I have been searching and searching for a solution to my idle problem. And after adjusting and fine tuning a million things, I am so close to getting it right. Now the one thing I have not been able to adjust is the BAC because I don't know where the screw is that everybody is talking about. Some one please show me a picture or a very in depth write up. i have an 87 n\a with a S5 intake. But the BAC is still from an S4. On the BAC there is a deep hole but there is no screw. But enough babbling, some one please help.

 

Early RX did not have a screw in the bac. Just that blank hole. Stop looking. It ain't there.

 

DAMN

Thanks
Ryan

 

I think it's the turbo's that have the idle bleed adjust on the BAC.
The NA's adjust on top of the dynamic chamber..

 

Ever try adjusting the variable resistor?

 

I have adjusted damn near every thing. When I first got the car back together and started it up, the rpms went sky high ( 5000 ). I can't remember how i fixed that. Then I went through the whole hunting idle bit and somewhere between adjusting the idle speed, the tps, and the primary throttlew plate gap. I got rid of the hunting. Now I can't get the idle down anymore. It is stuck at 1000. My list of things to try is as follows:

Loosen jam nut on bottom of TB
Tight fast idle screw a little ( roller might not be releasing from cam)

I have removed the air bypass solenoid, that had the idle at about 2500

And blocked off the water thermo switch where the vacuum escapes after a certain temp(70 degrees F)

So there it is, what do you guys think.
Ryan

 

I'll buy into the fast idle cam and screw idea. It's hard to see and work on with the throttle body on the engine. You might try taking it off and pouring boiling water over/into the thermowax area and watch to see if the cam falls off the roll pin. You also might take the thermowax apart to make sure the water passage isn't blocked. That would make the operation of the thermowax slow to react.

In short, yes, I think its keeping your throttle plates open just a tash.

At sometime I'd try to get a good bac on the car. They help. Maybe soaking the old one in some lubricant and cleaning it would help. Sounds stuck. Might check the resistance of is coil per the fsm also.

 

I have tested the BAC it works. The water passage is clear. But I did mess with fast idle stuff so, a while ago i had to put it all back it still may need some tweaking.

Ryan

 

do you have slack in your throttle cable?

 

Yes, I all ready had that problem. That was actually how I fixed The very high rpms (5000). I couldn't remember in an earlier post.


Just a thought, I also took out my six port and blocked off the VDI. Could that be something that might be keeping the rpms a little high?

Thanks
Ryan

 

There is one other thing. When I rev it it will stall. And then I can't start it again because it is flooded. I don't know.

I adjusted the plate gap again but have not gotten a chance to test it because of the problem stated above.

Ryan