NO.8 ENGINE RUNS ROUGH/ROLLING IDLE [LF]
POSSIBLE CAUSE & DESCRIPTION (ENGINE RUNS ROUGH/ROLLING IDLE [LF])
indicates cold range but
ECT PID is normal,
inspect temperature
gauge and heat gauge
unit.
3
Is throttle body free of
contamination?
Yes
Inspect for air leakage
from the intake-air
system components
while racing the engine
to higher speed.
No
Clean or replace
throttle body.
4
Verify test results.
If normal, return to diagnostic index to service any additional
symptoms.
(See
ENGINE SYMPTOM TROUBLESHOOTING [LF]
.)
If malfunction remains, inspect related Service Bulletins and/or On-
line Repair 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.
(See
PCM REMOVAL/INSTALLATION [LF]
.)
8
ENGINE RUNS ROUGH/ROLLING IDLE
DESCRIPTION
Engine speed fluctuates between specified
idle speed and lower speed and engine shakes
excessively.
Idle speed is too slow and engine shakes
excessively.
Air leakage from intake-air system parts
A/C system operation is improper
Erratic signal to ignition coil
Spark plug malfunction
Purge solenoid valve malfunction
Improper operation of electronic throttle
control system
2007 Mazda MX-5 Miata Sport
2007 ENGINE PERFORMANCE Symptom Troubleshooting - MX-5 Miata
Microsoft
Thursday, July 09, 2009 2:42:09 PM
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