Short-term fuel trims are a parameter used by the engine control module (ECM) of a car to adjust the amount of fuel delivered to the engine. They represent the deviation from the base or target fuel delivery rate, which is set by the manufacturer. The short-term fuel trims are typically displayed as a percentage value, which indicates the percentage increase or decrease from the base fuel delivery rate.
With this information, I can determine if there is too much, or too little fuel being injected into the engine. If the trims exceed the parameter at either end of the scale, it can cause a misfire. Additionally, I can use this information to determine if there are issues such as exhaust leaks, a faulty fuel pressure regulator, an engine vacuum leak, and many other things.
Let me know what you find.
Monday, April 3rd, 2023 AT 7:36 PM