Hard to Start

DEFINITION
ENGINE cranks OK but does not start for a long time. Does eventually run, or may start but immediately dies.

PRELIMINARY CHECKS
^ Perform the careful visual/physical checks as described at start of "Symptoms,".
^ Make sure the driver is using the correct starting procedure.

ADDITIONAL CHECKS
^ CHECK: IAC valve operation - see Chart C-2C Idle Air Control (IAC) Valve Check. Under Diagnostic Charts/C Charts. Chart C-2C Idle Air Control (IAC) System Check
^ CHECK: Basic engine problem.
^ CHECK: Service Bulletins for updates.

SENSORS
^ CHECK: Engine Coolant Temperature (ECT) sensor using a Tech 1 scan tool, compare engine coolant temperature with ambient temperature on cold engine.

- If engine coolant temperature readings are 5 degrees greater than or less than ambient air temperature on a cold engine, check resistance in engine coolant temperature sensor circuit or sensor itself. Compare ECT sensor resistance value to the "Diagnostic Aids" chart on Diagnostic Trouble Code (DTC) 15 Coolant Temp. Sensor Circuit (Low Temp). Under DTC Charts/PCM Diagnostic Trouble Codes. Powertrain Controls - ECM/PCM

^ CHECK: MAP sensor. Check for flooding.
^ CHECK: Throttle Position (TP) sensor for binding or a high Throttle Position (TP) sensor voltage with the throttle closed (should read between 0.29 volt and 0.98 volt).

IGNITION SYSTEM
^ CHECK: For proper ignition voltage output with spark tester J 26792 or equivalent (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 shorted ignition wires.
^ CHECK: Crankshaft position sensor, resistance and connections.

FUEL SYSTEM
^ CHECK: Fuel pump relay operation. Pump should turn "ON" for 2 seconds when ignition is turned "ON." Use Chart A-5 Fuel Pump
Relay Circuit Diagnosis. Under Diagnostic Charts/A-Charts.
^ CHECK: Fuel pressure, use CHART A-7 Fuel System Diagnosis. Under Diagnostic Charts/A Charts. Related Tests, Information and Procedures
^ CHECK: Contaminated fuel.
^ CHECK: Fuel injector fuse.

NOTICE: 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 fuel system diagnosis CHART A-7.