Where is the oil pressure sending unit located on a 1986 ford 150 econoline van with 351 5.8 liter?

The oil pressure sending unit on a 1986 Ford Econoline 150 with a 5.8L (351) engine is typically located on the driver's side (left) of the engine block, near the front. It's a relatively small unit with one or two wires connected to it. However, the exact location can vary slightly depending on the specific engine configuration.

To be sure, you'll need to consult a repair manual specific to your year and engine. A Haynes or Chilton manual would be helpful. You can also try searching online for pictures of a 1986 Ford 351 engine bay – visually comparing your engine to the pictures will help you locate it. Be careful when searching as some images might be of different years or engine types.