Everyone's giving you good advice.
Is there a check engine lamp?
You should be getting a Code 11 if the CPS sensor is completely
dead. If there's no check engine lamp/code then the sensor is flaky. It works sometimes, and not others. That drives a diagnostic test at a shop nuts, and leads you to spending lots of money for nothing.
The issue of no spark, no start with starting fluid, and no voltage to the coil. This points directly the TopDeadCenter (aka: CrankshaftPositionSensor) sensor. This sensor must send pulses to the computer. The computer then sees the pulses and turns on the ignition and fuel injection system. If there's no voltage on the positive side of the coil while you're cranking the engine in START mode... then you know it's about a 99.99% chance that that CPS sensor is bad.
As has been said, check it's wiring. It's not dressed too well and can migrate over to the exhaust components and melt the insulation. Then lots of bad things can happen and drive you nuts trying to find the problem.
If corrosion is built up on the pins in the connector between the CPS and the Jeep's wiring harness, then simply unplugging and plugging the connector can break down the corrosion and restore the connection. It's worth a try. If this works, fill the connectors with Dielectric Grease. It will help to keep the corrosion at bay.
Another problem is that the wiring will break internally, inside the connectors, and you'll never see it. So, if you start poking around you may restore the connection and the Jeep will start. You'll be happy, jump in the Jeep and drive away... only for it to happen again. Also, this problem will drive you nuts because there's nothing to physically see.
The CPS is located up on the top of the bellhousing.
The manual says to test:
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Disengage the speed sensor connector from the ignition control module, then install an ohmmeter between terminals A and B as marked on the connector. The ohmmeter should read 125-275 ohms on a hot engine for 1991 vehicles and no resistance for 1992-95 vehicles. Replace the sensor if the readings are not as stated.
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The test usually doesn't tell you a thing...
It's really tough to get to... lots of socket extensions and U-joints and some controtions on your part and you'll get it out.
In short... Change that puppy!