Engine hard to start or will not start - smoke from exhaust

Cause   Correction
Contaminated
fuel
Verify
by operating the engine with clean fuel from a temporary tank. Drain
and flush fuel supply tanks.
   
Worn
or malfunctioning injection pump
Visually
check fuel delivery with an externally connected injector to one of
the pump outlets. Replace the pump if fuel is not being delivered.
   
Injection
pump out of time
Check/time
the pump.
   
Valves
incorrectly adjusted
Adjust
valves.
   
One
or more injectors worn or malfunctioning
Check/replace
injectors.
   
Engine
compression low
Perform
a compression check to identity the problem.