slitherz90gxl

I unhooked my BAC valve and nothing happened.... I drove it down the road for a bit and it drove like it usually does the idle was the same; etc.
That means that it is bad right ? and I need to buy a "new" one ?

HAILERS

There will be a change in the idle speed when you remove the BAC plug ONLY if the idle is under........about 650 to 700 rpm in general. IF the idle is over 800 you won't notice a thing when you pull the BAC plug off. Normal as can be.

BAC has no effect on driving at speed, only idle. Its a idle control valve.

slitherz90gxl

I guess I could have went into more detail, but football is on. I drove around because I wanted to make sure it was still fully warmed up.
My car has been idling (when hot) between 500 and -300; it drops below zero and then bounces back up.
Most of the time it just dies though.
I checked for vaccuum leaks and only found one and I fixed it already.
I tried to check the tps; I think I did it right and it checked out okay.
I didn't touch the idle screw it because the bouncing idle wouldn't be caused by that I don't think and it is about half down/up.
So I figure either the BAC valve is messed up, I mischecked the tps and it is bad, or my idle problems are simply because my engine is slowly killing itself.
.......
If you have any ideas of what would cause this other than what I listed that would be nice because I've searched the forums and the above is all I can think of.

HAILERS

BAC valve disconnected should have made a difference then.

Undo the two nuts that hold the BAC on and pull it aside a bit so you can see the guts of it. While looking, have someone turn the key to START. When the key is HELD to start, the BAC should open full (about a 1/4").

If it does not do that, I'd say the transistor in the ECU for the BAC is toast. You might take the car out of gear when he puts it to start. Might not. Depends on you .

I don't think you have to remove the water hose on the BAC to do the above.

Never shove punch or screw with the guts of the BAC.

I'm not familiar with series five BAC. Does it have a air screw in the side of it? Sort of recessed in a bung? Might not. I know not.

arghx

iTrader: (3)

Did you follow the idle set procedure in the service manual first? That involves jumpered the initial set and turning the air adjusting screw. I know you think that won't do anything but you really should try it first.

slitherz90gxl

I can't get to the two nuts that hold in place.
I'm not for sure on that screw either, I'll check tmrw whenever since it is dark right now.

slitherz90gxl

I played with it a little bit; maybe this will help find the problem.
I followed the service manual adjusting procedures and even experimented on my own a little bit.
I adjusted the screw to where it would idle at 750ish when warm but after I drove it a few minutes the idle returned to crap and I noticed that it didn't want to stop moving; imagine how scared I was whenever I have no brakes and I let off the gas only to see the speedo stay steady.
Anyways; when it was cold it was idling at 1,700+.
I think some of it might have to do with my fouled plugs, but I won't get my new ones until next week.

arghx

iTrader: (3)

So it was surging? That could be a TPS problem.

That's your fast idle system holding the throttle plates open. The warm coolant will then expand the thermowax rod in order to rotate the throttle plates back to a more closed position.

slitherz90gxl

By it didn't want to stop I meant the car was pulling itself if I let off the break.
The idle is surging though... a lot.
I thought tps, but I'm going to see if a friend will help me adjust it because I think I did the procedure wrong.