I have a 1999 ford explorer with a 4.0 ohv. my problem is I replaced engine from a 1997 ford ranger engine and all the wire harness plugs matched up to the original wireing except the cam sensor plug. Mine has 2 wireplug and the new motor has a 3 wire plug. Ive been running without any plug connection at all to the cam sensor. any suggestions how I can hook this up?

 

They are two different kinds of sensors so there would be no way to just change the connector, the computer wouldn't understand the data from the "new" sensor.

2 wire is a Variable Reluctance sensor
3 wire is a Hall Effect sensor

You will need to swap out the 3 wire sensor for a 2 wire sensor.

With the Cam sensor unhooked the computer will run the engine in "limp mode" so instead of sequential firing of the injectors(one at a time) it will Batch fire the injectors, 3 injectors fire at the same time, this keeps the intake full of fuel/air to keep engine running, like a carb did.
So MPG will go down.
Spark timing can also be effected.