Mazda MX-6 1998, Workshop Manual

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TROUBLESHOOTING [ENGINE CONTROL KL]
26
EXHAUST SULPHUR SMELL
DESCRIPTION
Rotten egg smell (sulphur) from exhaust
Note
• Some slight sulphur smell may be normal. Catalyst with less than 8,000— 1 6,000 km {5,000 to 1 0,000
miles} mileage is likely to have sulphur smell concern due to highly active state of new catalysts.
Replacing catalyst if no problem is found may actually make symptom worse.
POSSIBLE
CAUSE
• Electrical connectors disconnected or poor connection
• Vacuum lines disconnected or improper connection
• Charcoal canister malfunction
• Improper fuel pressure
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 leaks 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.
oy 0 1 -1 4 BEFORE REPAIR PROCEDURE
EF 0 1 -1 4 AFTER REPAIR PROCEDURE
STEP INSPECTION
ACTION
1 Are any drivability or exhaust smoke concern
present?
Yes Go to appropriate flow chart.
No
Go to next step.
2 Check following:
• Electrical connections.
• Vacuum lines.
Are all items okay?
Yes Go to next step.
No Service as necessary.
Repeat step 2.
3 Retrieve and record any continuous memory,
KOEO and KOER DTCs.
Are there any DTCs displayed?
Yes Go to appropriate DTC test.
No
Go to next step.
4
Install fuel pressure gauge between fuel filter
and fuel delivery pipe.
Start engine and run it at idle.
Is fuel line pressure correct at idle?
Fuel line pressure
210— 260 kPa
{2.1— 2.6 kgf/cm2, 30— 37 psi}
Yes Go to next step.
No Zero or low:
Check fuel pump circuit.
Check for open fuel pump relief valve.
Check for fuel leak inside pressure regulator.
Check for clogged main fuel line.
High:
Check pressure regulator for high pressure cause.
Check for clogged fuel return line.
5 Does fuel line pressure remain at specification
for 60 seconds when ignition switch is turned
ON?
Fuel line pressure
210— 260 kPa
{2.1— 2.6 kgf/cm2, 30— 37 psi}
Yes Go to next step.
No Check pressure regulator for high pressure cause.
6
Check charcoal canister for fuel saturation.
Is excess amount of liquid fuel present in
canister?
Yes Replace charcoal canister.
No Check fuel tank vent system.
If fuel tank vent system is okay:
Since sulphur content can vary In different fuels, suggest
trying different brand.
If fuel tank vent system is not okay:
Repair or replace malfunctioning part.
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