Page 24, Rx7Carl’s guide to (1983 RX-7) FB Rats Nest Removal
 

Carl says:

“There are two of these odd valves with metal hoses that run under your car. The skinny guy goes to the pre-cat, and the fat one goes to the main cat. Both need to be capped, and you can take our patented cut fold and crimp method. If you fold it - you will likely need to fold it twice to prevent leaks. Alternately, you could weld it shut or if you are lucky enough to be able to remove the bolts and simply disconnect it, you can even make blocking plates with the leftover aluminum. As you can tell by our chosen method - we wouldn’t bet on it.”

I can’t find these valves. Would they have been removed with the stock exhaust? Where do they originate? Anyone know exactly where they are located?


(This is a different question than my other thread about Sterling carbs and rats nest removal ;) .)

(I tried to include the picture but I couldn’t copy it.)

Thanks for any help,

DD

The "fat" one comes from the back of the intake. I have no idea about the other one. My '83 had new pipe from the manifold back when I bought it, and the port on the back of the intake was left uncapped, with the airpump belt removed.
If your car has aftermarket exhaust, they have likely removed these valves. They are for supplying the cats with fresh air, from the airpump.

Rogue_Wulff,

You were right on! I went back and re-re-looked (yes, re-re-looked 'cause I already looked once and didn't see it - senility i guess) at all the old exhaust and found at least one of those valves. Thanks for the reply. I really didn't know where to start.

I threw caution to the wind and cranked her up. She ran (in park) "like butta" (no hesitation, no stalling), but idles at 2K (I haven't adjusted anything yet.)

If you looked at my other thread about "rats nest removal and Sterling carb questions" I was/am confused about that one A/C solenoid. I just capped the top tube and gave it a shot. Seems good but it may not be correct. Please take a look at that post and see if you can give me any insight.

(Sterling carb, full RB exhaust.)

Thanks again,

DD

I saw that post. The throttle opener *should* be used when the A/C is still functional. If it idles without it, with the A/C running, then I suppose you have the idle raised a little higher than needed.

Yeah. Normal idle for stock engine is 750 rpm for manual. I think the throtle opener raises it 300 rpm. So if you're idleing at 2k rpm, no wonder you have not seen the need for it.