Changan Ouliwei was overhauled and turned off at idle speed. Just add some oil. What's going on here?

After the engine is started, it runs well from low speed to high speed, but it stops immediately after releasing the accelerator pedal, or it runs unsteadily first and then stops. This phenomenon can be judged as idle flameout fault. When the idle speed is turned off, the idle speed should be adjusted according to the actual situation. After adjustment, if the fault disappears, it means that the idler screw is improperly adjusted; If the fault can't disappear after adjustment, you can open the throttle and keep the engine running; Use cotton yarn or paper to check whether there is air leakage at the gasket of carburetor and intake pipe; If there is no air leakage, remove the idle metering hole for inspection, and blow out the idle oil circuit at the same time, and then reassemble the test; If the fault disappears, the idle metering hole and idle oil circuit are blocked. For carburetor with idle stop valve, check whether the circuit of cutting off electromagnetic coil is normal. If the idle fuel-saving metering hole is blocked due to abnormal coil circuit, the cut-off solenoid valve should be repaired.