CHART A3 (1 of 2) - ENGINE CRANKS, BUT WON'T RUN (5.0/5.7L)

This chart assumes that battery condition and engine cranking speed are okay, and there is adequate fuel in the tank.

1. A "SERVICE ENGINE SOON" light, is a basic test to determine if there is 12 volts to the ECM. No ALDL may be due to an ECM problem and CHART A2 will diagnose the ECM. If TPS is over 2.5 volts, the engine may be in the "Clear Flood" mode, which will cause starting problems. The engine will not start without reference pulses and, therefore, the "SCAN" tester should read RPM (reference) while cranking.
2. No spark may be caused by one of several components related to the ignition system. CHART C4 will cover all problems related to the causes of a no spark condition.
3. The test light should blink, indicating the ECM is controlling the injectors okay. How bright the light blinks is not important.
4. Using Fuel Pressure Gauge (J 34730 1), wrap a shop towel around the fuel pressure tap to absorb any small amount of fuel leakage that may occur when installing the gauge.