TKC

Kiddos left a light on and I didn't notice for over 12 hours. Weather turned really cold at the same time. After driving just fine for the past few months, went out to start it and it was totally dead. Nothing.

Jumped it and found that if I pumped the gas pedal, it would start but to keep it running, I'd have to keep my foot on the gas. As soon as I let up off the pedal, the XJ dies. Buddy of mine can hear the fuel pump running when I have my foot on the gas and the engine is running.

Thoughts? Suggestions?

Thanks in advance.

salad

That's because the battery went flat. The alternator is only there to maintain a charge, when the battery gets THAT low the alt puts a TON of resistance on the engine. I left my interior lights on in the winter last year (oops) and I had to run it at 2500 RPM for about 10 minutes until it would idle properly. Otherwise I'd let off the gas and the thing would just drag to a halt. But that was still with enough charge to start it below freezing, never mind flat. If the Jeep keeps doing this you'll want to look at a new battery as that kind of abuse results in permanent physical damage in older batteries (sulfation).

belvedere

Yep, put a charger on the battery. Your alternator will thank you.