1986 Toyota pickup don`t start after one hour rest during winter.

My 1986 Toyota pickup don`t start after one hour rest during winter. (In Quebec, it’s very cold   – 20 F.) No problem when warm, no problem when cold. When the problem occur, I got fire on plugs, but the fuel does’nt come. After it cool down, the engine start easely. I think that a sensor is in trouble. If it’s right, which once. If not, where should I look.