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
1. Perform careful visual and physical checks as described in preliminary checks. Refer to Computers and Controls / System Diagnosis / Procedures / Diagnosis By Symptom / Preliminary Checks. Testing and Inspection
2. Make sure the driver is using the correct starting procedure.

ADDITIONAL CHECKS
1. Check the Idle Air Control (IAC) valve operation Refer to Computers and Controls / System Diagnosis / Procedures / Diagnostic Charts /Chart C-2B. Chart C-2B Idle Air Control (IAC) System Check
2. Check for basic engine problems.
3. Check Service Bulletins for updates.

SENSORS
1. Check the 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 in Diagnostic Trouble Code (DTC) 15. Powertrain Controls - ECM/PCM
2. Check the Manifold Absolute Pressure (MAP) sensor. Check for flooding.
3. Check the Throttle Position (TP) sensor for binding or a high (TP) sensor voltage with the throttle closed (should read between 0.29 volt and 0.98 volt).

IGNITION SYSTEM
1. Check For proper ignition voltage output with spark tester J 26792 or equivalent (ST-125).
2. Check Spark plugs. Remove spark plugs, check for wet plugs, cracks, wear, improper gap, burned electrodes, or heavy deposits. Repair or replace as necessary.
3. Check for bare or shorted ignition wires.
4. Check the crankshaft position sensor, resistance and connections.

FUEL SYSTEM
1. Check the Fuel pump relay operation. Pump should turn "ON" for 2 seconds when ignition is turned "ON." Refer to Computers and Controls / System Diagnosis / Procedures / Diagnostic Charts / Code 54. Powertrain Controls - ECM/PCM
2. Check the fuel pressure. Refer to Computers and Controls / System Diagnosis / Procedures / Diagnostic Charts / Chart A-7. Related Tests, Information and Procedures
3. Check for contaminated fuel.
4. Check the Fuel injector fuse.

NOTE: 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.