SERVICE MANUAL NUMBER 23
FUEL INJECTION SYSTEM TROUBLESHOOTING
Page 5D-17
90-861326--1 MARCH 1999
Detonation/Spark Knock Symptom (Continued)
5
1. Check for good ignition system
ground.
2. Check spark plugs for proper gap
and heat range.
3. If a problem is found, repair as
necessary.
Was a problem found?
-
Go to OBD
System
Check
Go to Step 6
6
1. Check for contaminated fuel.
2. Check for poor fuel quality and
proper octane rating.
3. If a problem is found, repair as
necessary.
Was a problem found?
-
Go to OBD
System
Check
Go to Step 7
7
1. Check for proper fuel pressure.
•
Refer to Table A-4 in “General Sys-
tem Diagnostics” section.
2. If a problem is found, repair as
necessary.
Was a problem found?
-
Go to OBD
System
Check
Go to Step 8
8
Is a scan tool being used?
-
Go to Step 9
Go to Step 10
9
If scan tool readings are normal (
Refer
to “Scan Tool Normal Specifications” in
this section) and there are no engine
mechanical faults, fill fuel tank with a
known high quality gasoline.
Is detonation present?
-
Go to Step
10
Go to OBD
System Check
10
1. Check for obvious overheating
problems:
•
Loose water pump belt.
•
Faulty or incorrect water pump.
•
Restriction in cooling system.
•
Faulty or incorrect thermostat.
2. If a problem is found, repair as
necessary.
Was a problem found?
-
Go to OBD
System
Check
Go to Step 11
11
1. Check fuel delivery system items
that can cause an engine to run lean.
2. If a problem is found, repair as nec-
essary.
Was a problem found?
-
Go to OBD
System
Check
Go to Step 12
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