Honda: 93 Honda Civic engine shut-down, honda civic engine, pro mechanic

Question
Our 93 Honda Civic 5 speed's engine just shuts down after around 30 miles on the highway.  It will start back up in 10 or 15 minutes, but shuts down again in just a mile or 2.  Around town, it runs great.  
When accelerating and shifting, the tach just bounces all around going into 3rd and 4th gears, but smooth on others.  We have had it worked on 3 times. Honda dealership in our rural area is over 30 miles away. All diagnostic equipment here just goes back to 96. A trusted pro mechanic has told us it could be one of a hundred things, most very small and inexpensive.  But doesn't want to tear into it and keep trying, as this would lead to major money, and could still not find problem.  
Any ideas that might keep us from having to try to make the trip to the Honda dealership so far away for the diagnostic?  Or do we need to venture on that trip?  Any help would be greatly appreciated.

Answer
Is the engine light on?Did you get the code yet?It sound like you have a problem with you distributor specifically the ignitor.Also something as simple as a need of a tuneup can cause serious problems.I would have the mechanic change the plugs with ngk plugs check the plug wires and replace the cap and rotor,see what happens,and check the code.And 30 miles is not that far if your machanic cant figure it out.