Hi ,
Land cruiser 4.0l v6 1GR engine the fuel pressure regulator is connected to the airbox where it does not get vacuum.
Why the fpr is used since its not vacuum referenced. If connected to a manifold vacuum source will it affect fuel economy ?
Thanks
The fuel pressure regulator is on the fuel rail.
I think you are referring to the MAF sensor at the airbox.
It measures the air flow going through the intake as the throttle plate opens and closes.
The airflow comes through the airbox/air filter, through the intake hose, to the throttle body.
The argument for putting it farther from the throttle body, up at the air box may be that it stays cooler and cleaner.
I am referring to the fuel pressure regulator and not MAF ( my question was not clear ). the fuel pressure regulator vacuum line is not connected to the intake vacuum source. The vacuum line is connected to the airbox before the throttle where it does not get vacuum, this is how some Toyota engines FPR are connected eg. 2tr-fe, 1gr-fe found on Tacoma.
Thanks.