Hard to Start

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

SENSORS
Check:
^ Engine Coolant Temperature (ECT) sensor using a Tech 1, compare engine coolant temperature with Intake Air Temperature (IAT) on cold engine.
^ If engine coolant temperature readings are 5 degrees greater than or less than intake air temperature on a cold engine, check resistance in coolant sensor circuit or sensor itself. Compare ECT sensor resistance value to the Diagnostic Aids table on DTC P0117 chart. P0117
^ Throttle Position (TP) sensor for binding or a high TP sensor voltage with the throttle closed (should read between 0.2 volt and 0.74 volts and 0% throttle angle).

FUEL SYSTEM
Check:
^ Fuel pump relay operation - pump should turn "ON" for 2 seconds when ignition is turned "ON." Use Chart A-5 Fuel System Electrical Test. Chart A-5 Fuel System Electrical Test

^ Fuel pressure, use Chart A-7 Fuel System Diagnosis. Related Tests, Information and Procedures

^ For contaminated fuel or sufficient fuel quantity.


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 Fuel System Diagnosis. Related Tests, Information and Procedures


IGNITION SYSTEM
Check:
^ For proper ignition voltage output with spark tester J 26792 (ST 125) or equivalent
^ Spark plugs. Remove spark plugs, check for wet plugs, cracks, wear, improper gap, burned electrodes, or heavy deposits. Repair or replace as necessary.
^ Bare or shorted wires.
^ Loose ignition control module ground (mounting screws).

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

^ Basic engine problem.
^ Service Bulletins for PROM updates.
^ Positive Crankcase Ventilation ([1][2]PCV) valve stuck open.