1995 mustang GT... wont start/will start..ughh!
This was happening to my '94 GT back in Dec2013. After a lot of frustrations of not knowing how long you might be stuck somewhere before it decided to actual start and go....I checked grounds, battery, alternator, etc. and finally my check engine light came on so I was able to pull the codes. The major issues was my coolant temp sensor was bad. So the car was thinking it was overheating and shut itself down for protection. The sensor was $16 and haven't had any issues since.
On my 89 gt it had a bad dizzy. It would not turn on when cold until prob the 20th crank. You should look into it., just to make sure. Once my car was warm i had no prob.