Warm Engine Control Pressure Test
- Connect pressure gauge and 3-way valve assembly as in cold engine control pressure test. Tester valves "A" and "B" must be open. With fuel pumps activated, control pressure should be as specified in WARM ENGINE CONTROL PRESSURE TEST table.
- If pressure is incorrect, check manifold vacuum. Disconnect vacuum hose from control pressure regulator. Install "T" fitting and vacuum gauge into line. Note vacuum reading and compare readings with intake vacuum/control pressure graph. See Fig 1.WARM ENGINE CONTROL PRESSURE TEST (1)
Application Pressure psi (kg/cm2 ) 1976 Models 49-55 (3.4-3.8) 1977-78 Models Federal 49-55 (3.4-3.8) Calif. 42-48(2.9-3.3) High Alt 52-58 (3.6-4.0) 1979 Models 49-55 (3.4-3.8) (1) With manifold vacuum at 11.8 in. Hg. If manifold vacuum is higher, pressure will be slightly lower. If manifold vacuum is lower, pressure will be slightly higher. See Fig 1. - Unplug connector and check voltage at control pressure regulator with engine running. Voltage should be minimum of 13.5 volts. With ignition off, check regulator heating coil with ohmmeter. Reading should be about 35 ohms. If not, replace control pressure regulator.
- To check full-load enrichment, remove vacuum line from control pressure regulator. Pressure should drop to 41-46 psi (2.8-3.2 kg/cm2 ). If not, replace regulator.