TROUBLE DIAGNOSES
Symptom Matrix Chart (Cont'd)
RELATION BETWEEN TROUBLE SYMPTOMS AND ENGINE MECHANICAUACCESSORIES
Malfunction of the gasoline engine will not occur when the three elements of combustion (compression
pressure, aidfuel mixture, and spark) are all normal. Though the
aidfuel mixture and the spark (ignition tim-
ing) are controlled by ECM
(.TCM) control unit, if the engine mechanical is malfunctioning,
a malfunction will
occur. (The table below shows universal cases. Some cases may not apply to the vehicle.)
Engine mechanical-related malfunction
0: High possibility 0: Medium possibility A: Low posstbility
I No I Hard
start start
I Air sucked in at oil level gauge
Air sucked in at oil filler cap
Loose air duct
(A-F/M downstream) 0 A
Misconnection of canister piping
0 A
Cracked intake manifold
0 A
Aidfuel
mix-
ture
PCV valve stuck open
Clogged fuel strainer
0 A
Clogged air cleaner element
Malfunctioning pressure regulator
A 0 0 0
Improper gasoline properties A000
EGR valve stuck open 0 0
Deposits on valve 0 0
Excessive canister purge volume
Misconnection of high-tension wire
Improperly adjusted ignition timing
Malfunctioning spark plug
High-tension wire leaks
A000
Spark Distributor cap leaks
A000
Compres-
Improper valve contact
sion pres-
. a080
sure Worn piston ring ~080
Others
Clogged catalytic converter or
exhaust system A00
Low base idle speed A
A
Foreign material (vinyl, etc.) in fuel 1 tank
Clogged radiator or capacitor
IIII
Rough idle I Poor drivability Engine stall
- - - - - - -- ': Fast
idle
Adding to the items listed above, check the following.
Wiring harness for tension Ground wires for loosenes nuids and oils for levels All connectors for connection Battery connections for loosenes and corrosion Drive belts for loosenes
