Some TB vac. questions Options

[95celgt]

So on my 3s, there are 2 ports that come out of the throttle body, are they both supposed to be under vac.?
The reason I ask is because my car has crappy vac now at idle, 15 when the fuel pump sounds like its pumping at a fast pace, then the fuel pump clicks into a slower pace and drops to 10vac. and it basically idles like crap and trembles and stutters...

On mine only one side does anything, im using that port for my BOV and my Boost/Vac guage, the other one is connected to the charcoal canister, is that where its supposed to go?
Since the port connected to the canister is dead, i want to know if the cansiter is supposed to be under vac.

I tried putting that red hose that goes to the canister at the T in place of the BOV to see what it does, the idle stabilizes nicely but at a higher rpm, and the guage reads that it runs at "0" so at atmospheric pressure.

I ask for a few words of wisdom, thanks

[95celgt]

the welded flange?

So should the canister be under vac?

How come it idles nice but makes the engine run at atmosphere?

[phattyduck]

the welded flange?

So should the canister be under vac?

How come it idles nice but makes the engine run at atmosphere?

Don't use any of the ports on the throttle body for anything but the evap and EGR system. They are ported right at the throttle plate (sometimes a bit before, sometimes a bit after) and don't give reliable readings about what is happening inside the intake manifold.

You should use the vacuum hose that goes to the stock BOV (if you have one) or any other line that comes directly off the intake manifold. I would also avoid using the line that goes to the MAP sensor, but with a gen2 motor (are you you using a gen2 or gen3 motor?) it is less critical.

-Charlie