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 visual/physical checks as described at start of Preliminary Checks.
^ Make sure the driver is using the correct starting procedure.

SENSOR CHECKS
^ 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 is 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.
^ Manifold Absolute Pressure (MAP) sensor. Does it cause a flooded condition.
^ 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 CHECKS
^ 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. Spray spark plug cables with a mist of water and check for shorts. Repair or replace as necessary.
^ For a loose ignition coil ground.

FUEL SYSTEM CHECKS
^ Fuel pump relay operation - pump should turn "ON" for 2 seconds when ignition is turned "ON." Use CHART A-5.
^ Fuel pressure, use CHART A-7.
^ Contaminated fuel.
^ Injector fuse (visual inspect).
^ 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.
^ Adequate fuel level.

ADDITIONAL CHECKS
^ Idle Air Control (IAC) valve operation - use CHART C-2C.
^ Basic engine problem. Refer to SECTION 6A.
^ Exhaust Gas Recirculation (EGR) operation - use CHART C-7.