Troubleshooting of engine.

 Starting problems :

1. Engine fails to turn on air after operating air starting lever.
Possible causes :
a. Pressure in Air Bottles too low.
b. Isolating valve on Air Bottles closed.
c. Isolating valve on Air Distributor closed.
d. Control valve for Air Distributor sticking.
e. Low control air pressure.
f. Main Starting air valve jammed
g. Turning gear interlock.
h. Reversing not taken place.
i. Bursting diaphragm on Air starting line damaged.
j. Valve for operating auto Air start valve not operating.
k. Valve for operating air to Distributor not operating.

Engine turns on air but does not fire.
Possible causes:
a. Regulating shaft held back by stop cylinder.
b. Shut-down piston of fuel pumps.
c. Valve supplying Air to puncture valve not cut-off.
d. Boost air is not supplied to Governor.
e. Governor air booster does not supply adequate oil pressure.
f. Pre-set control air signal to Governor too low.
g. Fuel pump index too low.
h. Fuel filter blocked.
i. Auxiliary blower not functioning.

Exhaust temperatures high :
1. All units.
Possible causes :
a. Scavenge air temperature is high, due to insufficient air cooler or scavenge fire.
b. Fouled scavenge air and exhaust passages.
c. Bad combustion due to fuel characteristics, inadequate treatment of fuel.
d. Wrong timing
2. Any particular unit.
Possible causes :
a. Defective fuel injector.
b. Leaking exhaust valve.
c. Blow-past.
d. Slipped or wrongly adjusted fuel cam.
e. Defective pyrometer

Engine RPM falling :
Possible causes
a. Air lock due to inadequate venting/ gassing of fuel.
b. Booster pump pressure low.
c. Defective fuel pumps / fuel injectors.
d. Water in the fuel.
e. Insufficient air due to Turbocharger problem.
f. Scavenge fire.
g. Fouling of the hull.
h. Combustion characteristics of the fuel.
i. Problem in the governor.

Smoky exhaust :
Possible causes :
a. Turbocharger rpm low.
b. Insufficient air due to choked inlet filters / irregular running of turbocharger.
c. Defective Fuel injectors.
d. Scavenge fire.
e. Incorrect fuel Timing.
f. Afterburning.
g. Incorrect viscosity of fuel before injectors.
Hot spots in Crankcase :
Possible causes :
a. Inadequate purification of the crankcase oil.
b. Bearing overheating.
c. Touching of rubbing / sliding surfaces.
d. Scavenge fire.

Reduced compression pressure :
Possible causes :
a. Defective or worn-out piston rings.
b. Burnt piston crown.
c. Worn or oval cylinder liner.
d. Damaged or burnt exhaust valve.
e. Incorrect exhaust valve timing.
f. Insufficient scavenging.
g. Low spring air pressure.

Loss of power :
Possible causes :
a. Fuel rack settings incorrect.
b. Insufficient air.
c. Faulty injectors.
d. Faulty fuel pumps.
e. Loss of compression.
f. Governor malfunctioning.
g. Fouling of hull.
h. Change in fuel timings.
i. Change in VIT rack / settings.

Overspeed :
Possible causes:
a. Fuel rack stuck.
b. Fault in Governor.
c. Racing of Propeller.
Knocking :
Possible causes :
a. Injection timing incorrect.
b. Faulty injector.
c. Worn out bearings.
d. Excessive play between Piston and liner.
e. Fuel characteristics.