Additional Checks

This step checks the oil pressure switch to be sure it provides ignition feed to the fuel pump should the pump relay fail. A failed relay will result in extended engine crank time because of the time required to build enough oil pressure to close the oil pressure switch and turn on the fuel pump. There may be instances when the relay has failed but the engine will not crank fast enough to build enough oil pressure to close the switch. This, or a faulty oil pressure switch, can result in "engine cranks, but wont run".

Fig 1: Chart A5 Schematic, Fuel System Elect. Test (3.8L w/Standard Instrument Cluster)

Fig 2: Flow Chart A5 (1 of 2), Fuel Sys Elect Test (3.8L w/Standard Instrument Cluster)

Fig 3: Flow Chart A5 (2 of 2), Fuel Sys Elect Test (3.8L w/Standard Instrument Cluster)

This step checks the oil pressure switch to be sure it provides ignition feed to the fuel pump should the pump relay fail. A failed relay will result in extended engine crank time because of the time required to build enough oil pressure to close the oil pressure switch and turn on the fuel pump. There may be instances when the relay has failed but the engine will not crank fast enough to build enough oil pressure to close the switch. This, or a faulty oil pressure switch, can result in "engine cranks, but won't run".

Fig 1: Chart A5 Schematic, Fuel Sys Elect Test (3.8L Except w/Standard Instrument Cluster

Fig 2: Flow Chart A5 (1 of 2), Fuel Sys Elect Test (3.8L Except w/Standard Instrument Cluster

Fig 3: Flow Chart A5 (2 of 2), Fuel Sys Elect Test (3.8L Except w/Standard Instrument Cluster