NO.13 KNOCKING/PINGING/DETONATION-ACCELERATION/CRUISE


13	KNOCKING/PINGING/DETONATION - ACCELERATION/CRUISE
DESCRIPTION	A sound is produced when the air/fuel mixture is ignited by something other than the spark plug (e.g., hot spot in combustion chamber).
POSSIBLE CAUSE	• Air suction at intake-air system • Poor fuel quality • Inadequate fuel pressure • Pressure regulator (integrated in fuel pump unit) malfunction • Fuel pump relay stuck closed • Fuel injector malfunction (clogging, lack of injection amount) • Erratic signal from eccentric shaft position sensor • Improper ignition timing control (ECT, IAT, MAF and knock signals to PCM) • Incorrect spark plug heat range • Improper operation of eccentric shaft bypass valve • Engine overheating due to cooling system malfunction • Excessive carbon is built up in combustion chamber • Inadequate engine compression – Engine internal malfunction – Abnormal engine oil condition (viscosity, deterioration) – Low oil pressure – Excessive fuel pressure – Air mixed in oil pipe – Metering oil pump malfunction • Leakage or clogging in oil pipe • Leakage or clogging in oil nozzle Warning The following troubleshooting flow chart contains fuel system diagnosis and repair procedures. Read the following warnings before servicing the fuel system: • Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel. • Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete "BEFORE REPAIR PROCEDURE" and "AFTER REPAIR PROCEDURE" described in this manual. (See BEFORE REPAIR PROCEDURE.) (See AFTER REPAIR PROCEDURE.) Caution • Disconnecting/connecting quick release connector without cleaning it may possibly cause damage to fuel pipe and quick release connector. Always clean quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.


STEP	INSPECTION	RESULTS	ACTION
1	Inspect air suction between MAF sensor and intake-port. Is there any air suction?	Yes	Repair or replace the air suction at the intake-air system.
1		No	Go to the next step.
2	Connect the WDS or equivalent to the DLC-2. Access the ECT PID. Verify that the ECT PID is less than 116°C {241°F} during driving. Is the ECT PID less than the specification?	Yes	Go to the next step.
2		No	Inspect the cooling system for the cause of overheating.
3	Connect the WDS or equivalent to the DLC-2. Access the IAT, the MAF and the SPARKADV PIDs. Monitor each PID. (See PCM INSPECTION.) Are the PIDs normal?	Yes	Go to the next step.
3		No	IAT PID: Inspect the IAT sensor. (See INTAKE AIR TEMPERATURE (IAT) SENSOR INSPECTION.) MAF PID: Inspect the MAF sensor. (See MASS AIR FLOW (MAF) SENSOR INSPECTION.) SPARKADV PID: Inspect the eccentric shaft position sensor and the knock sensor. (See ECCENTRIC SHAFT POSITION SENSOR INSPECTION.) (See KNOCK SENSOR (KS) INSPECTION.)
4	Connect the WDS or equivalent to the DLC-2. Retrieve any continuous memory, KOEO and KOER DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the applicable DTC inspection. (See DTC TABLE.)
4		No	No DTC is displayed: Go to the next step.
5	Perform the fuel pump speed control operation inspection. (See Fuel Pump Speed Control Operation Inspection.) Does the fuel pump speed control operate properly?	Yes	Go to the next step.
5		No	Repair or replace the malfunctioning parts, according to the fuel pump speed control operation inspection results.
6	Is a strong blue spark visible at each disconnected high-tension lead while cranking the engine?	Yes	Inspect for the following: • Spark plugs malfunction • Spark plugs heat range • Pulse wheel damaged on eccentric shaft • Open or short circuit on the eccentric shaft position sensor • Open or short circuit between the eccentric shaft position sensor and PCM terminal 2U or 2X If they are normal, go to the next step.
6		No	Inspect for the following: • High-tension leads • Ignition coils or connectors
7	Inspect the knock sensor. (See KNOCK SENSOR (KS) INSPECTION.) Is the knock sensor normal?	Yes	Go to the next step.
7		No	Replace the knock sensor. (See KNOCK SENSOR (KS) REMOVAL/INSTALLATION.)
8	Inspect the engine compression. (See COMPRESSION INSPECTION.) Is it normal?	Yes	Go to Step 14.
8		No	Go to the next step.
9	Perform the metering oil pump control inspection. (See Metering Oil Pump Control Inspection.) Does the metering oil pump control operate properly?	Yes	Go to the next step.
9		No	Repair or replace the malfunctioning part according to the inspection results. After that overhaul or replace the engine. (See Engine Workshop Manual.)
10	Check the engine oil condition. Is the engine oil low viscosity and/or is there a gasoline odor?	Yes	Replace the engine oil. Inspect the ECT sensor and the related wiring harnesses. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION.) After that overhaul or replace the engine. (See Engine Workshop Manual.)
10		No	Go to the next step.
11	Inspect the oil pressure. (See OIL PRESSURE INSPECTION.) Is the oil pressure within the specification?	Yes	Go to the next step.
11		No	Repair or replace the malfunctioning part according to the inspection results. After that overhaul or replace the engine. (See Engine Workshop Manual.)
12	Turn the ignition switch off. Disconnect the fuel line quick release connector and install the fuel gauge to the fuel line. Start the engine and run it at idle. Measure the fuel line pressure at idle. Is the fuel line pressure correct at idle? (See FUEL LINE PRESSURE INSPECTION.)	Yes	Go to the next step.
12		No	Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION.) After that overhaul or replace the engine. (See Engine Workshop Manual.)
13	Check the oil pipe between the metering oil pump and the metering oil nozzle. Is there any air and/or clogging in the oil pipe?	Yes	Inspect and repair for leakage and/or clogging in the oil passage at the engine. After that overhaul or replace the engine. (See Engine Workshop Manual.)
13		No	Overhaul or replace the engine. (See Engine Workshop Manual.)
14	Install the fuel pressure gauge to the fuel line quick release connector. Start the engine and run it at idle. Measure the fuel line pressure at idle. Is the fuel line pressure correct at idle? (See FUEL LINE PRESSURE INSPECTION.)	Yes	Go to the next step.
14		No	Zero or low: Inspect for clogged fuel line. If normal, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION.) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION.)
15	Inspect the fuel injectors for the following: • Clogging • Injection amount (See FUEL INJECTOR INSPECTION.) Are the injectors normal?	Yes	Go to the next step.
15		No	Replace the fuel injector. (See FUEL INJECTOR REMOVAL/INSTALLATION.)
16	Inspect the ignition timing. (See Ignition Timing Inspection.) Does the ignition timing operate properly?	Yes	Inspection the eccentric bypass valve operation. (See Engine Workshop Manual.)
16		No	Repair or replace the malfunctioning parts, according to the ignition timing inspection results.
17	Verify test results. • If normal, return to the diagnostic index to service any additional symptoms. • If the malfunction remains, inspect the related Service Information and perform the repair or diagnosis.