Fuel Pressure Reg. ?

[We Gone]

Thanks Chris, Great explanation.

I also ask Marc H about this this was his reply.

Removing the vacuum line from the fuel pressure regulator adds 8 psi
of fuel pressure at low engine loads. This will add about 10% more
fuel at idle. Over about 10 minutes of run time the engine control
system will compensate by removing the excess fuel. This can improve
operation if the fuel injectors have a low flow problem. Either dirty
from cheap fuel or shorted solenoid coils due to ethanol damage.
Beyond about 50% throttle removing the vacuum line has no effect
because the engine vacuum is low enough to increase the fuel pressure
normally with the hose attached. The fuel pressure at idle is 43 psi.
At WOT it's 43 + 8 = 51 psi.

Best regards.

Marc