99 Cherokee 6 cyl. It ran fine until my wife left the door open all night and it was about 20 deg outside. I get in and try to start it and of course the battery is dead. I hook up a battery charger/starter to it and put it on the 70 Amp start setting. It cranks but doesn't start.
I first check for spark. Spark is good. The plugs have plenty of fuel on them and I can hear the pump come on. Compression is good. All of the fuses are OK. So why won't it start. I went ahead and put new plugs and wires on just for kicks. I have heard about the crank position sensor going bad but I thought it wouldn't spark at all if it was bad.
Any ideas or suggestions are appreciated. Thanks

have you let the battery charge fully? 70 amps is not enough to proporly crank it. if you have fuel and spark the thing will run. let the bat. charge.

After my initial attempt I put the battery on slow charge and fully charged it before trying to start it again. I'm very confused at this point.

all an engine needs to run is fuel ignition and compression. you say you have spark. there is your ignition. it turns over fine, there is your compression. and you have gas at the fuel rail and air going into the motor so you have fuel. it should run. have you tried starting it either 1/4 throttle or WOT.

I bought some starting fluid last night and sprayed some in the throttle body. Fired right up. Thanks