The test data of an engine outfield starting failure were analyzed.Also

the temperature field during startup was measured and the low oil pressure spray test of fuel jet nozzle was conducted.Finally the fuel jet nozzle carbon deposits were validated to decrease the fuel nozzle spray cone angle and deteriorate the quality of fuel spray

affecting the reliability of the cross ignition directly in engine starting and yielding a great impact on engine starting performance.The parts test results show that the insert depth of swirler has no effect on swirler outlet spray.The utilization results of engine simulation outfiled show that when the engine is operated for a long time under low state of power not greater than 30%

the centrifugal-type fuel jet nozzle is prone to carbon deposits.