I have a 1997 ford f150 4.6 2wd. It appears to not start at temperature over 80 degrees. If I take off the fuel cap and let it sit for a while it will start. The fuel pressure is with in specs. It is about 32 psi on idle it jumps to about 40 when vacuum is disconnected also it holds pressure after it is shut off quite well. There is a tsb about the same problem, it has to do with winter blend fuels but it did not solve my problem. The truck has not DTCs and the fuel filter was just replaced by myself. I think it might have to do with the fuel pressure sensor or maby with the evap.

 

Have you checked the fuel pressure when trying to crank the motor over 80 degrees?

 

yes it is zero, it took a while because it was a bout 60 all week.