Recently switched engines in my 1990 superduty, took out a automatic transmission engine , and installed a standard shift transmission engine , noticed that auto tranny engine has a switch on side of injector pump, where as the standard transmission engine doesnt, what does it do, and what are the consequences of not using it? It has a very long slots in bracket where it bolts to pump housing, how would I know if it's even adjusted right after installing it?

 

probably reads the throttle to tell the trans when to shift

 

Could also be the Cruize Control Vaccum controller ?

 

FICM for the E4OD, it serves the purpose of a TPS.
It is required for proper opperation of the transmission.