cherokee has redeveloped a problem that went away on its own the last time. When I try to start it up, it cranks but won’t turn over unless I depress the gas pedal slightly. Then it will run until I take my foot off the gas, when it stalls out. The last time this happened to me, the problem went away after about 3-4 days before I got around to replacing the battery I thought was the problem. I’ve left the battery plugged into a charger overnight with no success. Is my (rather old) battery truly dead, or am I in worse trouble?

Is this a stall at idle? Or a stall when starting? Different issues. The cold start is a special time for modern engines. They use a cold start setting for the injectors to rich the mix. It could be a bad temp sensor.

It stalls when starting (or rather won’t start without a little gas, but stalls if you let back off the gas). I’ve not tried taking it on the road or running the engine in park more than 15 seconds or so as restarting at every stop doesn’t sound very appealing to me.

It sounds like your Idle Air Control valve may be sticking when cold. When the engine is warmed up does the idle speed stay fairly constant under varying conditions, i.e. when shifting, when the A/C comes ‘on’, when power steering is loading, etc.? If you haven’t had the throttle body and IAC cleaned recently, I would give that a try?

BTW is this a V6 4WD Cherokee with power steering, automatic, and factory A/C?

Hope this helps.

It is the 4L 4WD version yes.

As for your other questions, since the problem has cropped up, I haven’t tried driving it. I tried idling it for about 2 minutes in my driveway (holding the gas down to keep it running) but that long didn’t clear the problem, it stalled right back out when I let off the gas.

I second the IAC valve as the most probable culprit.