I had somewhat the same problem a few years ago...put the car in the garage, did some work and then cranks but wont stat. If i rember well, i was not geting any fuel (or maybe spark?), anyways the car would run with the relay bridged, and after checking all the electrical (including the fusable link by the battery) it turns out to be the connection on the fire wall, on the passenger side where the positive witre runs from the rear of the car to the front, then splits to go to the starter and fuse box. Make sure that is clean and tight. Othere then that check the crank sensors, on the side of the trany, if one of them in gone the engine will rotate but not start...
Hope this helps!
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