What is on the back of the UIM, goes to the air pump on my 6 port. Wondering if its the cold start solenoid, if it can be removed, and if there is aftermarket block plates available commercially.

 

Actually it goes on the intake pipe..not air pump my mistake.

 

On the NA's it sounds like the cold start assist valve. Its just a valve that dumps antifreeze from a resevoir/pump from the engine bay during cold starts.

 

You mean the metal tube that runs around the back of the intake and goes over to the left side of the engine? It starts out leaving the intake duct as a rubbler hose and then attaches to the metal pipe that runs around the back of the intake?

Well, it feeds the Air Bypass Solenoid and supplys the BAC also. At least it does on a series four non turbo.