Chart A - 3 Engine Cranks But Won't Run 3.0L ('85) "N" Series Fuel Injection (Port): Overview

Ignition System Wiring Diagram:

CONDITION: Engine cranks but won't run, or Engine may start, but immediately stops running. Battery condition and engine cranking speed are OK and there is adequate fuel in the tank.

This engine is equipped with distributorless ignition system called "Computer Controlled Coil Ignition" (C3I). The EST and Bypass circuits operate in the same manner as in an HEI system.
1. A "SERVICE ENGINE SOON" light is "ON" is a basic check for ignition and battery supply to the Electronic Control Module (ECM).

2. Checks to see if the ECM is controlling the fuel injectors. A blinking test light at this point indicates the ECM is controlling the injectors and that ignition reference signal to the ECM is good.

3. Checks to see if problem is fuel or ignition related.

4. Checks to see if fuel pump and relay are operating correctly. Fuel pump should run for only 2 seconds after ignition "ON".

5. An injector driver circuit shorted to ground would result in the test light on steady and possibly a flooded engine. A shorted injector (less than 10 OHMS) could have caused an ECM failure.

6. Checks for ignition feed to injectors on each bank.

7. Checks to see if ECM is receiving reference signal from ignition system.
DIAGNOSTIC AIDS.

Check For:

- Open coolant sensor.

- EGR sticking open.

- TPS binding or sticking in wide open throttle position.

- Water or foreign material in fuel.

- A defective MAF Sensor may cause a no start or a stall after start. To determine if the sensor is causing the problem, disconnect it. The ECM will then use a default value for the sensor, and if the condition is corrected and the connections are OK, replace the sensor.

Engine Diagnosis Chart:

CHART A-3

ENGINE CRANKS BUT WILL NOT RUN

3.0L ('85) "N" SERIES

FUEL INJECTION (PORT)