Chart A-5 Engine Cranks But Will Not Run

Fig. 046 - Chart A-5 Engine Cranks But Will Not Run.:

Fig. 047 - WIRING DIAGRAM for Chart A-5 Engine Cranks But Will Not Run. VIN L:

CHART A-5

ENGINE CRANKS BUT WON'T RUN

3.0L "N" SERIES

FUEL INJECTION (PORT)

When the ignition switch is turned "ON", the Electronic Control Module (ECM) will turn "ON" the in-tank fuel pump. It will remain "ON" as long as the engine is cranking or running, and the ECM is receiving HEI distributor reference pulses.
If there are no reference pulses, the ECM will shut "OFF" the fuel pump within 2 seconds after key "ON", or engine stopped.
The pump will deliver fuel to the fuel rail and injectors, then to the pressure regulator, where the system pressure is controlled to 179 to 317 kPa (26 to 46 psi). Excess fuel is then returned to the fuel tank.
The fuel pump test terminal is located in the engine compartment. When the engine is stopped, the pump can be turned "ON" by applying battery voltage to the test terminal.
Improper fuel system pressure will result in one or all of the following symptoms:
a. Cranks but won't run.
b. Code 44
c. Code 45
d. Cuts out, may feel like ignition problem.
e. Poor fuel economy, loss of power.
f. Hesitation.
1. If the fuse is blown, this test will confirm a short to ground on circuit 120. To prevent misdiagnosis, be sure fuel pump is disconnected before test.
2. Determines if the pump circuit is ECM controlled. The ECM will turn "ON" the pump relay. Engine is not cranking or running so the ECM will turn OFF" the relay within 2 seconds after ignition is turned "ON".
3. Turns "ON" the fuel pump if circuit 120 wiring is OK. If the pump runs, it is a basic fuel delivery problem which the following steps will locate.
4. Checks for battery voltage at the pump relay.
5. Checks relay ground CKT 450. Refer to Chart A-6.