[DesertMK4]

We are all just guessing here...but with a Holley you have a fast idle adjustment that could be off. Fast idle (when choke is on) should be around 1400-1600RPM. You might try cleaning and then resetting idle screws. See Holley TV. Some Ford engines need the spark plug wires separated (mostly between the 7 and 8 plugs). Reading the plugs should at least tell which plug isn't firing. Good luck tracking down a temperature variable problem.