I have the same problem with my 93 and I've narrowed it down to the ignition
module in the distributor....although I haven't changed it yet. It is stuck
in the driveway.

You say you have spark because once it starts it runs....but you need to
stick a test plug or timing light on it and watch it when you crank and it
won't run. I'll bet you don't have spark (and ignition pulses) regularly.
That is what mine is doing. If it can get a few sparks in a row, the
injectors will open and it will run and stay running.  I would have bet a
paycheck I had spark until I put that inductive light on it....now I'm
singin' a different tune.

Put a pressure guage on your fuel line by the intake manifold.  I had
the same problem.  Mine would start after a while but kept getting
worse.  My fuel pump went.  Make sure that you are getting between 60
and 66 psi.  I replaced alot  of sensors before I broke down and
replaced the pump.