Toyota 4A-FE Repair Manual page 27

EM-38
4A-FE
ENGINE MECHANICAL - Compression Check
COMPRESSION CHECK
HINT: If there is lack of power, excessive oil consump-
tion or poor fuel economy, measure the compression
pressure.
1.
WARM UP AND STOP ENGINE
2.
DISCONNECT COLD START INJECTOR CONNECTOR
3.
DISCONNECT DISTRIBUTOR CONNECTOR(S)
4. {4A-GE)
REMOVE PLUG CORD COVER
6. REMOVE SPARK PLUGS (See page IG-7, 11)
6.
CHECK CYLINDER COMPRESSION PRESSURE
{a) Insert a compression gauge into the spark plug hole.
(b)
Fully open the throttle.
(c)
While cranking the engine, measure the compression
pressure.
HINT: Always use a fully charged battery to obtain
engine revolution of 250 rpm or more.
{d) Repeat steps (a) through (c) for each cylinder.
NOTICE: This measurement must be done in as short
a time as possible.
Compression pressure:
4A-FE 13.5 kg/cm
2
(191
psi,
1,320 kPal
Minimum pressure:
10.0 kg/cm 2 (142 psi, 981 kPal
Difference between each cylinder:
1.0 kg/cm2 (14 psi, 98 kPa) or less
(e) If the cylinder compression in one or more cylinders
is low, pour a small amount of engine oil into the
cylinder through the spark plug hole and repeat steps
(a) through (c) for the cylinder with low compression.
• If adding oil helps the compression, chances are
that the piston rings and/or cylinder bore are worn
or damaged.
• If pressure stays low, a valve may be sticking or
seating improperly, or there may be leakage past
the gasket.
7. REINSTALL SPARK PLUGS {See page IG-8, 12)
Torque: 180 kg-cm (13 ft-lb, 18 N·m)
8.
9. RECONNECT DISTRIBUTOR CONNECTOR(S)
10. RECONNECT COLD START INJECTOR CONNECTOR