So I got this '96 Jeep Cherokee XJ that cranks but doesn't start. It's got around 180k on her but I keep everything in good shape. Batt seemed strong.

I used to drive it everyday but this past year I've driven it only about twice a week. It's been just slightly slower to start in the last couple of months, but just barely slower. Was guessing it had something to do with aging plugs or something.

Drove it yesterday and everything was normal like always, sat overnight and today it cranked but didn't catch.

Any ideas on where to start?

 

So far I've been able to run a couple tests..

Hooked up a fuel pressure gauge and first key turn got it up to only 20psi. Second turn got it up to 45. And third and subsequent turns got it up to 48. It only fell to 43 after 2 minutes so I think that means the fuel pressure is good.

Hooked up a spark tester between a plug and wire and it didn't light at all when cranked so I'm guessing I've got a spark problem. I'll start by doing a tune up with new rotor, cap, wires and plugs then see what happens.

 

I'd check to see if it has Spark.
You can check the spark at the spark plugs too,

Then I'd make sure it is getting Gas.
If the gas is old.
I'd drain it out and put some good gas in it and keep something like Starbrite fuel saver in it to treat the ethanol.
I'd also check to see if it has a inline fuel filter and change it out.
When these gets old they can clog up with debris and water.
Water in the fuel is not your friend.

Good luck