ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-81
TROUBLESHOOTING
Step Action Yes No
1 Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE” in this
section.
2 Ignition system inspection :
1) Check spark plug and ignition spark of cylin-
der where misfire occurs, referring to “IGNI-
TION SYSTEM” section.
Is it in good condition?Go to Step 3. Faulty ignition coil, wire
harness, or other system
parts.
3 Fuel injector circuit inspection :
1) Using sound scope, check each injector
operating sound at engine cranking or
idling.
Do all injectors make operating sound?Go to Step 4. Check coupler connec-
tion and wire harness of
injector not making oper-
ating sound and injector
itself.
If OK, substitute a known-
good ECM (PCM) and
recheck.
4 Fuel pressure inspection :
1) Check fuel pressure referring to “TABLE B-
3” in this section.
Is check result satisfactory?Go to Step 5. Repair or replace.
5 Fuel injector inspection :
1) Check fuel injector(s) referring to Section
6E2.
Is check result satisfactory?Go to Step 6. Replace.
6 Ignition timing inspection :
1) Check ignition timing referring to Section
6F2.
Is check result satisfactory?Go to Step 7. Adjust or check system
related parts.
7 EGR system inspection :
1) Check EGR system referring to Section
6E2.
Is check result satisfactory?Go to Step 8. Repair or replace.
8 Fuel level sensor inspection :
1) Check fuel level sensor referring to Section
6E2.
Is check result satisfactory?Go to Step 9. Repair or replace.
9 Check engine mechanical parts or system
which can cause engine rough idle or poor per-
formance.
• Engine compression (See Section 6A2).
• Valve lash or lash adjuster (See Section
6A2).
• Valve timing (Timing belt or chain installa-
tion. See Section 6A2).
Are they in good condition?Check wire harness and
connection of ECM (PCM)
ground, ignition system
and fuel injector for inter-
mittent open and short.Repair or replace.
