Trane heat pump air not warm enough

I have a 7 year old Trane xl16i heat pump 3 ton with electric strips backup. Auxillary strips have been disconnected to try and find my problem.



My problem is that in outdoor temps of 45 or so my air supply at the handler never gets above 75. Return air is 63.



I hooked up gauges and here are the readings.

outdoor temp is 35

Suction pressure is 110psi

liquid pressure is 280psi.

both are within the spec curve called out in the manual for that temp.



the suction line temp at the outside condensor as it leaves is around 140deg.



suction line temp entering air handler is about 115deg.



Liquid line temp entering air handler is 72deg.



Any thoughts? I lowered the blower speed to 350cfm per ton, was 400.



clean indoor and outdoor coil as well as air filter. I know on service calls in the past my unit would put out 90deg plus easily



thoughts?



Thanks

Trane heat pump air not warm enough