Mazda 626 Station Wagon, Workshop Manual

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TROUBLESHOOTING
STEP
INSPECTION ACTION
4 • Inspect com pression pressure at
suspected faulty cylinder.
• Is compression pressure correct?
(See Section B)
Yes Go to next step.
No Repair or replace malfunctioning part.
5 • Install all spark plugs.
• Carry out spark test at suspected
faulty cylinder.
• Is strong blue spark visible? (Compare
with normal cylinder.)
Yes Go to next step.
No Repair or replace malfunctioning parts.
6 • Carry out fuel line pressure inspection.
(See Section F)
• Is fuel line pressure correct?
Yes Inspect fuel injector for following:
• Open or short circuit in injector
• Leakage
• Injection volume
No
Zero or low:
• Inspect fuel pump circuit.
• Inspect for open fuel pump relief valve.
• Inspect fo r fuel leakage inside pressure
regulator.
• Inspect for clogged main fuel line.
• Inspect pulsation damper
High:
• Inspect pressure regulator for high pressure
cause.
• Inspect for clogged fuel return line.
7 • Inspect spark plug for following.
— Heat range
— A ir gap
• Is spark plug okay?
Yes Go to next step.
No Replace spark plug.
8 • Remove suspected fuel injector.
• Inspect following:
— Resistance
(See Section F)
— Fuel injection volum e
(See Section F)
• Are all above items okay?
Yes
Inspect for open circuit between suspected fuel injector
connector terminal and following PCM connector terminals:
• For #1 cylinder: 75
• For #2 cylinder: 101
• For #3 cylinder: 74
• For #4 cylinder: 100
No Replace fuel injector.
9
• Is air cleaner elem ent free of
restriction?
Yes Go to next step.
No Replace air cleaner element.
10 • Carry out spark test.
• Is strong blue spark visible at each
cylinder?
Yes Go to next step.
No Repair or replace malfunctioning part.
11 • Carry out fuel line pressure inspection.
• Is fuel line pressure correct?
Fuel line pressure
210—260 kPa {2.1—2.6 kgf/cm2, 30—36 psi>
Yes Go to next step.
No Zero or low:
• Inspect fuel pump circuit.
• Inspect for open fuel pump relief valve.
• Inspect for fuel leakage inside pressure
regulator.
• Inspect for clogged main fuel line.
High:
• Inspect pressure regulator for high pressure
cause.
• Inspect for clogged fuel return line.
12 • Inspect following PIDs.
- E C T
— ECT V
F H 0 2 S or 0 2 S II
- M A F
- M A F V
• Are PIDs okay?
Yes Go to next step.
No Repair or replace malfunctioning parts.
13 • Carry out purge control inspection
(when engine can be started).
• Is purge control correct?
Yes Go to next step.
No Repair or replace malfunctioning part.
14 • Carry out compression inspection.
• Is com pression correct?
Yes Inspect for clogging in exhaust system.
No Repair or replace malfunctioning part.
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