1989 Chevy Celebrity 1989 Chevy Celebrity Won't Start in Ho

Engine Performance problem
1989 Chevy Celebrity 4 cyl Two Wheel Drive Automatic 230k miles

It seems when the ambient temperature is above 82ish degrees F, the fuel pump doesn't work -- no whirring, no engine start (cranks, but won't run). In cooler weather, you can hear the fuel pump whir and the car starts right up. What is the issue, but more importantly, what is the fix (other than only using can in less than 80 deg weather)? Thanks for any help or insight.