Troubleshooting¶

Engine overheating¶

Problem	Possible cause	Remedy	Page
Engine overheats	Cooling system faulty	Troubleshoot cooling system	CO-4
	Incorrect ignition timing	Reset timing	Installation of distributor

Problem	Possible cause	Remedy	Page
Engine will not crank or cranks slowly	Starting system faulty	Troubleshoot starting system	Troubleshooting
Engine will not start / hard to start (cranks OK)	No fuel supply to injector No fuel in tank Fuel pump no working Fuel filter clogged Fuel line clogged or leaking	Troubleshoot EFI system	FI-11
	EFI system problems	Repair as necessary
	Ignition problems Ignition coil Igniter Distributor	Perform spark test	On-vehicle inspection (3S-GTE)
	Spark plug faulty	Inspect plugs	Inspection of high-tension cords
	High-tension cords disconnected or broken	Inspect cords	Inspection of high-tension cords
	Vacuum leaks PCV line EGR line Intake manifold T-VIS valve (3S-GTE) Throttle body ISC valve Brake booster line	Repair as necessary
	Air suction between air flow meter and throttle body	Repair as necessary
	Low compression	Check compression	Compression check

Problem	Possible cause	Remedy	Page
Rough idle, stalls or misses	Spark plug faulty	Inspect plugs	Inspection of high-tension cords
	High-tension cord faulty	Inspect cords	Inspection of high-tension cords
	Ignition problems Ignition coil Igniter Distributor	Inspect coil Inspect igniter Inspect distributor	Inspection of spark plugs Inspection of distributor Inspection of distributor
	Incorrect ignition timing	Reset timing	Installation of distributor
	Vacuum leaks PCV line EGR line Intake manifold T-VIS valve (3S-GTE) Throttle body ISC valve Brake booster line	Repair as necessary
	Air suction between air flow meter and throttle body	Repair as necessary
	Incorrect idle speed	Check ISC system	FI-148, 151
	Incorrect valve clearance	Adjust valve clearance	Inspection and adjustment of valve clearance (3S-GTE)
	EFI system problems	Repair as necessary
	Engine overheats	Check cooling system	CO-4
	Low compression	Check compression	Compression check

Problem	Possible cause	Remedy	Page
Engine hesitates / poor acceleration	Spark plug faulty	Inspect plug	Inspection of high-tension cords
	High-tension cord faulty	Inspect cords	Inspection of high-tension cords
	Vacuum leaks PCV line EGR line Intake manifold T-VIS valve Throttle body ISC valve Brake booster line	Repair as necessary
	Air suction between air flow meter and throttle body	Repair as necessary
	Incorrect ignition timing	Reset timing	Installation of distributor
	Incorrect valve clearance	Adjust valve clearance	Inspection and adjustment of valve clearance (3S-GTE)
	Fuel system clogged	Check fuel system
	Air cleaner clogged	Check air cleaner	Maintenance operations
	EFI system problems	Repair as necessary
	Emission control system problem (cold engine) EGR system always on	Check EGR system	EC-8, 24
	Engine overheats	Check cooling system	CO-4
	Low compression	Check compression	Compression check

Problem	Possible cause	Remedy	Page
Engine diesels (runs after ignition switch is turned off)	EFI system problems	Repair as necessary
	Incorrect ignition timing	Reset timing	Installation of distributor
	EGR system faulty	Check EGR system	EC-8, 24

Problem	Possible cause	Remedy	Page
Muffler explosion (after fire) on deceleration only	Deceleration fuel cut system always off	Check EFI (fuel cut) system
Muffler explosion (after fire) all the time	Air cleaner clogged	Check air cleaner	Maintenance operations
	EFI system problem	Repair as necessary
	Incorrect ignition timing	Reset timing	Installation of distributor
Engine backfires	EFI system problem	Repair as necessary
	Vacuum leak PCV line EGR line Intake manifold T-VIS valve Throttle body ISC valve Brake booster line	Check hoses and repair as necessary
	Air suction between air flow meter and throttle body	Repair as necessary
	Insufficient fuel flow	Troubleshoot fuel system	FI-11
	Incorrect ignition timing	Reset timing	Installation of distributor
	Incorrect valve clearance	Adjust valve clearance	Inspection and adjustment of valve clearance (3S-GTE)
	Carbon deposits in combustion chambers	Inspect cylinder head	Inspection, cleaning and repair of cylinder head components

Problem	Possible cause	Remedy	Page
Excessive oil consumption	Oil leak	Repair as necessary
	PCV line clogged	Check PCV system
	Piston ring worn or damaged	Check rings	Removal of engine
	Valve stem and guide bushing worn	Check valves and guide bushing	Inspection, cleaning and repair of cylinder head components
	Valve stem oil seal worn	Check seals

Problem	Possible cause	Remedy	Page
Poor gasoline mileage	Fuel leak	Repair as necessary
	Air cleaner clogged	Check air cleaner	Maintenance operations
	Incorrect ignition timing	Reset timing	Installation of distributor
	EFI system problems Injector faulty Deceleration fuel cut system faulty	Repair as necessary
	Idle speed too high	Check ISC system	FI-148, 151
	Spark plug faulty	Inspect plugs	Inspection of high-tension cords
	EGR system always on	Check EGR system	EC-8, 24
	Low compression	Check compression	Compression check
	Tires improperly inflated	Inflate tire to proper pressure
	Clutch slips	Troubleshoot clutch
	Brakes drag	Troubleshoot brakes

Problem	Possible cause	Remedy	Page
Unpleasant odor	Incorrect idle speed	Check ISC system	FI-148, 151
	Incorrect ignition timing	Reset timing	Installation of distributor
	Vacuum leaks PCV line EGR line Intake manifold T-VIS valve Throttle body ISC valve Brake booster line	Repair as necessary
	EFI system problems	Repair as necessary