Car only start when the engine is cool if driving once the engine heats it switch of after 20 minutes

The fan is working at high speed before the engine heat. I have change the thermostate and heat sencesor

Delay to start and over heating

Turnover but wont start has comprision

It turns over but wont start

Over heated so i replaced head gaskets (diy ) first time ever put all back together now it cranks but wont starti can hear fuiel pump wrkining see a spark tryed starter flued but just wont start dont…