What sensors etc. besides the mass air flow sensor have to be working in order for the fuel pump to run? I get no fuel from the fuel pump even though the engine is cranking. There must be other relays, fuses, or sensors I can check even though all fuses I can see are ok. Thanks for your help! Also, how can I check the EFI relay to tell if it is ok? Mel
The circuit opening relay provides 12V power to the fuel pump. This relay is located in the relay box near the driver's side fender. Hence you can verify fuel pump operation by removing the relay and shorting the switched relay terminals at the socket. In general, to test a relay, you would remove it from its socket, use a digital multimeter to determine which terminals are for the coil and which are switched, apply 12VDC to the coil terminals and use the multimeter to measure resistance across the switched terminals. If the measured resistance is greater than 0.5 ohms (after accounting for the resistance of the multimeter test leads) then replace the relay. I suggest that you obtain the electrical wiring diagram for your model year at techinfo.toyota.com so that you can see what is in the path between the 12V bus and the fuel pump. Good luck.
