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 the 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 engine coolant sensor circuit or sensor itself. Compare ECT sensor resistance value to the "Diagnostic Aids" in DTC P0117 chart. Testing and Inspection

Check the 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 volt and 0% throttle angle).

FUEL SYSTEM
Check the fuel pump relay operation - pump should turn "ON" for 2 seconds when ignition is turned "ON." Refer to Chart A-5. Testing and Inspection
Check Fuel pressure, use Chart A-7. Testing and Inspection
Check For contaminated fuel and sufficient fuel quantity.
Check the injector fuse (visual inspect).

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. Testing and Inspection

IGNITION SYSTEM
Check for proper ignition voltage output with spark tester J 26792 (ST 123) or equivalent
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 wires.
Check for loose ignition control module ground (mounting screws).

ADDITIONAL CHECKS
Check Idle air Control (IAC) valve operation - use Chart C-2B. Testing and Inspection
Check for basic engine problem.
Check Service Bulletins for PROM updates.
Check for crankcase ventilation valve stuck open.