What Causes the Engine to Stall at Idle?

[LandonAnn]

Possible causes include clogged idle air jets, malfunctioning idle control system, weak spark in individual spark plugs, poor valve sealing, intake manifold leaks, incorrect ignition timing (either too advanced or too retarded), and improper idle speed adjustment. Engine Idle Instability: When experiencing unstable engine idle, first adjust the idle speed. If the issue persists after adjustment, inspect whether the idle jets and idle air jets are clogged. Checking for Air Leaks: If the jets are not clogged, stabilize the engine at a constant RPM and listen for air leaks at the intake manifold or the lower gasket area of the carburetor. Inspecting Spark Plug Performance: If idle instability is accompanied by reduced engine power, further examine spark plug conditions, valve sealing performance, and whether the ignition timing is correctly set.