6F-4
IGNITION SYSTEM
DIAGNOSIS
Condition
Possible Cause
Correction
Engine cranks, but will
not start or hard to start
Blown fuse for ignition coil
Loose connection or disconnection of lead wire or
high-tension cord(s)
Faulty high-tension cord(s)
Faulty spark plug(s)
Cracked rotor or cap
Maladjusted signal rotor air gap
Faulty ignition coil
Faulty noise suppressor
Faulty CMP sensor
Faulty igniter
Faulty ECM
Maladjusted ignition timing
Replace
Connect securely
Replace
Adjust, clean or replace
Replace
Adjust
Replace
Replace
Replace
Replace
Replace
Adjust
Poor fuel economy or
engine performance
Incorrect ignition timing
Faulty spark plug(s) or high-tension cord(s)
Faulty ECM
Adjust
Adjust, clean or replace
Replace
DIAGNOSTIC FLOW TABLE
STEP
ACTION
YES
NO
1
Was ENGINE DIAGNOSTIC FLOW TABLE in SEC-
TION 6 performed?
Go to Step 2.
Go to ENGINE DIAG-
NOSTIC FLOW
TABLE in SECTION 6.
2
Ignition Spark Test
1) Check all spark plug for condition and type, refer-
ring to SPARK PLUG in this section.
2) If OK, perform ignition spark test, referring to IGNI-
TION SPARK TEST in this section.
Is spark emitted from all spark plugs?
Go to Step 11 on the
next page.
Go to Step 3.
3
Diagnostic Trouble Code (DTC) Check
1) Check DTC stored in ECM, referring to DIAGNOS-
TIC TROUBLE CODE (DTC) CHECK in SECTION
6E1.
Is DTC stored?
Go to applicable flow
table corresponding to
that code No. in SEC-
TION 6E1.
Go to Step 4.
4
Electrical Connection Check/Noise Suppressor Check
1) Check ignition coil for electrical connection.
2) Check noise suppressor referring to NOISE SUP-
PRESSOR.
Are they in good condition?
Go to Step 5.
Connect securely.
Replace noise sup-
pressor.
5
High-tension Cord Check
1) Check high-tension cord for resistance, referring to
HIGH-TENSION CORDS in this section.
Is check result satisfactory?
Go to Step 6.
Replace high-tension
cord(s).
6
Igniter Check
1) Check igniter, referring to IGNITER in this section.
Is check result satisfactory?
Go to Step 7.
Replace igniter.
