Mazda 626 Station Wagon, Workshop Manual

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TROUBLESHOOTING
NQ.19 FUEL ODOR (IN ENGINE COMPARTMENT)
19
Fuel odor (in engine compartment)
DESCRIPTION • Gasoline fuel smell or visible leakage.
POSSIBLE
CAUSE
• Excessive fuel pressure
• Fuel tank vent system blockage
• Charcoal canister malfunction
Warning
• Following troubleshooting flow chart contains fuel system diagnosis and repair
procedures. Read following warnings before performing fuel system service:
— 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”. (See
Section F)
Caution
• Disconnecting/connecting the quick release connector without cleaning it may possibly
cause damage to the fuel pipe and quick release connector. Always clean the quick
release connector joint area before disconnecting/connecting, and make sure that it is
free of foreign material.
Diagnostic Procedure
STEP INSPECTION RESULTS ACTION
1
Visually inspect for fuel leakage at fuel injector
O-ring and fuel line.
Service as necessary.
Install fuel pressure gauge between fuel main pipe
and fuel distributor.
Start engine and run it at idle.
Then stop engine.
Does fuel line pressure remain within specification
for 60 seconds when ignition switch is turned on
and off?
Fuel line pressure
260—310 kPa {2.6—3.2 kgf/cm2, 37—46 psi}
Yes
Go to next step.
No
Inspect pressure regulator for high pressure
cause.
2 Inspect for blockage/restriction or open between
engine vacuum port and charcoal canister.
Inspect for blockage in fuel tank vent system.
Is fault indicated?
Yes Replace vacuum hose.
No Go to next step.
3 Inspect purge solenoid valve.
(See Section F)
Is solenoid operating properly? Yes Go to next step.
No Replace purge solenoid valve.
4 Connect NGS tester to DLC.
Turn ignition switch on.
Retrieve any DTC.
Is any DTC displayed?
Yes DTC is displayed:
Go to appropriate DTC test.
No No DTC is displayed:
Inspect charcoal canister for fuel saturation.
If excessive amount of liquid fuel present,
replace charcoal canister.
5 Verify test results. If okay, return to diagnostic index to service any additional symptoms.
F1-137