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Thread: Target AFR no change.

  1. #1

    Post Target AFR no change.

    Hello. Problem, making changes in the Target A/F Ratio table makes no change in engine idle. Engine fully warmed up, out of all modifiers, in Closed Loop, Base Fuel Learn turned on, 100% Gain, Learn Above RPM turned off, Learn Above TPS turned off, Online active. It has been running for a while, but I wanted to fine tune my idle AFR. I highlight the area and make the change, no change in idle. I change screen and get the message, "Do you want to save the change in the Base Fuel Map?" I'll say yes and go back to the TAFR table. I can see the changes I made, but can not notice any change in engine idle. I have gone from 14.7 to 13.5 and notice no change. My CL Compensation stays around "0". I get the all green lights when I startup and sync. Any idea would be appreciated. Thanks.

  2. #2


    You're trying to find the engine's "idle AFR happy spot". I don't do it by changing the Target A/F Ratio table with Closed Loop & Learn on. There are other CL parameters that will slow down that process or limit its range. It's easier & faster to just turn CL OFF and manually adjust the numbers around the idle football while watching the IAC Position & vacuum. Go lean until the engine doesn't like it (IAC will rise), and then go rich and settle on the best place in the middle with the lowest IAC Position and best idle. Note the Actual AFR where you ended up, then transfer that to the idle area in the Target A/F Ratio table, and then turn Closed Loop back on.

  3. #3


    OK, sounds good. I'll try it and re-post. Thanks.

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