Starts up ok when cold and runs fine, when it gets hot it starts to miss and then if turned off won't restart until it's cooled down probably an hour later. So far tried a new fuel pump and carborettor to no avail It's an old ford consul Any ideas?

My Daily work truck (Mazda B2200 diesel) is giving me some agro, i keep getting an annoying coolant light and buzzer coming on,the heater is ice cold at best, the temp gauge hardly moves off the blue......the bottom radiator pipe is stone cold but the top one is boiling hot!.....i reckon it...