Hard to Start

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-2BChart C-2B 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 DTC 15chart.

^ 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 .29 volt and .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 Diagnostic Trouble Code (DTC) 54.DTC 54
^ CHECK: Fuel pressure, use CHART A-7Related 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.