Fuel Pressure question.

[mattasi]

Hello I am in the process of upgrading some fuel components. I just did the rewire on the 255 fuel pump, so now I am trying to get the pressure back to where it was before the rewire. My question here is this...When I am messing around with the fuel pressure regulator I can change the fuel pressure from lets say 45-60psi and it doesn't affect what my wideband is reading...is that normal? Seems like if I raised the fuel pressure that the car would be running rich, but the wideband is dead on 14.7 at idle. Does the fuel pressure not affect the air/fuel ratio as much at idle or something?

 

[lil corb]

You have to look at your short term, long term fuel trim and combined fuel trim to see how much fuel is being added or taken away as the ecu will try and shoot for 14.7 during closed loop operation no matter what.

 

[mattasi]

Ok perfect, thank you. I am going to have the whole thing retuned after all the fuel upgrades but was just really curious why nothing changed the wideband reading.

 

[mattasi]

Where do I find these short term, long term fuel trim and combined fuel trims? Looking through Link I don't see that anywhere.