Runs fine when cold. But impossible to start after warming up. Engine turns but no joy. Wait until it cools and starts right up. (Although it does seem to struggle just a bit more tthan it should when cold). Things I have done:
-Checked MAF: OK
- Cleaned throttle body - new gaskets
- New plugs
- New distributor and cap
-checked coil - resistance OK
Checked fuel regulator - has vacuum / clean
- Checked (and double-checked) vaccuum lines installed new hoses. No leaks.

Other things I am looking at are replacing wires (the ones installed are relatively new), replacing EGR valve, replacing engine temp sensor, replacing air temp sensor (under air filter), replacing coil (even though it checked out ok), replacing O2 sensor, remove/replace catalytic converter

I am getting desparate...trying to not spend any more $'s than necessary. Any idea or suggestions are so welcome and appreciated. Hope someone has had this happen and will provide the magic bullet.

Has there ever been any fuel system modifications or mods to the routing of fuel lines? Vapor lock occurs when a fuel line is very close to a heat source and effectively boils away the fuel in the lines, which could lead to this. Follow your fuel lines and see if they get really close to the exhaust anywhere along the line. if it's something that simple, fixing it could be free.