I have a 97 lesaber a few months ago I needed a new thottle body not having a warm place to do it myself I had a garage do it.the guy at the garage got one athe one he t the junk yard to save me a few bucks,but on he got was form a different year and was missing a vacume port. Seeing that old throttle bodys two ports went to the same chamber he tied the two lines together and put them on the single port.since then I have'nt had much heat.not seeing how the two would be connected I thought maybe the termistsat was stuck open.the aintie feeze did'nt look good (used to be pink now brown and cap was gunked up) I recently flush the system put in a new thermistat and new radiator cap.put I still only get luke harm heat.temp gage only goes a little above 100.could the missing vac. Port be the problem?

Under normal conditions your cars Temp gauge should read between 180 - 210 degrees. If its reading low you need to verify what the actual temprature is. As far as a vacum line causing it that is not likely. The vacum could operate a valve but that would be unrelated unless you feel the valve is sticking and not allowing the water to pass through enough to heat your heater core. ( looks like tiny radiator) and fan blows across it to create heat for the interior.

I know what the norm. temp. should be and its not getting there and I know what a heater core is.I've change them in some of my past truck.I pretty much know the whole cooling system works,and did'nt think the two could be connected.but the heat worked fine then put the new throttle body on and the heat sucks.put in a new thermistat and radiator cap and heat still sucks I'm not leaking antiefreeze,oil is clean not leaking into the block.I'm baffled.

Did you verify the actual temp of the motor? Running that low can be a problem in itself because of the smog controls on the engine. What temp thermostat did you install?

No just going by the gage on the dash which I believe is pretty accurate because of the zero to luke warm heat I get.I had no where to flush or contain the old antiefreeze so I had a different garage do that along with the temostat.I normally do my own work if I can get it my brothers place in N.H.but here in mass in a 3 family condo the nieghbors would .

Since you didn't do the work is it possible that the thermostat was left out? That could explain why its being cold blooded. You need to focus on that first.

I believe they put it in but can't be 100% sure with out pulling the goose neck off.but it has been running cold for two months since the throttle body change.

The throttle body alone shouldn't have that much to do with the temp. Other then running rich or lean. But certainly not enough to make the engine run so low in temprature. Do you have an electric or a mechanical fan assembly for the engine?

Electric

Have you noticed if the fan is coming on right away when you start the engine? It shouldn't. Unless your running airconditioning or defroster.