Explain how unburned fuel can appear in the the exhaust duri

Explain how unburned fuel can appear in the the exhaust during the intake and exhaust strokes in an engine.

Solution

A backfire is an explosion produced by a running i c engine which occurs at the air intake or exhaust system rather than inside the combustion chamber. If it does occur in the exhaust, is called an after-fire. and backfire is when unburned fuel moves back into the intake, and combusts, whereas an after-fire combusts unburned fuel in the exhaust side of the combustion cycle.

An emission system malfunction, like an air injection system diverter valve problem, an exhaust leak, or when the catalytic converter is been removed, then backfire can occur.Rich running engnes also cause an incomplete burn which causes the fumes to explode in the exhaust system along with an audible pop or bang sound. This is a result of working equipment, and is unlikely to cause damage.

A fuel-injected engine may backfire if an intake leak is present (causing the engine to run lean), or a fuel injection component such as an air-flow sensor is defective.

Common causes of backfires are: