1A-32 Engine General Information and Diagnosis:
Engine Symptom Diagnosis
S4RS0A1104010
Perform troubleshooting referring to the followings when ECM has detected no DTC and no abnormality has been
found in “Visual Inspection: ” and “Engine Basic Inspection: ”.
Condition Possible cause Correction / Reference Item
Hard starting (Engine Faulty spark plug “Spark Plug Inspection: in Section 1H”
cranks OK) Leaky high-tension cord “High-Tension Cord Inspection: in Section 1H”
Loose connection or disconnection of “High-Tension Cord Removal and Installation:
high-tension cord(s) or lead wire(s) in Section 1H”
Faulty ignition coil “Ignition Coil Assembly (Including ignitor)
Inspection: in Section 1H”
Dirty or clogged fuel hose or pipe “Fuel Pressure Check: ”
Malfunctioning fuel pump “Fuel Pressure Check: ”
Air drawn in through intake manifold
gasket or throttle body gasket
Faulty idle air control system “Idle Air Control System Check: ”
Faulty ECT sensor or MAF sensor “Engine Coolant Temperature (ECT) Sensor
Inspection: in Section 1C” or “Mass Air Flow
(MAF) and Intake Air Temperature (IAT)
Sensor Inspection: in Section 1C”
Faulty ECM
Low compression “Compression Check: in Section 1D”
Poor spark plug tightening or faulty “Spark Plug Removal and Installation: in
gasket Section 1H”
Compression leak from valve seat “Valves and Valve Guides Inspection: in
Section 1D”
Sticky valve stem “Valves and Valve Guides Inspection: in
Section 1D”
Weak or damaged valve springs “Valve Spring Inspection: in Section 1D”
Compression leak at cylinder head “Cylinder Head Inspection: in Section 1D”
gasket
Sticking or damaged piston ring “Cylinders, Pistons and Piston Rings
Inspection: in Section 1D”
Worn piston, ring or cylinder “Cylinders, Pistons and Piston Rings
Inspection: in Section 1D”
Malfunctioning PCV valve “PCV Valve Inspection: in Section 1B”
Camshaft position control (VVT) system “Oil Control Valve Inspection: in Section 1D”
out of order
Faulty EGR system “EGR System Inspection: in Section 1B”
Low oil pressure Improper oil viscosity “Engine Oil and Filter Change: in Section 0B”
Malfunctioning oil pressure switch “Oil Pressure Switch Inspection: in Section
9C”
Clogged oil strainer “Oil Pan and Oil Pump Strainer Cleaning: in
Section 1E”
Functional deterioration of oil pump “Oil Pump Inspection: in Section 1E”
Worn oil pump relief valve “Oil Pump Inspection: in Section 1E”
Excessive clearance in various sliding
parts
Engine noise – Valve Improper valve lash “Camshaft, Tappet and Shim Inspection: in
noise Section 1D”
Worn valve stem and guide “Valves and Valve Guides Inspection: in
NOTE:
Section 1D”
Before checking Weak or broken valve spring “Valve Spring Inspection: in Section 1D”
mechanical noise, make Warped or bent valve “Valves and Valve Guides Inspection: in
sure that: Section 1D”
• Specified spark plug is
used.
• Specified fuel is used.