Fuel trims and wandering idle

[Stl-986]

As Blue pointed out, you are trying to compare 2 different things. Might be looking at an issue that isn't really an issue at all.

[blue62]

Originally Posted by Stl-986

As Blue pointed out, you are trying to compare 2 different things. Might be looking at an issue that isn't really an issue at all.

Correct.
If the car runs fine has good power decent fuel milage, and no codes then the car is performing within design parameters.

To look at a screen shot of something like Fuel trim data and think oh this is great because it comes from so and so is pointless. Without surrounds data like coolant temp. RPM, Engine load, Throttle position sensor data, O2 sensor data. That screen shot is meaningless.

In most conditions to look at a single frame of data of any type without surrounding data is a waste of time.

When looking at fuel trims as described by something like Durametric they are broken down into RPM ranges. Idle, cruise, and upper RPM. IIRC fuel trim or adaptation is figured or calculated differently for each range. So you can't compare fuel trims from idle to fuel trims from cruise or mid range and have it make any sense.

Also if your at one RPM say Idle how could you have fuel trim at another RPM at the same time.