my engine missfire when it reaches normal temperature cant drive it on 2001 Ford Explorer

i have changed many thngs in the engine but cant see the fault yet any idea wat causes this problem as soon as the engine reaches half the temperaure on the dash board the engine missfire i have to switch off the egine start again specially if am going high hill

Asked by for the 2001 Ford Explorer
do u have any eng codes or live data info to share