Hyundai Repair: no spark, crank sensor, computer powers

Question
i need help diagnosing a problem with my 2001 tiburon. it started as an intermittent problem of cranking quite a bit before the car started(but never failed to start).  a tune up was done, and the car seemed fine for a couple weeks. it failed to start and was jump started by AAA, and a new battery was installed. it was fine for a few more weeks, and then again failed to start, just cranked. later the car started, and i drove it to a mechanic. he found no problems at first, and then the car started acting up for him...he diagnosed a new computer. i believed he told me he was only getting a spark from #4?  the used computer was installed...and now no spark at all!!???    any ideas as to what is wrong?

Answer
If you're not getting any spark, you should check whehter the check engine lamp illuminates for at least a few seconds when you turn the key on.  If so, that's a good indicator that the computer powers up and is looking for the things it needs to see to run the vehicle.  If the computer powers up, I'd primary suspect the crank sensor.  That's the primary item the computer needs to see to fire the plugs.