Hyundai Repair: 1994 Hyundai Problem, hyundai excel, intermittent problem

Question
Hello:

I have a 1994 Hyundai Excel.  The car runs fine but on occassion when warm it will not start.  It does not happen all the time and after it sits ten or fifteen minutes it will start start and run perfect.  Ironically, we took a ten hour trip (didn't shut it off at all for fear it wouldn't start) shut it off (after trip) and it immediately started perfect.  On other occassions, even on a short fifteen minute drive, it may not start. Its been plugged into a diagnosis machine a couple of times.  Nothing showed to be wrong on one occassion and I was told to bring it in at a time it didn't start. This worked as once at the gas station, it wouldn't start and the mechanic was right across the street.  We pushed it there and it was immediately checked and I was told a module was bad.  However, they also said there are six modules and they didn't know which one it could be.  Does this sound correct and or are there better machines that could determine the particular module that is bad?  The modules are about a hundred dollars a piece I was told and I don't want to spend that much if I don't have to.  

Any help is appreciated.

Answer
Hello Justin,
It looks like you have a serious intermittent problem. They are hard to find and requires experience as well as advanced tools. There is only one power module not six. But , can you trust their diagnostic? I highly reccommend you to take your vehicle to a dealer since they have all the tools they need.