spit and backfire whenat or near 32'farenheit

This last spell of cold weather my 1989 4x4 pickup 4cyl was having a severe
problem when cold. Every morning when it was at or near 32'f, my truck
would not get out of its own way. It would buck and fart really bad. But
if I let it warm up alittle it would be better, but not perfect until full
hot. The truck has 212,000 miles on it, but still runs strong now. It has
always had a slight cold hold back, but never as bad as when it was really
cold this couple of months. If anybody has any suggestions please let me
know what it could possibly be. It already has a new Toyota fuel pump and
Injectors. Anything would be helpful Thanks Brendon