4age bigport idle/fuel issues

[BlueLevin]

Hey guysc got a bigport that usually idles around 1500, seems a bit high but no matter how much I back the idle screw it doesn't change

also it's going through roughly 300km per tank, but only letting me fill 40 litres, only shows 3/4 tank when I fill it.

Aaaaalso on top of my intake manifold I noticed a vacuum hose that goes in a small loop into the vacuum port next to it, seen a pic of someone elses bigport and theirs went somwhere (will post pic shortly)

engines a jap spec genuine rwd bigport if this helps (dropped in an adm 86)

[Sam-Q]

have you checked if you have a fault code?

[BlueLevin]

Noob here, I'll see if I can find out how to check

[ke70dave]

you will need to hook up the check engine light to check the codes.

just grab a bulb, stick 12V on one side of it, and connect the other side to the check engine pin on your ecu.

that fuel usage is pretty damn high!

check those ecu codes, mine was doing something simliar and it turned out to be the coolant temp sensor.

[BlueLevin]

Thanks for the quick responses, I think a diy ecu check is a little out of my league, any other possibilities/checks you guys can think of?