Hard to Start

PRELIMINARY CHECKS
^ Perform the visual and physical checks as described under Preliminary Checks.
^ Make sure the driver is using the correct starting procedure.

SENSORS
Check: Engine Coolant Temperature (ECT) sensor using a scan tool, compare ECT with ambient temperature on a cold engine. If ECT reading is either 5 degrees greater or less than ambient air temperature on a cold engine, check resistance in engine coolant sensor circuit or sensor itself. Compare ECT resistance value to the "Diagnostic Aids" chart in Diagnostic Trouble Code (DTC) 15. Powertrain Controls - ECM/PCM

Check: Manifold Absolute Pressure (MAP) sensor, Refer to Chart C-1D MAP Output Check. Chart C-1D Manifold Absolute Pressure (MAP) Output Check

Check: Mass Air Flow (MAF) sensor installation. A MAF sensor that is installed backwards can cause a rich condition. A malfunctioning MAF sensor may cause a no start or hard start.

Check: Throttle Position (TP) sensor for binding or a high TP sensor voltage with the throttle closed. The TP sensor voltage should read between 0.3 and 0.9 volt at closed throttle.

FUEL SYSTEM
Check: Fuel pump relay operation. The pump should turn "ON" for 2 seconds when ignition is turned "ON." Refer to Chart A-5 Fuel Pump Relay Circuit. Chart A-5 Fuel Pump Relay Circuit Diagnosis

Check: Fuel pressure. Refer to Chart A-7 Fuel System Diagnosis. Related Tests, Information and Procedures

Check: Contaminated fuel.

Check: Both injector fuses (visual inspect).

NOTE: A faulty in-tank fuel pump check valve will allow the fuel in the lines to drain back to the tank after engine is stopped. To check for this condition, perform Chart A-7 Fuel System Diagnosis. Related Tests, Information and Procedures

IGNITION SYSTEM
Check: For proper ignition voltage output with spark tester J26792 (ST 125).

Check: Spark Plugs. Remove spark plugs, check for wet plugs, cracks, wear, improper gap, burned electrodes, or heavy deposits. Repair or replace as necessary.

Check: Bare or shortened ignition wires.

Check: Loose ignition coil ground.

Check: Coil fuse.

Check: Distributor vent system. Refer to Chart C-4C Distributor Vent System Check. Chart C-4C Distributor Vent System Check

ADDITIONAL CHECKS
Check: Idle Air Control (IAC) operation using Chart C-2C Idle Air Control Valve Check. Chart C-2C Idle Air Control (IAC) System Check

Check: Basic engine problem.

Check: PROM calibration I.D. for most current and/or incorrect software. Refer to PROM - Programmable Read Only Memory for calibration information.