Form 824426
Page Number - 11
10) The pump gauge should indicate 16-22” Hg .
Consult the vehicle’s service manual for a more
accurate specification . No reading or a low reading
would indicate a leaky or plugged vacuum line, or
more serious engine problem .
11) Disconnect the vacuum pump from the vacuum
line, and plug the line temporarily . Connect the
pump to the vacuum port on the regulator .
12) Use the pump to apply vacuum to the regula-
tor while watching the gauge on the fuel pressure
tester .
13) Fuel pressure should increase one pound for
every two inches of Hg vacuum applied to the regu-
lator . If not, replace the fuel pressure regulator .
Turbochargers and Superchargers
14) For forced-air induction systems (turbochargers
and superchargers) switch the pump from “Vacuum”
to “Pressure” without disconnecting it from the
regulator .
15) Use the pump to apply pressure to the regula-
tor while watching the gauge on the fuel pressure
tester .
16) Fuel pressure should increase one pound for
every one pound of pressure applied to the regula-
tor . If not, replace the fuel pressure regulator .
fueL pressure reGuLator
