Agree with DrewBuddy with old wiring and thorough inspection but just odd that the jeep quit after a coolant flush . Suspicious , but more likely coincidental. Rather than tell us the past history of what was done to get the jeep running again , let's cut to the chase . Along the way , try to think of anything that may be part of the equation in regards to prior work performed. Ok , we know there is no spark . We'll get to fuel later as we'll need to check TBI injector wiring plug for signal from ecm . That is for later if need be , but for now , let's deal with ignition.
Some things to check ; pick up coil in distributor ( providing its an HEI unit) oil pressure sending unit switch harness . The small gauge wiring gets brittle inside distributor from pick up coil to ignition control module and will cause no signal therefore no spark. The oil pressure sending unit is a safety item as well as a gauge sender . It will cut out the fuel pump if the engine does not start and when engine stalls . This is to prevent fuel from continuously reaching engine compartment in the event of a collision. The oil pressure switch wiring is important but I'm leaning more toward the pick up coil and its wiring first. If the pick up coil dosen't put out a spark to the ICM , the ignition coil will never make spark. Either that distributor's got a pick up,coil,or a Hall effect switch but if that part or its wiring to ICM failed , that's a no spark/ no start.
Start with inspection as DrewBuddy posted since most faults and fixes are found right there and helps to speed up repair . Heck , you might even find a worn vacuum line while your at it. All these little things help. But yes , inspection . Must find why there is no spark before proceeding. The oil pressure switch wiring will cut fuel but not spark. We'll deal with that later if need be.
