NO.12 KNOCKING/PINGING-ACCELERATION/CRUISE [F2]

id010394850500

12

KNOCKING/PINGING - ACCELERATION/CRUISE
DESCRIPTION
Sound is produced when air/fuel mixture is ignited by something other than spark plug (e.g. hot spot in combustion chamber).
POSSIBLE CAUSE
•  Engine overheating due to cooling system malfunction
•  Inadequate engine compression
•  Inadequate fuel pressure
Warning
•  The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services:
―  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 the “BEFORE SERVICE PRECAUTION” and “AFTER SERVICE PRECAUTION” described in this manual.

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION
1
Connect the M-MDS to the DLC-2.
Access ECT PID.
Verify ECT PID is less than 116°C {241°F} during driving.
Is ECT PID less than specification?
Yes
Go to the next step.
No
Inspect cooling system for cause of overheating.
2
Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON position (Engine off).
Retrieve any DTCs.
Are there any DTCs displayed?
Yes
DTC is displayed:
•  Go to appropriate the DTC inspection.
No
No DTC is displayed:
•  Inspect instrument cluster operation.
3
Is engine compression correct?
(See COMPRESSION INSPECTION [F2].)
Yes
Go to the next step.
No
Inspect for cause.
4
Install fuel pressure gauge between the fuel main pipe and the fuel distributor.
Start engine and idle it.
Measure fuel line pressure during idle.
Is fuel line pressure correct during idle?
(See FUEL PUMP UNIT INSPECTION [F2].)
Yes
Go to the next step.
No
Zero or low:
Inspect the fuel pump circuit.
Inspect for the open fuel pump relief valve.
Inspect for the fuel leakage inside pressure regulator.
Inspect for the clogged main fuel line.
High:
Inspect the pressure regulator for high pressure cause.
Inspect for the clogged fuel return line.
5
Install vacuum gauge to intake manifold.
Start engine.
Does fuel pressure gauge reading increase as vacuum gauge reading decreases and/or does fuel pressure gauge reading decrease as vacuum reading increases?
Yes
Inspect ignition timing.
No
Connect vacuum hose to pressure regulator.
Start engine.
Verify that fuel pressure gauge reading changes as vacuum changes.
If it changes, inspect vacuum line.
If it does not change, replace pressure regulator.
6
•  Verify test results.
―  If normal, return to diagnostic index to service any additional symptoms.
―  If malfunction remains, inspect related Service Information and perform repair or diagnosis.
•  If vehicle is repaired, troubleshooting completed.
•  If vehicle is not repaired or additional diagnostic information is not available, replace the PCM.