What Does Negative Fuel Trim Mean - When your engine has a negative ltft, it runs lean or rich. Whether your engine runs rich or lean, it will lose power. Web fuel trims are temporary adjustments of the amount of fuel injected in the engine to keep the air/fuel ratio closest possible to 14.7:1, as 14.7 units of air mixed with 1 unit of fuel. Your engine needs the right amount of fuel and air. Small errors in this cylinder air/fuel mass estimations are expected but larger errors are an indication of trouble. One of the most common symptoms of a negative ltft is your engine losing power. In ideal conditions, the fuel trim will be always at 0%.
In ideal conditions, the fuel trim will be always at 0%. Small errors in this cylinder air/fuel mass estimations are expected but larger errors are an indication of trouble. Whether your engine runs rich or lean, it will lose power. One of the most common symptoms of a negative ltft is your engine losing power. When your engine has a negative ltft, it runs lean or rich. Your engine needs the right amount of fuel and air. Web fuel trims are temporary adjustments of the amount of fuel injected in the engine to keep the air/fuel ratio closest possible to 14.7:1, as 14.7 units of air mixed with 1 unit of fuel.