Is strong blue spark
visible at each cylinder?
malfunctioning part according to
spark test result.
18
Inspect the spark plug
conditions.
Is spark plug wet,
covered with carbon or
grayish white?
Yes
Spark plug is wet or covered
with carbon:
Inspect for fuel leakage from
injector.
Spark plug is grayish white:
Inspect the fuel injector for
clogging.
No
Install the spark plugs on
original cylinders.
Go to the next step.
19
Remove and shake the
PCV valve.
Does the PCV valve
rattle?
Yes
Go to the next step.
No
Replace the PCV valve.
20
Visually inspect the
exhaust system part.
Is there any deformed
exhaust system part?
Yes
Replace the suspected part.
No
Go to the next step.
21
Install the fuel pressure
gauge between the fuel
pipe and the fuel
distributor.
Short check connector
terminal F/P to body
GND using a jumper
wiring.
Turn the ignition switch
to the ON position.
Is fuel line pressure
correct when ignition
switch is turned on/off
five times?
(See
FUEL LINE
PRESSURE
INSPECTION [LF]
.)
Yes
Go to the next step.
No
Zero or low:
Inspect the fuel pump relay and
fuel pump circuit.
Inspect the fuel line for
clogging.
If there is no malfunction,
replace the fuel pump unit.
(See
FUEL PUMP UNIT
REMOVAL/INSTALLATION
[LF]
.)
High:
Replace the fuel pump unit.
(See
FUEL PUMP UNIT
REMOVAL/INSTALLATION
[LF]
.)
22
Visually inspect the fuel
injector O-ring and fuel
line for fuel leakage.
Service if necessary.
Is the fuel line pressure
held after the ignition
switch is turned off?
(See
FUEL LINE
PRESSURE
Yes
Go to the next step.
No
Inspect the fuel injector.
If the fuel injector is normal,
replace the fuel pump unit.
(See
FUEL PUMP UNIT
REMOVAL/INSTALLATION
[LF]
.)
2007 Mazda MX-5 Miata Sport
2007 ENGINE PERFORMANCE Symptom Troubleshooting - MX-5 Miata
Microsoft
Thursday, July 09, 2009 2:42:09 PM
Page 44
© 2005 Mitchell Repair Information Company, LLC.