Subaru IMPREZA 2002 Service Manual page 189

ENGINE TROUBLE IN GENERAL
MECHANICAL
Loosened or cracked intake duct
Loosened or cracked PCV hose
Loosened or cracked vacuum hose
Defective intake manifold aasket
TROUBLE
A
A
A
B
2. Rough idle and engine
stall
Fuel line
PROBLEM PARTS, ETC:
I
Dirty air cleaner element
C
Defective fuel pump and relay C
Cloaaed fuel line C
POSSIBLE CAUSE
Loosened spark plugs or defective gasket
Loosened cylinder head bolts or defective gasket
ImDroDer valve seatina
I
RANK
B
B
B
Engine control system <Ref. to EN(S0HC)-2, Basic Diagnostic Procedure.>
I A
Lubrication system
Intake system
Incorrect valve timing A
Improper engine oil
(low
viscosity) B
Incorrect oil pressure B
Defective rocker cover aasket C
Stuck or damaged throttle valve
Accelerator cable out of adjustment
1
Defective throttle body gasket
I B
B
C
I
Defective PCV valve
I C
I
Loosened oil filler cap
I B
I
Lack of or insufficient fuel
I B
Belt
I
Defective timing I C
Compression
I
incorrect valve clearance
I B
I
Defective valve stem
I C
I
Worn or broken valve spring
I B
I
Worn or stuck piston rings, cylinder and piston
I B
Coolina system
I
Overheating I C
Others
I
Malfunction of evaporative emission control system
I
A
ME(S0HC)-91