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."
^ 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 DTC 15 chart. Powertrain Controls - ECM/PCM
^ CHECK: 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 .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: For a loose ignition coil ground.

FUEL SYSTEM

^ CHECK: Fuel pump relay operation - pump should turn "ON" for 2 seconds when ignition is turned "ON." Use CHART A-5. Chart A-5 Fuel Pump Relay Circuit Diagnosis
^ CHECK: Fuel pressure, use CHART A-7. Related Tests, Information and Procedures
^ CHECK: Contaminated fuel.
^ 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. Related Tests, Information and Procedures
^ CHECK: Adequate fuel level.

ADDITIONAL CHECKS

^ CHECK: IAC valve operation - use CHART C-2C. Chart C-2C Idle Air Control (IAC) System Check
^ CHECK: Basic engine problem. Refer to Engine section.
^ CHECK: EGR operation - use CHART C-7. Chart C-7 EGR System Check