Hard start (4JJ3 without DPD)

1. Hard start description of symptom

The engine cranks but does not start for an extended period of time. The engine does eventually run, or may start but immediately stops.

2. Hard start diagnostics

1. Preliminary inspection

Perform the Diagnostic system check - engine controls.
Perform the Fuel supply pump functional inspection.
Verify that the driver is using the correct starting procedure.
Ensure that the ground of the ECM is free of dirt and is fixed securely in the correct position.
Inspect whether the harness connector is properly connected.
Inspect the fuel type and quality.
Verify the injector ID code of each cylinder.
Check the scan tool data list.
Check for related Service Bulletins.

2. Sensor inspection

Compare the Engine Coolant Temperature (ECT), Intake Air Temperature (IAT), and Fuel Temperature parameters while the engine is cold. If the difference between the temperature values is 5°C {9°F} or more when the engine is cold, inspect for high resistance in each circuit and for a sensor malfunction.
{When the ignition switch is turned ON, the MAF sensor is heated, and as a result, the IAT shows a higher value than the normal intake air temperature.}
Observe the Fuel Rail Pressure (FRP) Sensor parameter on the scan tool. It is normal if the Fuel Rail Pressure (FRP) Sensor parameter shows approximately 20 MPa or more when the ignition switch is turned ON without starting the engine after the engine operation is stopped. If not, inspect for high resistance in each circuit and for a sensor malfunction.
The CKP sensor is securely installed, and the sensor rotor is not damaged.
The CMP sensor is securely installed, and the timing chain sprocket is not damaged.

3. Fuel system inspection

Inspect for air in the fuel system.
Inspect for water in the fuel.
Inspect the fuel for being frozen.
Inspect whether the fuel filter warning light illuminates intermittently or frequently.
Inspect the fuel filter for clogging.
Inspect for external fuel leakage and excessive engine oil.
Inspect for fuel leakage from the injector.
Inspect for collapsing, twisting, improper tightening, cracking, or clogging in the fuel system between the fuel tank and the fuel supply pump.
Inspect the vent valve and hose of the fuel tank for clogging.
{The piping may be clogged due to foreign material from the fuel tank entering the fuel system.}
Inspect the operation of the fuel supply pump.
{The fuel supply pump must be timed with the engine, and the adjusted value should be learned by the ECM.}
Perform the Injector Cutoff with a scan tool.

4. Air intake system inspection

Inspect the air cleaner, air intake duct, and intercooler for clogging, holes, or leakage.
Inspect for any condition that restricts flow within the turbocharger intake duct.
Inspect for a stuck intake throttle valve.
Inspect for clogging or leakage in the inlet manifold.

5. Exhaust system inspection

Inspect whether the exhaust system flow is restricted.

6. Engine mechanical inspection

Inspect the compression pressure of the engine.
Inspect for improper idle gear timing.
Inspect the valve clearance.
Inspect the valve spring for breakage and fatigue.
Inspect the camshaft for wear.
Inspect the ring gear for wear.
Inspect the internal engine for seizure.

7. Electrical system inspection

Inspect the glow plug control system operation.
Inspect the cranking speed.
Inspect the battery for deterioration.