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 in Preliminary Checks under Diagnosis by Symptom. Testing and Inspection
^ Make sure the driver is using the correct starting procedure.

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 ECT sensor circuit or sensor itself. Compare ECT sensor resistance value to the "Diagnostic Aids" chart on Diagnostic Trouble Code (DTC) 15 chart. Powertrain Controls - ECM/PCM
^ Check - Manifold Absolute Pressure (MAP) sensor. Does it cause a flooded condition.
^ Check - Throttle Position (TP) sensor for binding or a high TP sensor voltage with the throttle closed (should read less than 0.9 volt).

IGNITION SYSTEM
^ Check - For proper ignition voltage output with spark tester J 26792 (ST-125) or equivalent.
^ Check - Spark plugs. Remove spark plugs, check for wet plugs, cracks, wear, improper gap, burned electrodes, or heavy deposits. Spray spark plug cables with a mist of water and check for shorts. Repair or replace as necessary.
^ Check - Bare or shorted wires.
^ Check - No crank signal. Refer to Chart C-1B under C Charts. Chart C-1B Crank Signal Diagnosis
^ Check - CKT 423 for short to ground.
^ Check - Distributor pickup coil.
^ Check - Distributor bypass line.

FUEL SYSTEM
^ Check - Fuel pump relay operation - pump should turn "ON" for 2 seconds when ignition is turned "ON."
^ Check - Fuel pressure, use Chart A-7 Fuel System Diagnosis under A Charts. Related Tests, Information and Procedures
^ Check - Contaminated fuel.
^ Check - 10 amp ECM fuse.
^ Check - Excessive fuel additives.
^ Check - Injector fuse (visual inspect).
^ Check - 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 under A Charts. Related Tests, Information and Procedures
^ Check - Adequate fuel level.

NOTE: A faulty in-tank fuel pump check valve will allow the fuel to 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 under A Charts. Related Tests, Information and Procedures

ADDITIONAL CHECKS
^ Check - Idle Air Control (IAC) valve operation.
^ Check - Basic engine problem.
^ Check - Service Bulletins for updates.