bac Valve
 

I have a 87 TII.
my car has a really rough idle problem,
I try to adjust the idle screw on the BAC valve, but it doesn't make any differents,
and I unplugged the electric connector on the BAC valve , but it doesn't make any different too. so I took the BAC out and clean it , and it still doesn't work. is that mean I have a bad BAC? my problem is can I use 89-91 BAC valve on my engine?
will exhaust leak cause bad idle?

PS: TPS is good , and engine has good compression.

Had the same problem. I was getting funky idle problems and adjusting the BAC screw didn't seem to do anything. I bought a used BAC off a friend and replaced it. It seemed to do the trick. I have an 87 TII also.

see if the valve is good first. hook one side up the power and the other to ground, see if it clicks. if it does not then you need a new one

mike