Adjusting the Fuel Pressure on GM's Electronic Fuel Injection - Engine Builder Magazine

Adjusting the Fuel Pressure on GM’s Electronic Fuel Injection

By adjusting the fuel pressure you are looking for maximum
power from your new high performance engine and this will take some
trial and error to achieve. To make the adjustment you will need the following tools: A
fuel pressure gauge that will screw onto your Schrader Valve on your
fuel rail and a small wrench to turn the screw on the regulator.

Step #1 – You
will need to screw the fuel pressure gauge onto the Schrader Valve that
is located on your fuel rail, (see Figure 1) make sure that it is
tight to avoid any leaks and or fires. Once the gauge is installed turn
the ignition key to the on position and check for leaks at the Schrader

Step #2Start
the engine and let the idle level off and then disconnect the vacuum
line that goes to the regulator (see Figure 2), make sure that you
plug the rubber vacuum line so it does not leak vacuum while you are
making the adjustment, (you only care about the fuel pressure reading with the vacuum line disconnected at idle).

Step #3Take the reading and make the adjustment to 46 lbs. (see Figure 3).

Step #4You
will need to drive the vehicle and take notes as to how it is
performing, I recommend driving it for a little while so you know
exactly how the engine and vehicle react. Once you are familiar with
the engines performance adjust the fuel pressure up 2 lbs. at a time
taking notes as to the performance gain or loss and finally end your
adjustment at max power.

–Tech Tip is courtesy of Golen Engine ServiceFigure 1Figure 2Figure 3

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