91 legend causing headaches on start!!help

[Ferngee]

I have a 91 legend that is causing me headaches.. first.. it starts right up when it's cold... but if I let it run for a while.. and cut it off and try to start it back up then it will not start......... until it's cold again. I have been told. ignition module, fuel pump relay, main relay or the distributor.. The car is not producing any check engine lights.. and when it's running ...it sounds as smooth as a baby's bottom..Oh...by the way...I had a head gasket problem and I tried.. Steel seal.. Well..It worked..but I now have to replace my water pump....I was told that it would ruin my water pump and it did..but other then changing my water pump..my acura is running well.. except for this problem with not cutting on when hot....What do you think the problem is ?????