Mazda MX-6 1998, Workshop Manual

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TROUBLESHOOTING [ENGINE CONTROL FS]
1 0
ENGINE STALLS/QUITS (ACCELERATION/CRUISE)
ENGINE RUNS ROUGH (ACCELERATION/CRUISE)
MISSES (ACCELERATION/CRUISE)
BUCK/JERK (ACCELERATION/CRUISE/DECELERATION)
HESITATION/STUMBLE (ACCELERATION)
SURGES (ACCELERATION/CRUISE)
DESCRIPTION
• Engine stops unexpectedly at beginning of or during acceleration
• Engine stops unexpectedly while cruising
• Engine speed fluctuates during or cruising
• Engine misses during acceleration or cruising
• Vehicle bucks/jerks during acceleration, cruising or deceleration
• Momentary pause at beginning of acceleration or during acceleration
• Momentary minor irregularity in engine output
POSSIBLE
CAUSE
• A/C system improperly operation
• Air leak from intake air system parts
• Improper operation of IAC valve
• Erratic signal from crankshaft position sensor
• Vacuum leaks
• Spark leak from hightension leads
• PCV valve malfunction
• Restriction in exhaust system
• Inadequate fuel pressure
• Fuel leak from fuel injector
• Intermittent open or short of mass-airflow sensor, throttle position sensor and vehicle speed sensor
• Automatic transaxle malfunction
• Erratic signal or no signal from camshaft position sensor
• Purge solenoid valve malfunction
• EGR valve malfunction
• Low engine compression
• Poor fuel quality
• Air cleaner restriction
• Improper valve timing due to jumping out timing belt
• Intermittently open/short in fuel pump circuit
• Fuel pump mechanical malfunction
• Fuel injector clogged
• Clutch slippage
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.
cr
0 1 -1 4 BEFORE REPAIR PROCEDURE
zr 0 1 -1 4 AFTER REPAIR PROCEDURE
STEP INSPECTION
ACTION
1
Verify following:
• Vacuum connection.
• Air cleaner element.
• No air leaks from intake air system.
• No restriction of intake air system.
• Proper sealing of intake manifold and
components attached to intake manifold:
EGR valve, IAC valve.
• Ignition wiring.
• Fuel quality:
Proper octane, contamination,
winter/summer blend.
• Electrical connections.
Are all items okay?
Yes Go to next step.
No
Service as necessary and repeat step 1.
2
Retrieve and record any continuous memory,
KOEO and KOER DTCs. If stall, condition
exists retrieve continuos memory and
KOEO
DTCs.
Are there any DTCs displayed?
Yes Go to appropriate DTC test.
No Go to next step.
01-01 A—143