Water in Fuel System

If water enters the fuel system, it can alter the fuel/air ratio and reduce engine power and/or fuel economy, potentially stalling the engine. If water enters the combustion chamber in small amounts, it may be evaporated from the engine heat. If the amount of water is significant, the water can soak the spark plugs and cause an electrical short to the block or making for a weak spark. Enough water can cool the engine to a point where the water cannot boil away. This could cause extended cranking, stalling, or stumbling/very low engine RPM (around 300-500 RPM).