On my 94 D1 the lines are disconnected, Found a post here in regards to a D2.
Is it ok for these lines to be disconnected or should i hook them back up?
Thanks Guys

 

Unless they're plugged or connected, that's called a vacuum leak.

I think you're about to discover how much better your truck will run...

 

Usually the line on the passenger side attaches to the valve cover thru an oil separator. That sucks the oil fumes up to be burned off. A similar line is on the driver side, it goes to the throttle body and provides a source of filtered air to pass thru the engine and out the passenger side valve cover. If hoses are cracked, or what they plug into is sludged up, you'll have vacuum leaks, can build up internal open space pressure inside the engine to make oil leak out of seals, and can help sludge up the engine. Here's a pix of one of the areas they vent. Note that cruise control vac lines don't attach to motor, they have their own electric pump.

 

According to the manual these are coolant lines, hot water and cold return. They were not connected when i got the truck.

 

Oh those. They prevent the plenum from freezing up and the throttle from sticking. It's a safety feature.

 

Ahhhh, Well im in Florida not much chance of that.

 

That's the throttle body heater. You can get icing temps in Florida at certain times of year, certainly when you consider wind chill. It makes the throttle stick in position, like partially open. If it happens be prepared to shift to N and shut down the engine. A fix is about $25.

 

Ok thanks, but the manual doesn't show me where they connect to the radiator.

 

see attached, from shop manual. It is called the RAVE, and this is from page 357 of 873 in the workshop manual.