This is going to start out a little vague but hopefully my question will become more clear as we go.
So I recently swapped the motor out of my 85 GLS that had a blown apex seal. While putting it back together there was a little plunger that had a small rectangular rod coming out. This rod has two holes in it and one of them goes over a pin below the carburetor. This pin can move forward and back and changes the position of the plunger from what I assume is "open" and "closed", or... at least "in" and "out." Where this plunger is located is below the carburetor, close to the exhaust manifold, towards the back/passenger side of the bay. Depending on which hole you put this pin into changes the position of the plunger. I don't know if the plunger should be out and be pushed in (by the car, however it works) or be in and be pulled out by the mechanism.
In order to change which hole the pin goes into I have to remove the entire carb and that ugly chunk of black plastic - I don't want to do this if the plunger happens to be emissions and or useless.
My concern is that the position of this plunger (as in I chose the wrong hole for the pin) is making my FB run on only one rotor. I don't reeaally think this is what's wrong but I felt it was worth covering.
While warming up the car will die when it his about 1k rpm, and won't maintain idle below 2k.
Once I get going it's obvious I've only got one rotor working. However when I put my foot ALLLL the way to the floor in any gear I can feel and hear the second rotor come in to action and it feels just like any stock 12a FB should. Both jets spray just fine when I press down on the mixture (or idle screw - I forget which one it is - it's the flat head one)
So! My ideas so far are: Carb needs to be rebuilt for some reason; Mystery plunger is causing something to not deliver fuel properly; Timing needs more adjusting (seems like a stretch but hey it's an RX7) and I don't know what else.

Edit - I was able to get a picture:

 

So Kurt Robertson says the primaries are plugged. They need to be blown out and the bowls need to be cleaned.
Off to find a diagram of how to do this.
Any other advice is greatly appreciated!

 

'Flooring it' is when the secondaries come online. If that is the only time you have fuel to both rotors, it means you have a clogged or malfunctioning primary injector.

 

i'm pretty sure that that's the valve that's supposed to stop it from backfiring when throttle is closed and the car is slowing down in gear. if your car is really only running on one rotor until the secondaries come online, then i doubt that valve has anything to do with it.

i would tend to agree that the carb needs to be thoroughly cleaned, or you need to get it rebuilt. you may need to remove the top cover to clean it.

 

try this: https://www.rx7club.com/1st-generati...rotor-1067793/

 

Thanks guys!
The guy who sold me the motor I swapped in told me he spend years addressing the exact problem when people brought their 12as into Mazda to get serviced still haha.
I have a buddy who's a little more familiar with carburetors that I am. I have a good idea of what needs to be done - just not exactly how it all comes apart.

 

So I pulled the primaries, secondaries and the ones inside the float bowls. I cleaned what I could and blew out everything with a compressor... However I'm still only running on one rotor.
The rear rotor kicks in sooner than it did before - I don't have to floor it to hear or feel the rear rotor, but I do have to give it enough gas to rev to about 6K.

Any more Ideas? Do I just need to keep pulling, blowing, sucking, f******, hoping, and trying?

 

rebuild it.

 

Rebuild what? I've already had the carb apart a few times. I'm waiting on a new float bowl gasket because the one on there now is kind of fucked up.

I realized that because I don't have the air pump in since the swap there was a massive vacuum leak there. I've plugged it temporarily and the large hose in the back as well and now the car idles at least.
So I think it's just vacuum leaks, now! I can't tell if my new intake gasket is cracked - but I don't think it is. I'll be replacing the float bowl gasket in a couple days.
Any other "duh I should have seen that" vacuum hoses I could be missing? Kurt Robertson said that it sounds like the problem now is just vacuuuuums. Every time I find one it runs better.

 

i was saying rebuild the carb, but your last post made me go back and read your original post.

i somehow missed this. maybe i got too sucked into all the "running on one rotor"-speak. either way, it does point to vacuum leak(s).

find them and fix them. until then, it doesn't make any sense trying to diagnose anything else involving the carburetor.

 

Okay. I've looked into properly removing the rats nest and routing the remaining vacuum lines properly.
The shutter valve is taking kind of a lot of force to open and close, though. What's the best way to get it to stay open and seal up the vacuum leaks there? I can't quite find that exact information.

 

IT RUUUUUUNS!!
I realized a hole I thought was in the ACV was actually not the ACV and I had completely overlooked the 1/2" hole in the back side of the ACV. So I plugged that hole and it immediately started and idled.
The carb needs to come apart again for the new float bowl gasket and to hook the choke cable back up properly.
I need to figure out what vac lines are needed and find out how to make the rest of my gauges (namely the temp gauge) work again.