I think my bac valve is ****. I cant find one a t a junk yard and the mazda dealership wants 350 for one. Is there any good way to test it and more importantly get it working till i find one. Is it safe to run with a bad valve?

 

if you have an n/a, i have one lying around somewhere...
and yes it's ok to run with a bad bac (some people have theirs taken off)...now no to checking it...search, there was a post on here not to long ago...

 

you can just run without it? If so dont you need a block off plate or something? If you find yours let me know

 

well, you can leave it on there, just unplug the electrical connector if you don't have a block of plate...and i know where mine is, but i'm a little reluctant to sell it to you unless yours is really dead...reason being, they don't normally go bad (so i'm told) and i don't want to take your money if yours is still good...but here's a how to "clean" link...http://www.1300cc.com/howto/how2/bac.htm
more often then not, the bac valve stops working because it's too gunk'd up...
after you clean it, supply a 12v to it's electrical terminals and see if they click, if they do, it's working...you could also test this before cleaning...
by the way, what makes you think your bac valve is bad anyway?

 

will the cac valve only mess up if the idle screw is on it??

 

um.. i can get you a BAC for very little money

 

no, it will only mess up if you've fried the electrical components or the valve is stuck shut or open and you can't unstuck it...

it could also be your ecu, but again i ask you, what makes you think your bac valve is messed up?

 

i idle goes to hell. I disconnected it and turnned all my accessories off. MY idle would just flux about 300 rom. I adjusteed the throttle sensor and got it flattened out. I drove around a little more and things seemed ok. I took apart my bac valve. I cleaned it and started my car. I cranked all ac's and no drop in idle. I think my cleaning work. Unfortunately my BRAND NEW TIRE THAT WAS PUT ON TODAY

 

is flat!