Toyota 77020-04071 Fuel Pump

If you think your fuel isn't being delivered, first of all, make sure the battery is working and check the entire length of the fuel line for leaks. When you turn on the ignition there should be a buzzing sound produced by the working pump. If it is silent, explore the fuel pump circuitry and its connector. Connect the gauge into the fuel rail and feed line, start an engine, and compare pressure with the value stated If no, change the pressure regulator since it's not giving proper direction for flow. Other test that can be made include checking if there is a vacuum at the regulator in case where pressure is high. It means that your regulator might have some defects if the high-pressure condition does not change. Lastly, ensure that the returning pipeline has been cleared, replace the regulator when necessary, and verify any leaks after you reattach the supply pipe.