2002 ford 7.3 diesel starts just fine 30 min latter dies won't start again for maybe 30 min starts up and runs tell it gets warm again and dies I changed cam shaft sensor and tried to read the codes reader gets no power to it

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On diesel engines that will not restart, after they are warmed up, it's often a sign of a tired fuel pump. As they heat soak, inside pump head clearances increase and it will no longer develop sufficient fuel pressure at cranking speed. While it's running, fuel helps cool the pump by carrying the heat away.