I’ve got a 1986 na rx7 and I’m having a little trouble with my idle. I’ve got multiple symptoms.
So when I first start the car, it screams, goes up to like 3,500 rpms. If I touch the gas it’ll go down to its “normal”, so I’m guessing that’s something with my throttle position sensor. But that’s not actually a big problem because it’s fixed so easily, and I only mention it because I think it has a slight chance of being related.

The car also has a very high idle when first starting, (this is after I press the gas) it jumps from around 1,500 to 2,800 maybe (usually over like 2,200). it settles down after a while, but I’m wondering what’s causing it.
My biggest concern actually lies in a LOW idle. Once the car is a little warm, my idle drops down to about 600 rpms and continues to jump from around 600-800 and it runs pretty rough.
I’m thinking these issues are all connected? But not sure what’s actually causing them. What’s causing all this fluctuation? Any help is appreciated!

Does any of this even matter? I feel like I’m hurting the engine with this extremely rough/low idle.
Also when driving it seems to run like a dream. It’s only the idle that’s having issues.

 

the fast idle when you start it warm and cold are normal. so i would start by just setting the warm idle.
the manual has a couple of pages on it https://foxed.ca/index.php?page=rx7manual

 

My '87 GXL acts exactly the same. It is all normal. (I'm the original owner.)

 

The fast idle is set from the factory like that as stated above. Also considering mine does the same thing (low Idle) and there are 5 pages worth of thread titles with low idle in them, I would say yes. This can be a serious rabbit hole if you don't do the set procedure correctly. Also if, like mine, the adjuster screw doesn't actually adjust the idle. Perhaps I am doing something wrong. I have way to much brake, suspension and underbody work to do right now. Otherwise I hopefully would have had it fixed already, a task for another day I guess.

Just a word of caution, read as many posts about this as possible and follow the trouble shooting methods in the FSM, if any, without skipping any steps before starting this. There is a long list of things that will cause this, if I am remembering correctly. Leaky injectors, vacuum leaks, timing and others. Hopefully it is just an idle set and nothing else for yours. Good luck with getting yours fixed.