Suzuki Wagon R Manual page 3830

Diagnosis
Diagnosis Table
Refer to "Engine Diagnosis Flow Table" in Section 6-4.
Compression Check
Check compression pressure on all 4 cylinders as follows:
1) Warm up engine to normal operating temperature.
2) Stop engine after warming up.
NOTE:
After warming up engine, place transaxle gear shift lever
in "Neutral", and set parking brake and block drive
wheels.
3) Remove ignition module referring to "Ignition Module
Removal and Installation" in Section 6F4.
4) Remove all spark plugs.
5) Remove fuel pump relay (1).
6) Install special tool (compression gauge) into spark plug hole.
Special tool
(A): 09915-64512
7) Disengage clutch (to lighten starting load on engine) and
depress accelerator pedal all the way to make throttle fully
open.
(A)
8) Crank engine with fully charged battery, and read the highest
pressure on compression gauge.
9) Carry out Step 6) through 8) on each cylinder to obtain 4
readings.
NOTE:
• For measuring compression pressure, crank engine at
least 300 rpm by using fully charged battery.
• If measured compression pressure is excessively low
at one of 4 cylinder, check installation condition of spe-
cial tool. If it is properly installed, possibility is com-
pression pressure leakage from where piston ring or
valve contact.
ENGINE MECHANICAL (Z10XEP AND Z12XEP ENGINES) 6A4-3