1996 Jeep GC Laredo, Drove it home, parked it in the back yard, un-hooked a little trailer, went to start it back up and all it does it crank. No Fire. I pulled a plug and no sparks. Can't figure out what happened. It was running great all the way home. (And the Trailer did not have any electrical hook ups, so that should not be a problem.

may be un hooked lots of people have no idea how to repair things so unhooking turs them off

at tdc your rotor has to be pointed at five o' clock for the engine to start. first position the oil pump slot at 5 and 11 o"clock and when the distributor seats the rotor must point at 5 o clock. it will not be centered on the #1 cylinder position, but a little before.

As with any no start issue, someone will need to check for spark at the plugs and fuel pressure at the injectors to proceed.
Could be a relay or the fuel pump, or a long list of things.

Check to see if the fuel pump is running after it shuts down...could be a relay or the pump itself (overheating internally) Checked the fuel filter yet? Some crank sensors need to be shimmed. If it's too close to the flywheel even though you recently changed it, if it's too close to the wheel it can fail again. May not be the case but worth checking over. Also check the ceramic resistor on the left fender near the master cylinder if you have one. That too can cause problems.

There is a 4wd module which should be located above the glove box area. Listen for a click while shifting into 4wd from that box. If no click, look there first. Also look at the multi-pin connector on the transfer case. They are very small pins which will, if bent, wont sit properly.

Does the vehicle crank for extended period of time upon first starting? If so the fuel pump needs replacing.

the simple fix might be the park interlock cable. this locks the shifter unless you press and hold the brake pedal while selecting gears. I've seen and replaced a few of these on several chrysler/dodge vehicles.

guys i had this problem it was the brake light in the window center bulb was bad drove me nuts changed all the bulbs in the third brake light and it went away

It sounds like you have some **** in the gas tank that is being drawn to the pickup blocking it.
Have seen this and because it seems so random, it can drive ya nuts.

You might carry a coffee can with you and pull the line from the fuel rail when this happens stick it in the can and just have someone turn the key on for a few seconds.
Beware though, it comes out with force.

Also possible is a failed fuel pressure regulator.
Those aren't expensive and . . . well, not very good either.