What if Hafei racehorse can't catch fire at idle speed?

It may be caused by carbon deposition in the intake pipe. Due to the unsynchronized operation of the pistons in the whole engine, when the engine is turned off, the intake valves of some cylinders cannot be completely closed, and some unburned fuel is continuously evaporated and oxidized, which will produce some soft black carbon deposits in the intake pipe, especially behind the throttle. On the one hand, these carbon deposits will make the pipe wall of the intake pipe rough, and the intake will produce eddy currents in these rough places, which will affect the intake effect and the quality of the mixture. On the other hand, these carbon deposits will also block the idle channel, making the idle control device stuck or beyond its adjustment range, resulting in difficulties in starting, low idle speed, idle jitter, failure of various auxiliary devices to speed up, oil collection and flameout, excessive exhaust gas and increased fuel consumption. I suggest you check according to the problem of carbon deposition.