won't start after filling up with gas

try starting with fuel cap off?

so it took u an hoour to start at gas station ?

sounds like you arent getting spark for one reason or another, not sure if you have a timing belt but if that broke then that will stop your distributor from turning if you have one which I think you do being a 91.

if not getting spark it usually cam or crank sensor , inspect all vacuum hoses also

Filled it up at a gas station (engine running - I know) had no problems. 20 to 30 starts later she wouldn't start. Check for spark and it was OK. Had no pressure when I depressed the rail relief valve. Next day when I came with the tow trailer it started right up. Any Ideas?? Tried check the relay but unsure of connections.

Your fuel pump may be going out, you should be able to hear it prime for 2-5 seconds when you first turn the key on but dont start the car.

Don't know if this will help. I had hard starting problems and it turned out to be the fuel pressure regulator. Stopped at station, started rough, pulled 30 feet to parking. Fuel running out of manafold. That could also explain no pressurfe at rail relief valve.

fuel pump

Be sure to check the purge valve. I have had mine changed 3 times now. If it sticks open the vacuum it is trying to block will pull fuel out of the tank into the manifold when you are filling up. Code will read as a P0455 on the ODBII scanner.