Does BT 20V ECU prime fuel pump?

[Vezza]

Hey guys,
Just wondering if the BT 20V ECU is suppose to prime the fuel pump when ignition is on?

[sundee]

im just writing becasue no one has, this was brought up somewhere mid topic in here, the 4a ecu doesnt prime the fuel pump, i think HEN the NUT will be able to confirm this or golberg, but i think it only switiches the pump on once u engage the starter.

[Grant #2]

I know for sure the BT ECU doesn't prime the fuel pump. The pump turns on with the starter switch, and continues running when the ECU knows the engine has caught and is running. The ECU keeps the pump running.

On a ST, it's the same deal, but the AFM keeps the fuel pump running as air pulls the flapper open. The ECU is not directly connected to the fuel pump in this case.

[Vezza]

Ah sweet, Thanks for that guys. The motor starts and runs fine but I just thought it was a bit weird the fuel pump didn't prime, just a bit of peace of mind to know everything is wired correctly.

[jaz_ae86]

Toyota fuel pumps have non return valve/design. No need to prime.

[Vezza]

Hmmm... I'm using a nissan pintara fuel pump, not sure if it has a non return valve. Do you reckon it'll matter?
Would it basically mean if I didn't use the car for a couple of days it would take a bit longer to crank the engine over?

[Nikkojoe]

Pretty much ^^

Although I think it will take less than a day for it to happen. As long as it starts reasonably quick I wouldn't worry anyway

[Vezza]

I've left it for a week and haven't noticed any difficulties starting, guess it must have a check valve.

[Golberg]

This is correct, the first thing that triggers the pump is turning to start. The ECU doesn't prime the fuel system.