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Home >> Isuzu Truck >> 1995 >> Rodeo (4WD) V6-3165cc 3.2L SOHC (6VD1) >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Symptom Related Diagnostic Procedures >> Hard Start

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 in Preliminary Checks.
Preliminary Checks

- 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 reading 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 Diagnostic Trouble Code (DTC) 14 Chart.
DTC 14

CHECK: Manifold Absolute Pressure Sensor. Check for flooding and/or correct sensor for Vehicle.

CHECK: Throttle Position (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". See Diagnostic Charts / Chart A-5.
A - Charts

CHECK: Fuel Injectors are correct for the Vehicle.
CHECK: Fuel Pressure, see Diagnostic Charts / Chart A-7.
A - Charts

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 see Diagnostic Charts / Chart A-7.
A - Charts

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, see Diagnostic Charts / Chart C-2C.
C - Charts

CHECK: Basic Engine problem.

IGNITION SYSTEM
CHECK: For proper Ignition voltage output with Spark Tester J26792 or equivalent.

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