The 2013 Ford C-Max Energi has the most overall complaints, & we also rate 2013 as the worst model year ranked on several factors such as repair cost & average mileage when problems occur. The Ford C-Max Stalling Problem Causes. Here are some of the issues that cause the C-Max to stall out. Remember, a vehicle needs air, fuel, and spark to run. It needs them in the right quantities and intervals, or it won’t run right. Fuel. Fuel issues are one of the most common reasons that a vehicle would stall out, that includes your Ford C-Max. bYznz8U.