Suzuki Wagon R Manual page 2175

6A2-8 ENGINE MECHANICAL (M13 ENGINE)
(C)
Diagnosis
Diagnosis Table
Refer to "Engine and Emission Control System Check" in Section
6-2.
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" (shift selector lever to "P" range for A/T
model), and set parking brake and block drive wheels.
3) Disconnect ignition coil couplers (1).
4) Remove ignition coil assemblies (2) with high-tension cord
(3).
5) Remove all spark plugs.
6) Disconnect fuel injector wires (4) at the coupler.
7) Install special tools (compression gauge) into spark plug
(A) hole.
Special tool
(B)
(A): 09915-64512
(B): 09915-64530
(C): 09915-67010
8) Disengage clutch (1) (to lighten starting load on engine) for
M/T vehicle, and depress accelerator pedal (2) all the way to
make throttle fully open.
9) Crank engine with fully charged battery, and read the highest
pressure on compression gauge.