quick! help! vacuum modulator on trans!

[ZachS]

hey guys!

There is a T-fitting for vacuum hoses coming off of my vacuum modulator for my trans...

The one side of the T is supposed to be OPEN right?!

The shop that did my trans plugged it.  

I'm almost positive it is supposed to be open... can anyone verify!?

TIA
Zach

[GPChief]

Open it!!!!!  It probably makes "clunking noises, and shifts like poop"  It needs to be open because our cars need to be able to bleed off excess "vacuume / boost" since they are turbo automatics.

[idbeast]

You need to unplug it, the bleed is for when the car does boost- it is positive pressure- not vacuum. The vacuum modulator only works under vacuum and it doesn't know how to act with positive pressure (will take your tranny out because of improper internal pressures). :shock:

[skalor]

My car had the t fitting at the modulator and it was losing too much vacuum with the open end and it was shifting really hard into gear.  I replaced it with just a checkvalve so that it gets just vacuum and it shifts into and out of gear nice and it shifts really good too.  I think the fact that my car doesn't have the original tranny has something to do with it though.

[1trucavalier]

i looked at mine yesterday and it had a big screw in it :cry: , I knew something wasn't right.  I hope it didn't damage my tranny cuz its shifing funny now :evil: !!!!!!!

[1trucavalier]

I replaced my vaccume modulator this weekend and left the vent hose open this time.  It shifts fine but seems kind of slushy sometimes.  I have noticed that the after the shift to 2nd the trans shifts right back making the rpm's go back up (sometimes).  I am going to check for correct vaccume first.  I was thinking that the torque convertor is locking up an not releasing right.   Do we have a TCC switch? if so where is it? and how come its not listed or shown at all in the repair manual.  I did notice though that the car shifts better with the plug just above the vaccume modulator unplugged.  What is this plug and will it cause any damage if its unplugged.  I did plug it back up because I don't want to take any chances on messing up something until it is clarified what it does.  Any info is appreciated.  :?:

[Chris A]

Its the plug for the shift switches, and for the TCC lockup solenoid. Maybe the TCC is locking too soon causing it to feel weird. Its an ECm commanded function so I'm not too sure about that one. Its possible the solenoid is getting stuck. I think in the dengerized position it keeps the TC unlocked, and in the energized position its locked. It may be getting stuck somehow?

Chris

[1trucavalier]

I  bought the switch but don't have a clue where it goes.  Where is the TCC switch located?

[turby]

If I'm thinking of the right thing it should be directly under the turbo on the front of the tranny. (facing the front of the car)

[1trucavalier]

I'll take a look sunday in my f-n-laws garage it was 19 deg here last night and aint no way I am working on that car in that type of weather  :( !  I got a new crank sensor, TCC switch, 02 sensor (already on), 34mm swaybar, STB front and rear, alarm, and 24lb inj (on there way) and its tooooo cold to put them on :evil:

[turby]

Where did you get 24 lb. injectors?
part #?
price$?

[Chris A]

LOL on the TCC switch. You have to remove the crossover, support the tranny and remove the bracket that holds the tranny up. Then you have to remove the driver side axle and the side cover for the pan. You may even have to drop that side of the subframe down.

Chris

[turby]

OK, I guess I was way off on that one.
Sorry,  :oops:  I was thinking of the one on my Buick Somerset.

[Chris A]

OK, I guess I was way off on that one.
Sorry,  :oops:  I was thinking of the one on my Buick Somerset.

Oooops. Guess I should have quoted the message I was LOLing at. I was just thinking about all that had to be done to get to that solenoid and laughing at the original question! :)

Chris