Open Loop EQ Ratio when Speed Density tuning

I'm new to tuning and have been trying to figure out why my Gen 3 keeps commanding 13.8 AFR at idle when at operating temp. Should I have the Open Loop EQ Ratio set to 1.00 at operating temperatures to keep the Commanded AFR from being so rich?

I'm using an AEM Wideband sensor to tune.

I hope I'm attaching a screenshot of my Open Loop EQ Ratio table

Lots of the early calibrations are like that, it's normal because the engine would already be warm enough to enter closed loop operation and no longer would be using the open loop EQ ratio. Why exactly it was changed later on to be at 1.00 above 130-140 degrees is not something I can say why but it is what it is.

So for your speed density tuning in open loop you will need to make it 1.00 at operating temps, so above 140-150 degrees is good.

Thanks!!
Would the Commanded AFR being lower like that skew the numbers in the VCM Scanner when trying to tune the VE table?

Attachment 94633

Yes, they would.

Good deal. Thanks for the responses.

Another dumb question. So if the Open Loop EQ Ratio table hadn't lowered the commanded AFR, the table in the VCM Scanner would have shown an even greater rich condition "OR" Is it impossible to know because the computer would not have added as much fuel if the Commanded AFR was Stoich?

Trying to get my head wrapped around this tuning thing but I'm not sure that question even makes sense!lol

Let me back up a second. When you are tuning in open loop, the wideband error you create is going to tell you how far off you are from the commanded AFR. So to change my previous answer, it wouldn't exactly skew the numbers because you are still taking the error from the commanded.

The problem comes if you switched back to closed loop. Closed loop is going to target the stoich you have set in the tune, so that is likely 14.63 or 14.68 for regular fuel. If you did all your wideband tuning with a open loop EQ ratio/AFR of ~13.8, the fuel trims would show you that something is wrong. They would be trying to pull fuel to get back to closed loop stoich and not the open loop target value.

So this is why we make the open loop EQ ratio 1.00 so it targets the stoich value when at operating temp.

That's understandable. Thank you for the explanation!!