AccordCoupe00

Thanks for having me guys. I have 1991 Honda Accord SE. Problems all started when I though I could do timing belt change myself. Had issue with tension, so got help from friend,got it aligned then went to start no spark. bought new coil,didn't work, got ingnitor then I got spark, but ran light crap. Hired mechanic from craigslist, came out, said I had bent valves, got refurb head back on, ran great after that for about 3 weeks. Then when car would get warmed up, the tachometer would start to jump erraticaly while drive, bogging out car and then sometime die. Problem got worse and worse until very weak to no spark. I bought new distributor from ebay. Installed, same thing. Got car to shop, they said bad ignitor, car started burning up their ignitors,and another distributor. Then they said that the battery was overcharging to 18 volts. They stated the alternator was putting out fine,so they put new battery same thing. So thats where we are at, usually once care drives for a little while ignition starts to fail horribly. Please help, my shop is scratching there head. Whats left? Computer? Voltage Regulator? Bad Wiring? I can tell you when I tried to do timing belt I ran the car for 3-4 minutes with no alternator belt hooked up, could I have done some damage? Hope this helps! Thanks guys