High idle intermittently

[Daryl333]

2017 GT, 6R80
Gen 3 Whipple.
After spirited drives when I put it in park and let it idle my rpms will climb to @2200 and sit at that point. If I shut off the heat/AC completely it will stop the high idle and go back to normal idle.
I get a heavy smell of gas at left quarter panel when this happens. Ive changed out the rear charcoal cannister and underhood purge valve.
Ive smoke tested a few times as well as Propane tested and have found no leaks. The car has been running fine for two years so its not in the tune.
I got someone to go over the tune in HPTuners and everything is functioning as commanded to. Have no codes showing in dash or on a scanner. What would be the connection between shutting of the Heater that stops my high revving idle? I would think it woukd be the other way around? But ive tested it many many times.
Anyone ever have this issue or point me in the right direction?
Thank you.

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[Daryl333]

If anyone else is having idle issues on their 2015-2017 Whipple Gen 3-4? Putting it on a scanner I found that my open blade voltage on my throttle body was in spec but closed blade was out of voltage range. Not far enough for a code tho. Codes start at .35 v mines at .36. Gonna tackle the magnet adjustment tomorrow. Hopefully this is the problem.

 

[Daryl333]

Well.
Got the voltages to all within spec. Still having hanging idle.
Back to the drawing board.

 

[engineermike]

The way ford controls idle is very interesting. It calculates how much torque the engine needs to make, such as pumping losses (pistons pulling against intake manifold vacuum), friction losses, torque converter, accessories, etc, adds some margin called “reserve”, then opens the throttle the required amount to make that torque. But that’s too much torque (due to the reserve) so spark timing below mbt and borderline is commanded to pull idle speed down. Remember, it has excess airflow due to the torque reserve.

You can imagine that so many parts of the engine calibration have to be right for this to work, including the pumping loss model, speed density model, torque model, tb model, and so on.

So timing controls idle speed but mbt and how timing affects torque must also be accurate in the calibration, and the timing must have enough range for adequate control. In other words, it can’t ride against mbt or min final timing and still control. If you have something like an air leak, timing might be running against the min final and can’t pull it down. Or who knows, maybe it’s commanding high idle for some other reasons such as a faulty high ect temp sensor.

Bottom line is it’s a guessing game unless you get a DTC or log some data to see why it’s high.

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