929 V6-3.0L SOHC (1989)
10.
Disconnect vacuum hose from fuel pressure regulator with engine idling.
^
Fuel pressure should increase when vacuum hose is removed.
38 - 46 psi (265 - 314 kPa)
If not, replace pressure regulator.
11.
Shut engine "OFF" and wait 5 minutes, then observe residual pressure on gauge.
Minimum 21 psi (147 kPa)
If not, check for leaking fuel injectors. If injectors are not leaking, replace pressure regulator.
If all test results are OK, fuel pump and pressure regulator are OK.
