1997 SUBARU LEGACY fuel consumption

1. Engine Trouble in General
Numbers shown in the chart refer to the possibility of reason for the
trouble in order (“Very often”to“Rarely”)
1—Very often
2—Sometimes
3—Rarely
TROUBLE
Engine will not start.
Rough idle and engine stall
Low output, hesitation and poor acceleration
Surging
Engine does not return to idle.
Dieseling (Run-on)
After burning in exhaust system
Knocking
Excessive engine oil consumption
Excessive fuel consumption Starter does not turn.
Initial combustion does not occur.
Initial combustion occurs.
Engine stalls after initial combustion.
POSSIBLE CAUSE
STARTER
2Defective battery-to-starter harness
3Defective starter switch
3Defective inhibitor switch
23Defective starter
BATTERY
1Poor terminal connection
1Run-down battery
2Defective charging system
1111111111 1Fuel injection system Diagnostics II System.>
75
2-3DIAGNOSTICS
1. Engine Trouble in General

TROUBLE
Engine will not start.
Rough idle and engine stall
Low output, hesitation and poor acceleration
Surging
Engine does not return to idle.
Dieseling (Run-on)
After burning in exhaust system
Knocking
Excessive engine oil consumption
Excessive fuel consumption Starter does not turn.
Initial combustion does not occur.
Initial combustion occurs.
Engine stalls after initial combustion.
INTAKE SYSTEM
2111 3Loosened or cracked intake air pipe
3111 3 1Loosened or cracked blow-by hose
31211 2Loosened or cracked vacuum hose
22222Defective intake manifold gasket
22222Defective throttle body gasket
322 2 2Defective PCV valve
222 323Loosened oil filler cap
3312 1Dirty air cleaner element
FUEL LINE
13 322Defective fuel pump and relay
33322Clogged fuel line
222233Lack of or insufficient fuel
BELT
222Defective
222322 22 2Defective timing
FRICTION
3Seizure of crankshaft and connecting rod bearing
3Seized camshaft
3Seized or stuck piston and cylinder
COMPRESSION
333222 23 2Incorrect valve clearance
333223 3 3Loosened spark plugs or defective gasket
333223 3 3Loosened cylinder head bolts or defective gasket
333223 2 2Improper valve seating
333333 3 13Defective valve stem
222223 3 3Worn or broken valve spring
333233 3 12Worn or stuck piston rings, cylinder and piston
222111 12 2Incorrect valve timing
222222Improper engine oil (low viscosity)
76
2-3DIAGNOSTICS
1. Engine Trouble in General

TROUBLE
Engine will not start.
Rough idle and engine stall
Low output, hesitation and poor acceleration
Surging
Engine does not return to idle.
Dieseling (Run-on)
After burning in exhaust system
Knocking
Excessive engine oil consumption
Excessive fuel consumption Starter does not turn.
Initial combustion does not occur.
Initial combustion occurs.
Engine stalls after initial combustion.
LUBRICATION SYSTEM
22 3 3Incorrect oil pressure
2Loosened oil pump attaching bolts and defective
gasket
2Defective oil filter seal
2Defective crankshaft oil seal
32Defective rocker cover gasket
2Loosened oil drain plug or defective gasket
2Loosened oil pan fitting bolts or defective oil pan
COOLING SYSTEM
33221Overheating
333Over cooling
OTHERS
113 3Malfunction of Evaporative Emission Control
System
21Stuck or damaged throttle valve
322 2Accelerator cable out of adjustment
77
2-3DIAGNOSTICS
1. Engine Trouble in General

1. Engine Trouble in General
Numbers shown in the chart refer to the possibility of reason for the
trouble in order (“Very often”to“Rarely”)
1—Very often
2—Sometimes
3—Rarely
TROUBLE
Engine will not start.
Rough idle and engine stall
Low output, hesitation and poor acceleration
Surging
Engine does not return to idle.
Dieseling (Run-on)
After burning in exhaust system
Knocking
Excessive engine oil consumption
Excessive fuel consumption Starter does not turn.
Initial combustion does not occur.
Initial combustion occurs.
Engine stalls after initial combustion.
POSSIBLE CAUSE
STARTER
2Defective battery-to-starter harness
3Defective starter switch
3Defective inhibitor switch
23Defective starter
BATTERY
1Poor terminal connection
1Run-down battery
2Defective charging system
1111111111 1Fuel injection system Diagnostics II System.>
77
2-3bDIAGNOSTICS
1. Engine Trouble in General

TROUBLE
Engine will not start.
Rough idle and engine stall
Low output, hesitation and poor acceleration
Surging
Engine does not return to idle.
Dieseling (Run-on)
After burning in exhaust system
Knocking
Excessive engine oil consumption
Excessive fuel consumption Starter does not turn.
Initial combustion does not occur.
Initial combustion occurs.
Engine stalls after initial combustion.
INTAKE SYSTEM
2111 3Loosened or cracked intake air pipe
3111 3 1Loosened or cracked blow-by hose
31211 2Loosened or cracked vacuum hose
22222Defective intake manifold gasket
22222Defective throttle body gasket
322 2 2Defective PCV valve
222 323Loosened oil filler cap
3312 1Dirty air cleaner element
FUEL LINE
13 322Defective fuel pump and relay
33322Clogged fuel line
222233Lack of or insufficient fuel
BELT
222Defective
222322 22 2Defective timing
FRICTION
3Seizure of crankshaft and connecting rod bearing
3Seized camshaft
3Seized or stuck piston and cylinder
COMPRESSION
333222 23 2Incorrect valve clearance
333223 3 3Loosened spark plugs or defective gasket
333223 3 3Loosened cylinder head bolts or defective gasket
333223 2 2Improper valve seating
333333 3 13Defective valve stem
222223 3 3Worn or broken valve spring
333233 3 12Worn or stuck piston rings, cylinder and piston
222111 12 2Incorrect valve timing
222222Improper engine oil (low viscosity)
78
2-3bDIAGNOSTICS
1. Engine Trouble in General

TROUBLE
Engine will not start.
Rough idle and engine stall
Low output, hesitation and poor acceleration
Surging
Engine does not return to idle.
Dieseling (Run-on)
After burning in exhaust system
Knocking
Excessive engine oil consumption
Excessive fuel consumption Starter does not turn.
Initial combustion does not occur.
Initial combustion occurs.
Engine stalls after initial combustion.
LUBRICATION SYSTEM
22 3 3Incorrect oil pressure
2Loosened oil pump attaching bolts and defective
gasket
2Defective oil filter seal
2Defective crankshaft oil seal
32Defective rocker cover gasket
2Loosened oil drain plug or defective gasket
2Loosened oil pan fitting bolts or defective oil pan
COOLING SYSTEM
33221Overheating
333Over cooling
OTHERS
113 3Malfunction of Evaporative Emission Control
System
21Stuck or damaged throttle valve
322 2Accelerator cable out of adjustment
79
2-3bDIAGNOSTICS
1. Engine Trouble in General

tity is determined by the duration of an electric pulse
applied to the fuel injector and this permits simple, yet
highly precise metering of the fuel.

Further, all the operating conditions of the engine are
converted into electric signals, and this results in additional
features of the system, such as large improved
adaptability, easier addition of compensating element, etc.
The MFI system also has the following features:
1) Reduced emission of harmful exhaust gases.
2) Reduced in fuel consumption.
3) Increased engine output.
4) Superior acceleration and deceleration.
5) Superior startability and warm-up performance in cold
weather since compensation is made for coolant and
intake air temperature.
3
2-7ON-BOARD DIAGNOSTICS II SYSTEM
1. General