Mazda MX-6 1998, Workshop Manual

Page: 258 / 1282

TROUBLESHOOTING [ENGINE CONTROL KL]
STEP INSPECTION ACTION
9 CHECK FUEL INJECTOR FOR FLOW AND
LEAKAGE
• Verify that flow rate for each fuel injector is
within specification using SST (49 L018
901).
• Is flo w rate fo r each fu e l in je c to r w ith in
s p e c ific a tio n ?
Yes Fuel delivery system Is not likely to have caused Misfire
DTC.
Go to next step.
No REPLACE or CLEAN inoperative fuel injector(s) as
required.
RESET PCM to completely clear DTCs.
tr After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
10 CHECK VACUUM SYSTEM
• Inspect all vacuum lines for damage, such
as pinched lines, cracks, proper routing
and component.
• Is v e h ic le vacuum system okay?
Yes Go to next step.
No SERVICE vacuum system.
RESET PCM to completely clear DTCs.
ty After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
11 CHECK EVAPORATIVE EMISSION SYSTEM
Misfire Monitor can be influenced by
Evaporative Emission System. Steps 11-14
will diagnose Evaporative emission system.
• Check charcoal canister for fuel saturation.
• Is th e re an excess a m o u n t o f liq u id fuel
p re se n t in charcoal canister.
Yes REPLACE charcoal canister.
RESET PCM to completely clear DTCs.
ty After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No Go to next step.
12
CHECK VACUUM IN EVAPORATIVE
EMISSION SYSTEM
• Check for blockage/restriction or cut hoses
between engine vacuum port and charcoal
canister.
• Check for blockage in fuel tank vent
system.
• Is th e re fa u lt in d ica ted ?
Yes REPLACE damaged vacuum hoses, or REMOVE
blockage/restrictions.
RESET PCM to completely clear DTCs.
ty
After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No Go to next step.
13 CHECK PURGE SOLENOID VALVE
This step will verify mechanical integrity of
purge solenoid valve. Solenoid and circuit
have been checked electrically and reported
during key on engine off (KOEO) Self-Test.
• Key off.
• Disconnect purge solenoid valve.
• Connect 12 volt DC power source to
solenoid.
C aution
• M ust be o b se rve d fo r p ro p e r pin
o rie n ta tio n .
• Connect positive power source to power
circuit and negative lead to purge solenoid
valve circuit at purge solenoid valve
harness connector.
• Apply 53 kPa {407 mmHg, 16 inHg) of
vacuum to manifold side of purge solenoid
valve. Apply power source.
• Does s o le n o id open and pass a ir fre e ly?
Yes
Evaporative system is functioning properly.
Go to next step for base engine concerns.
No
REPLACE purge solenoid valve.
RESET PCM to completely clear DTCs.
ty After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
14 CHECK FOR BASE ENGINE CONCERNS
Purpose of this step is to determine if there
are any Base Engine concerns that may have
caused Misfire DTC or drive concern.
Perform following tests in order to evaluate
Base Engine integrity.
• Perfom an Engine Compression test.
• Perform Dynamic Valve train analysis.
• Check Positive Crankcase Ventilation
System.
• Check possible leakage points.
p - 01 —1 OB COMPRESSION INSPECTION
[KL]
• is a n y se rv ic e requ ire d ?
Yes SERVICE as necessary.
RESET PCM to completely clear DTCs.
mr After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No
Cause of Misfire DTC is intermittent and diagnosis will be
in Ignition System.
Check intermittent poor connection or component
malfunction (SERVICE or REPLACE as necessary),
or 01-18 IGNITION SYSTEM INSPECTION
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