1993 Toyota Corolla won't start after the fuel pump being changed . What else could be wrong with it for it not wanting to start ?

Was it running well before? Are you 100% certain the problem was the fuel pump? Are you certain the fuel pump is getting fuel to the engine now if that was the original issue? Were the fuel filters replaced? Is there fuel in the tank?

Yes it was running well thought it could have been the fuel pump so changed that . Yes there is fuel getting to the engine that's why the filter wasn't changed and yes there is a half tank of fuel in there now . Is there a control moduel for the fuel injectors ?

That's part of the ECU, Did you check to see if the timing belt isn't broken? Don't remember if Toyotas are interference engines or not. If you look in the valve cover cap and see if the cams rotate when the engine is being cranked.

So if it was running before, what made you change the fuel pump? I'm not very clear in all of this...

You say it was running, but you changed the fuel pump and now it doesn't run. There had to be a reason why you actually decided to change the pump.