1998 Jeep Cherokee misses about half way up to normal temp

My Cherokee misses and back fires during warm up. It starts great and runs fine when cold. Then at about 140 degrees to maybe 180 it runs rough. And under power it back fires. Then once it's up to the normal 200 it runs great. I just finished replacing all the front parts (deer) - pass. Fender, nose piece and grills, bumper, both radiators, their mounts and had to straighten the inner headlight surround. I replaced the vacuum canister and the line to the cruise control servo. The heater works and so does the cruise. Am I missing some vacuum lines in that front passenger side?
Thanks