The rings should fit perfectly parallel to groove surfaces.
If not, replace the piston and all the piston rings.

Piston Ring/Groove Clearance Standard:
Top 0.03
0.07 mm (0.0012
0.0028 in.)
Second 0.03
0.06 mm (0.0012
0.0024 in.)
Service Limit:
Top 0.17 mm (0.0067 in.)
Second 0.16 mm (0.0063 in.)
Piston Wear Inspection
Piston Ring Groove Width InspectionFuel Hose Replacement
Remove the fuel tank (see Fuel Tank Removal in the Fuel
System (DFI) chapter).
WARNINGFuel is flammable and explosive under
certain conditions
and can cause severe burns. Be prepared
for fuel spillage; any spilled fuel must be completely
wiped up immediately. When the fue ...
Backups
The ECU takes the following measures to prevent engine damage when the
DFI, ignition, S-KTRC
or immobilizer system parts have troubles.
Note:
(1): D-J Method: When the engine load is light like at idling or low
speed, the ECU determines the
injection quantity by calculating fr ...
Spark Plug Condition Inspection
Remove the spark plugs (see Spark Plug Replacement in
the Periodic Maintenance chapter).
Visually inspect the spark plugs.
If the spark plug center electrode [A] and/or side electrode
[B] are corroded or damaged, or if the insulator [C]
is cracked, replace the plug.
If the spark plug is ...