Starting motor running, but not cranking engine
Possible symptoms due to starting system trouble would be as follows:
Starting motor does not run (or runs slowly)
Starting motor runs but fails to crank engine
Abnormal noise is heard
Proper diagnosis must be made to determine exactly where the cause of each trouble lies.....in battery, wiring harness, (including starting motor switch), starting motor control relay (for K9K Engine), starting motor or engine.
Do not remove motor just because starting motor does not run. Check the following items and narrow down scope of possible causes.
1) Condition of trouble
2) Tightness of battery terminals (including ground cable connection on engine side) and starting motor terminals
3) Discharge of battery
4) Mounting of starting motor
For M13 Engine
Condition Possible Cause Action
Starting motor running, but not cranking engine
Worn pinion tip
Replace over-running clutch.
Poor sliding of over-running clutch
Over-running clutch slipping
Replace over-running clutch.
Worn teeth of ring gear
Replace flywheel (M/T) or drive plate (A/T).