What parameter limits control authority/ servo throw for FBWA and AUTOTUNE?

I have severely limited authority in FBWA and AUTOTUNE.
FLying a fx-79, with new style elevon mixing.

I increased MIXING_GAIN param to 0.8 to achieve (more than sufficient) satisfactory control throws.
But in Autotune and FBWA the throws are very limited. the control surfaces barely move beyond neutral for pitch up.
This results in the plane not having enough control authority and diving to compensate with speed( i think).
I deliberately set it up a bit nose-heavy, but it flies fine in manual mode.
But that is to be expected when the control surface deflections in the automatic/augmented/stabilized modes is only a fraction of what they are in MANUAL and and pitch up deflection is only a few milimeters above neutral.

What is the parameter that limits servo throw in automatic/augmented/stabilized flight modes?

#SOLVED: Pitch P and Roll P, default values were too low. Increase in 0.2 increments and GROUND CHECK throws.

use mixing - gain with at least 1 for big plane and less then one for small plane (wing wing FX84) …plenty of throw… don’t even bother with auto tune on fx-61/79 …they fly alone …get cg right and fly away… best planes ever

I believe this is what you’re looking for. - http://ardupilot.org/plane/docs/parameters.html#ptch2srv-imax-integrator-limit. A similar paramter exist s for roll, RLL2SRV_IMAX.
From the docs -

This limits the number of degrees of aileron in centi-degrees over which the integrator will operate. At the default setting of 3000 centi-degrees, the integrator will be limited to ± 30 degrees of servo travel. The maximum servo deflection is ± 45 centi-degrees, so the default value represents a 2/3rd of the total control throw which is adequate unless the aircraft is severely out of trim.