We have a central ac unit that runs constantly not keeping house cool. We just replaced evaporator coil and heating unit. Outside service done on condensing unit. Thermostat set at 77, does OK until mid morning then it doesn't shut off and house temp rises to 80-81and doesn't cool back down until 11 at night. Any ideas?

Could be an HVAC issue, could be the ambient temperature overloads the unit. Could be lack of shade or insulation. The fact that it cools down the house at night, indicates reasons other than just the unit itself. Where are you located?

New orleans

At 1:40 EDT, the temp at NO airport was 92 with a heat index at 99. You can expect an average drop of 15-20 degrees with AC. However, it depends on a lot of other factors. Where is your AC located ? If in a poorly vented and insulated attic, you will probably never get 77, not with an index of 99. If you don't have good attic insulation, good insulated ducting, good wall insulation, Low E windows etc, what you are getting is about expected. Have you ever had a Manual J done? AC installer should have done one. Is the new coil the same Freon rating R-22 or 401A?