: Vacuum Switches



chwilliams3
03-18-13, 10:58 AM
Hey all:

Standing at the front of the car looking down at the supercharger, to the left there are 3 electrical switches clipped onto the top of the engine.

I had a lot of work done so it is possible that a mechanic missed this, but all 3 switches have vacuum ports. Only 2 have vaccum lines connected. The switch in the middle had nothing , not even a vacuum cap. I put on a vacuum cap, thinking that this could be a vacuum leak, and I did get better mileage.

Does anybody know what these switches are for and if all of them should be connected to vacuum lines??

Thanks for your responses all. L

Fierofiend
03-18-13, 11:06 AM
Only 2 should have vacuum lines. The 3rd is atmosphere pressure.

TimmyC
03-19-13, 12:34 PM
Only 2 should have vacuum lines. The 3rd is atmosphere pressure.

Correct. Cap is not necessary.

Ludacrisvp
03-19-13, 02:48 PM
Does it matter which two are connected?
(I dont have a V just going for clarification.)

chwilliams3
03-20-13, 03:35 AM
How do you calibrate the sleeve at the MAF. I had some mechanics at the body shop install it and I don't think they knew about the sleeve. Thanx

PGA2B
03-20-13, 09:51 AM
How do you calibrate the sleeve at the MAF. I had some mechanics at the body shop install it and I don't think they knew about the sleeve. Thanx

That depends on what you are talking about. If you are talking about a stock intake there is no true calibrating needed. Now if you are talking about a Spectre Intake the sleeve that is included takes care of that and it only goes in one way. The slit goes around the MAF sensor. Now you can move the orentation of the MAF sensor, and that is called "Clocking" the MAF sensor and it needs to be done on a dyno to check the power output but is only good for a few ponies. Finally if you are talking about one of Tim's intakes he will have to come in and speak to that. I do know his needs a tune to correct the MAF table. But I don't know if he does any clocking on the MAF.

CMNTMXR57
03-20-13, 06:39 PM
That middle one (#819) that is purposely meant to be open, as it is an outlet sensor of some sort. You have an inlet, and barometric pressure sensor also. Here is an exploded parts view I got from the parts department when I too inquired. You can also see the tubes that attach to #818 and #820 (parts #816 & #817). Personally, I bet he wrote them down wrong because it would make sense that the inlet and outlet sensors are hooked up via those tubes and the barometric pressure one would be "open-air".

http://i196.photobucket.com/albums/aa110/CMNTMXR57/STS-V/STS-VEngineexplodedview.jpg