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I think my Jeep may be possessed

I have a 1999 Jeep Cherokee that has been doing strange things for the last couple of months. First, sometimes I will crank the car and the idle won’t hold so I will have to drive it with two feet until the transmission switches into 2nd gear and then everything works fine. However, if I don’t drive it to make it work, sometimes I can just turn it off and then back on and it works fine too. But Like I said this is a random occurrence, like once or twice a week, with different times of day, temperatures, weather conditions, and irregardless of whether I have been driving it for hours or just cranking it for the first time of the day. The other weird thing that has been happening is that about three times over the last 4 weeks I have been driving and the battery gauge shoots all the way up to 19. The car still works fine but because I don’t know what the problem I usually pull over, turn it off, and then restart it and its fine again. Finally, the other day I drove it to work and then home after work, ran inside for 20 mins, came back to crank the car and the battery was drained (dome light was barely on). When we jumped the car off we had to leave the cables on for 15 mins before it would even crank, but it eventually did and again worked fine when I drove it around for the rest of the night. Any ideas on what the problem is? Someone mentioned a voltage regulator to me but I don’t understand how that would effect the car’s idle.

"I have a 1999 Jeep Cherokee that has been doing strange things for the last couple of months.

First, sometimes I will crank the car and the idle won’t hold so I will have to drive it with two feet until the transmission switches into 2nd gear and then everything works fine. However, if I don’t drive it to make it work, sometimes I can just turn it off and then back on and it works fine too.

But Like I said this is a random occurrence, like once or twice a week, with different times of day, temperatures, weather conditions, and irregardless of whether I have been driving it for hours or just cranking it for the first time of the day.

The other weird thing that has been happening is that about three times over the last 4 weeks I have been driving and the battery gauge shoots all the way up to 19. The car still works fine but because I don’t know what the problem I usually pull over, turn it off, and then restart it and its fine again.

Finally, the other day I drove it to work and then home after work, ran inside for 20 mins, came back to crank the car and the battery was drained (dome light was barely on). When we jumped the car off we had to leave the cables on for 15 mins before it would even crank, but it eventually did and again worked fine when I drove it around for the rest of the night.

Any ideas on what the problem is? Someone mentioned a voltage regulator to me but I don’t understand how that would effect the car’s idle."

No disrespect intended, but I had to do that to understand the post.

The voltage regulator is part of the alternator assembly. Have your charging system and your battery tested. Have them check all your cable connections also.

By the way, how old IS the battery?

Sorry about the formatting…was typing really fast.

Anyways, the battery is less than 2 years old, but can’t remember exactly when it was purchased.

Have them check the battery, charging system, and connections. Post back with how you make out.

Actually, the voltage regulator in this vehicle is likely part of the engine computer. You may have a bad ground or other connection somewhere that is confusing the regulator. Also, a bad ground or other electrical connection (or a bad regulator) can cause electrical ‘noise’ that will confuse a vehicle’s computer. The computer and sensors need a solid, reliable reference voltage for the data to make sense, not one that’s fluctuating up and down or with a lot of ‘staticky’ interference in it. Otherwise, it’s kind of like trying to read a ruler when someone keeps moving it on you or moving the thing you’re trying to measure. So this could also cause the weird idle and other problems as well. But the weird idle could be an entirely different problem, like a bad ‘idle air control’.