I've been having some weird problems with my xj. For a few weeks its been getting hard to cold start in the morning. Started as just and extra second of cranking and is now a good 30 seconds of cranking and backfiring before starting. I figured this was just time for a tune up but the other day when I was about town I got back in it in the parking lot, hit the ignition and nothing. No starter, no whirl, no chug, no click, no crank. Tried it a few times and then while the key was turned I bumped the gas pedal and it started up no problem but the idle was really low. On the gauge the needle was below the last tick before zero. It wasn't a rough idle, just low. Sometime during this my radio lost power because it was reset when I got it started. I ran it for a bit and the idle normalized so I drove it home. I tested it a few times and it didn't crank once out of the 20 or so times I tried it and all the other times it still had the low idle. The next day I tried it in the morning and it took a lot of cranking to start but once it started the idle was fine. I'm not sure if everything is related. It'd be nice if I could resolve this without taking it to the shop. I'm kinda leaning towards maybe a computer or sensor issue. If you guys have any bit of insight on this I'd really appreciate it.
2000 Jeep Cherokee
4.0 l6
Automatic
[EDIT] There is no check engine light btw

First,check all your grounds.

I had a similar problem, it was my starter. I made a video on it if you're interested.

I think I got the second problem figured out. I think the first is a tune up issue and the second was a wiring issue. I was working on some wiring and left a relay loose while I was working on it. I think the relay was making contact somewhere and causing that problem. I fixed the relay because it needed to be done anyway and I have not had the no start/ idle issue. If it comes up again then I'll know otherwise.