With the increase in recent years of the number of fuel injectors on our engines, has been a number of complaints about a mysterious occasional engine "miss" in flight. We have been able to verify that the majority of these complaints on fuel injected powerplants are from contamination in the fuel - principally water. We have been telling operators for many years that fuel injectors and their systems are more vulnerable to contamination than are carburetors. Since water and other contaminants collect on the bottom of the airplane fuel tank, it also makes good sense not to make a practice of running a fuel tank dry.
Careful draining of fuel sumps for water will help alleviate the "miss" problem. A sufficient amount of fuel must be drained to ensure getting the water. Experience indicates that draining should be accomplished before refueling because fuel servicing mixes the water and fuel, and the water may not have settled to the bottom of the tank until the airplane is airborne. Learn to identify suspended water droplets in the fuel which causes the fuel to have a cloudy appearance; or the clear separation of water from the colored fuel after the water has settled to the bottom of the fuel tank.