Hard 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 at start of Diagnosis By Symptom.

- Make sure the driver is using the correct starting procedure.

SENSORS

- CHECK: Engine coolant temperature sensor using a "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 engine coolant temperature sensor circuit or sensor itself. Compare engine coolant temperature sensor resistance value to the "Diagnostic Aids" chart on DTC 14 chart.

- CHECK: Manifold absolute pressure sensor. Check for flooding and/or correct sensor for vehicle.

- CHECK: TP sensor for binding or a high TP sensor voltage with the throttle closed (should read between 0.54 volt and 1.25 volts.)

FUEL SYSTEM

- CHECK: Fuel pump relay operation - pump should turn "ON" for 2 seconds when ignition is turned "ON". Use CHART A-5.

- CHECK: Fuel injectors are correct for the vehicle.

- CHECK: Fuel pressure, use CHART A-7.

- CHECK: Contaminated fuel.

- CHECK: Engine 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.


IGNITION SYSTEM

- CHECK: For proper ignition voltage output with spark tester J26792 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 wires.

- CHECK: Loose ignition coil ground.


ADDITIONAL CHECKS

- CHECK: Idle air control operation - use CHART C-2C.

- CHECK: Basic engine problem.

- CHECK: Service Bulletins for calibration updates.