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Engine Cranks, But Will Not Run













Wiring Diagram:






Circuit Description
Battery voltage is applied to the ignition coil when the ignition switch is turned to the ON or START positions. The ignition control module toggles the primary windings of the ignition coil in order to induce a high voltage in the secondary windings of the ignition coil. The powertrain control module (PCM) commands the ignition control module based on numerous inputs including the camshaft position sensor. The high voltage induced in the secondary windings of the ignition coil is applied through the distributor cap and rotor to the spark plugs.

Diagnostic Aids
Check for any of the following conditions: The fuel injectors may spray fuel, but not enough fuel to start the engine. Check the engine coolant temperature (ECT) sensor reading with a scan tool. The indicated temperature should be close to the actual engine temperature in order for the PCM to deliver the correct amount of fuel.
^ Check TP sensor reading with a scan tool. The TP sensor reading should be 7-18% (0.42-1.15 volts) with the throttle closed.
^ Check the battery condition and the engine cranking speed. The engine will not start and improper diagnosis may occur if the starting system is not operating to necessary levels. Refer to Starting and Charging.
^ Water or foreign material can cause a no start during freezing weather. The engine may start after 5 or 6 minutes in a heated shop. The malfunction may not recur until parked overnight in freezing temperatures.
^ Low fuel pressure can result in a very lean air/fuel mixture which may be difficult to ignite. Refer to Fuel System Diagnosis. System Diagnosis - Fuel System
^ Fouled or damaged spark plugs will cause an Engine Cranks But Will Not Run condition. Refer to Ignition System.
^ A vehicle that starts and runs after being brought to the shop for an Engine Cranks But Will Not Run complaint, may have an ignition system that is susceptible to moisture. Spray water on the ignition system components and wiring in order to check for an engine miss or stall.
^ Check for a malfunctioning main relay. A faulty main relay can cause no MIL and an engine that cranks but will not run.
^ Check for a faulty IG COIL METER fuse.
^ A short to ground in the BRN/WHT wire between the noise suppressor filter and the distributor could cause a no start condition, also check the resistance of the noise suppressor filter. Refer to Ignition System.
An intermittent malfunction may be caused by a problem in the ignition system electrical circuit. Inspect the wiring harness and components for any of the following conditions:
^ Backed out terminals.
^ Improper mating of terminals.
^ Broken electrical connector locks.
^ Improperly formed or damaged terminals.
^ Faulty terminal to wiring connections.
^ Physical damage to the wiring harness.
^ Broken conductor inside the wire insulation.
^ Corrosion of electrical connections, splices, or terminals.

Test Description
The numbers below refer to the step numbers in the Diagnostic Table.
1. The Powertrain OBD System Check prompts the technician to complete some basic checks and store the freeze frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
2. If a DTC P0340 is set, go to the DTC P0340 table first. P0340 If a problem still exists, continue diagnosis with the Engine Cranks But Will Not Run table.
3. Checks for spark at the spark plugs.
5. Checks for faulty Ignition wires.
8. Checks the power and ground circuits to the distribution
9. Checks the power and ground circuits to the distributor. If the Ignition feed circuit is found not to have the proper voltage, check the Main relay (other symptoms should be noticed).
10. Checks the primary circuit of the Ignition Coil which is located in the distributor.
11. Checks the secondary circuit of the Ignition Coil which is located in the distributor
12. Remove the orange retaining cap inside the connector and remove the terminal. Do not allow the wire removed to touch ground, allow the wire to hang freely. After cranking the engine over and returning the ignition switch to the run position, the DMM voltage reading will rise to about 12 volts and than return to 0 volts this should be considered normal operation.
13. After cranking the engine over and returning the ignition switch to the run position, the DMM voltage reading will rise to about 12 volts and than return to 0 volts this should be considered normal operation.