If the surface is corroded or if the blades are damaged, replace the impeller

Water Pump Impeller Disassembly/Assembly
Water Pump Housing DisassemblyConnecting Rod Big End
Bearing Insert/Crankpin Wear Inspection
Remove the connecting rod big end (see Connecting Rod
Removal).
Cut strips of plastigage to crankpin width. Place a strip
on the crankpin parallel to the crankshaft installed in the
correct position.
Tighten the connecting rod big end nuts to the specified
torque (see Connecting Rod I ...
Troubleshooting Guide
NOTE
Refer to the Fuel System chapter for most
of DFI trouble shooting guide.
This is not an exhaustive list, giving every
possible cause for each problem listed. It
is meant simply as a rough guide to assist
the troubleshooting for some of the more
common difficulties.
Engine Doe ...
Air Switching Valve Removal
NOTICE
Never drop the air switching valve especially on a
hard surface. Such a shock to the air switching
valve can damaged it.
Remove the air cleaner housing (see Air Cleaner Housing
Removal in the Fuel System (DFI) chapter).
Disconnect the connector [A].
Disconnect the hoses [B] from ...