挖掘机自动化程度高，设计有自动油门，当关上钥匙开关后发动机能自动熄火。如果该电路发生故障，可引起关上钥匙开关后发动机不能自动熄火,又导致发动机不能再次启动的故障。下面从电路原理、故障诊断和检修实例等方面进行介绍，有利于准确、快速地排除该类故障。1　电路原理t Excavator high degree of automation, the design has automatic throttle, when the key switch off the engine can automatically turn off. If this circuit fails, it can cause the engine to fail to turn off automatically after the key switch is turned off, causing the engine to fail to start up again. The following from the circuit theory, fault diagnosis and maintenance examples and other aspects are introduced, is conducive to accurate and rapid elimination of such failures. 1 circuit principle t