AVENSIS would not start unless primed with petrol at the air filter then it starts for the day, next day same problem.

[Simon Viljoen 0]

I Have a Avensis 2004 Petrol 1AZ engine, It will not start in the morning but if you prime it with petrol in the air filter it will start and run smoothly for the day.

But if it stays for long or overnight you have to prime it again to start it. I changed plugs, throttle body, d4 pump, put a new Bosch fuel pump but still does the same.

Again if you reset all the sensors with a scanner it also starts but if it stays for long you have to either reset with scanner of prime with petrol.

[flash22 766]

The system is draining back overnight, does the car start if you cycle the key (not starting it) and let the pump prime

there is a one way valve on the bottom of the fuel rail (aka fuel relief valve) this returns fuel back to the tank

20320-28011 - Valve

90430-12026 - Gasket (sealing washer)

 

Also there is the fuel pressure damper 23270-31050 that may cause issues