Also make sure the battery is fully charged. Also clean the battery cables as they may have scale that causes electrical resistance, so sometimes low power can make it through, but when the more power is needed, it fails. Commonly called "clean the battery cables".
The jeep started last year. When i went back to fix the no oil pressure problem it will crank but won't start. Have replaced the ignition coil crank sensor and the oil pressure sensor. Fuel pump kicks on when I turn the key, it has gas. None of my gages are working. All fuses in dude boxes good. Where do I go next. I'm a single mom in need of help lol