Originally Posted by thavillain
Is there a way I can test the battery without buying a new one?
Buy yourself a cheap Digital Multimeter....you do not need an expensive totally accurate one.
With the meter set to DC volts put it across the terminals of the battery...with Jeep of it should read about 12.5 volts.
As you start the Jeep the voltage must not drop below about 10 volts and then while the engine is at idle the voltage should shoe about 13.5 volts.
This generally shows a good battery but make sure the battery connections are clean and tight, the negative battery lead where it attaches to the chassis is clean and tight and the earthing strap grounding the engine to the chassis id clean and tight both ends.
As stated, swap the Fuel Relay over with an identical one next to it, make sure fuel filter is clean. Also swap out the ASD relay with another one.
You need to get some codes read out to see what it is complaining about...a bad crank sensor or a bad cam sensor often causes this problem...a code reading should point this out.