Fuel pump on 1991 Toyota Camry

Ok, how can I tell when the fuel pump is getting ready to go out?

Asked by for the 1991 Toyota Camry
The Toyota Camry has a pretty good quality pump fitted to it from the factory. If the car is not frequently run out of gas and the fuel fiter is changed periodically the fuel pump is generally very reliable.
Fuel pump pressure and delivery volume can be measured and compared to specification. The amperage draw of the pump can be measured (amperage draw tends to go up as the pump is failing) and finally the fuel pump can be observed using an oscilloscope to look closely at its electrical pattern.