Thermal Wax Valve?
 

I recently acquired a 93 automatic with 91,000 miles that had not run in 5 years. I was able to get the car started quite easily after putting ~1/2 oz of oil into each rotor housing, turning it over by hand, and replacing the fluids/plugs and wires.

However the idle is quite high even when warm. Could this be the thermal wax valve? Is there a comprehensive how-to on adjusting all of the crazy cams an adjustment screws on the throttle body? Could I test the thermal wax valve by boiling it in water?

Thanks!

There are a lot of things that could cause high idle. If you haven't already, download a copy of the Factory Service Manual from the 3rd Gen. FAQ at the top of this section and go through some of the troubleshooting.

Also any mods? And how high is high? What rpm are you seeing at hot idle?

Check all your basics 1st, vac lines, intakes,..etc..then move on to the bigger parts

Hot idle was at about 2k RPM last time I had the car running. Zero mods, totally stock. I was able to lower the idle simply by moving one of the throttle linkages on the right side of the throttle body down by hand, and it would drop the idle down to ~900. But as soon as I rev the engine with the throttle pedal, it would get stuck at 2000 again. Looks like the thermal wax valve is not extending(?) when it gets hot maybe, because its not even touching the adjustment screw. Unless I have that backwards - should it compress when hot? I need to go take another look at it. I have been so busy stripping out the interior and cleaning everything that I haven't had a chance to fire it up again.

Make sure your throttle is moving freely and that the cable isn't binding.

Idle can be complicated on this car and made worse if the previous owner started jacking with things. I did find this thread that might be of help... https://www.rx7club.com/3rd-generati...issues-762531/

One thing I can comment on from personal experience is that the idle air control valve can get dirty over time. It's easily removed with two 10mm nuts and a single connector. A little carb or brake parts cleaner and maybe a spritz of WD works pretty good.

OK so I have finally gotten back to this after several months of suspension/brakes and interior renovation.

The thermal wax valve is not extending, so the fast idle cam in not disengaging. I removed the valve and put it in boiling water and it extends about 1/4", so it appears to be working. So it would seem that I am not getting coolant flow to the TB. This seems bad. Any ideas? Clogged hose? Bad water pump? I haven't driven the car yet, just idled in the driveway. The temp rises, fans turn on, and then turn off a minute or two later. So I believe coolant is circulating through the rad, just not the TB.

Mmmm, a bad AWS solenoid can run idle up but generates a CEL. But you have none...correct? Hard to imagine that flow is blocked to the TB unless done purposely by a PO. Is the return hose going to the rear of the engine getting warm?

Thermal Wax Valve
 

I had a similar problem: RPMs stay high even after engine comes up to normal temp. Turned out to be a bad thermal wax valve. I replaced it and things got back to normal. However, it can also be other things as stated above. You may want to try some of them before you replace the wax valve.