Question about vacuum and afpr tuning.

[adam355]

Basically what I am wondering is when you set your fuel pressure at idle, does it set to your current vacuum reading? So if your at different vacuum readings will you have different fuel pressure? Because I'll set my fuel pressure at idle and when I am decelerating and the vacuum reading is higher the fuel pressure also gets lower. Thanks

 

[steve]

Basically what I am wondering is when you set your fuel pressure at idle, does it set to your current vacuum reading?
So if your at different vacuum readings will you have different fuel pressure?

When you set your base pressure you do so with the vacuum line removed from the FPR and the line plugged so you don't have a vacuum leak. Once you put the line back on, the pressure should drop the same psi as your vacuum in inches of mercury converted to psi.

Fuel pressure = Base Pressure + manifold pressure (- for vacuum, + for boost)

Steve