No fuel to the engine-check aircraft valve on. Check fuel boost pump pressure.
Excessive air in fuel system-bleed fuel system. Check the reason for air entering thesystem.
No ignition-will give wet stacks. Caused by open circuit. Let engine drain and dry motorthe engine. Attempt start using air start igniters. Start accomplished -problem in aircraftelectrical system. No start-change igniters and/or ignition exciter. Caution: Allowignition exciter of snap type ignition to bleed off energy.
Fuel manifold adapters improperly installed-check proper position by proper ServiceBulletin.
Fuel pump failure-attach direct reading line in fuel pump to FCU line. Check for properpressure while cranking engine. Check FCU fuel filter.
Contaminated fuel system-check all filters. Clean fuel system as necessary.
FCU bypass valve stuck open. Check bypass valve for closing. Remove FCU cap fueloutlet and bypass fittings. Apply 5 PSI air pressure to bypass return port. If air leak isdetected at fuel inlet, replace the FCU (PT6A-6, -20, -27, -28, -34)
Start control defective-check primary fuel line for flow. If no flow, replace unit(PT6A-27, -28, -34)
Improper start technique-early removal of starter. Will also cause hotter than normalstarts.
Leaking or restricted P3 signal lines-check all lines for obstruction, cracks and security.Check P3 filter for contamination.
Pneumatic section of prop governor or fuel topping governor affecting Py signal blank Pyline. PT6A-41, blank also torque limiter.
Corrosion and/or ice in FCU bellows section-replace FCU.
Contaminated or defective FCU-check all fuel filters. Check FCU bypass valve.
Minimum fuel flow stop set too low-check minimum fuel flow. Remove Py line fromprop governor or fuel topping governor and leave open. Perform normal start. Check N1RPM per maintenance manual. Caution: Do not attempt this procedure on PT6A-41engines. Note: Usually PT6A-27 and -28 engines.
Hung start on PT6A-27, -28 and -34-check SFC dump port for fuel. If dumping, replaceunit.
Prop slow to attain idle RPM-prop shaft transfer sleeve binding. Check covers on transfertube bosses. Binding accessories, remove one at a time.