Chart A-6 Engine Cranks But Will Not Run

Fig. 050 - Chart A-6 Engine Cranks But Will Not Run.:

Fig. 052 - WIRING DIAGRAM for Chart A-6 Engine Cranks But Will Not Run. VIN L:

CHART A-6

ENGINE CRANKS BUT WON'T RUN

3.0L "N" SERIES

FUEL INJECTION (PORT)

6. Checks for ECM control of relay through CKT 465.
7. The fuel pump control circuit includes an engine oil pressure switch with a seperate set of normally open contacts. The switch closes at about (4 lbs) 28 kPa of oil pressure and provides a second battery feed path to the fuel pump. If the relay fails, the pump will continue to run using the battery feed supplied by the closed oil pressure switch.

A failed pump 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 Will Not Run".

8. Checks the oil pressure switch to be sure it provides battery feed to the fuel pump should the pump relay rail.
9. Checks for open oil pressure switch with ignition "OFF". Should the switch stick closed, the fuel pump will continue to run and discharge the battery.