Originally posted by kylebes1
When installing an adjustible regulator what causes it to increase the output pressure as the engine accelerates? Does it "read" less back pressure on the line to the engine or what?
its connected to a vacume line that is connected to the intake manifold....when you are off the throttle that causes a high vacume condition, and pulls a diaphram in the regulator to essentially open a valve to allow pressure to drop, and when you are on open throttle that causes a low vacume condition and the "valve" closes (not letting as much fuel return to the gas tank) and causes pressure in the rail to increase.
This is essentially how all fuel pressure regulators work adjustable or not. the adjustable ones just have a screw that varries the movement of the "valve" to allow more fuel or less to pass by.