this is all great info...cause I am having similiar problem and can't fix it as yet. My problem is I drive the car for 15-20 minutes, come to a stop light and the idle starts bouncing around. I have to rev the engine to get it back down to the 800-900 rpms, otherwise, it is bouncing up and down.....and even sometimes levels out at 1800rpms and just stays there...weird??...any fixs to that ???..I replaced the fuel filterm clean out the dynamic chamber and bac valve, did not work. I am thinking of the plugs next....what do ya all think??...you all give GREAT info...thanks...Hey CLEAN, if you fix your problem, let us know what it was...ok?? thanks...cjf.....

 

To check your shutter valve, just see if air is sucking down this tube at idle.



If it is, then your shutter valve is bad. Take the hose off the bottom if the air cleaner box, and shove something down it to plug it up. The shutter valve just gives extra air tot eh back rotor to stop backfiring on deceleration. You don't need it all that badly. Many of us are running with them plugged as they go bad every 80k miles or so.

 

Cool, thanks, I'm a visual person, pictures REALLY help!

I'll have to check it tomorrow, but I'm pretty sure it's not sucking anything down there at idle, but I'll check it out. This is frustrating 'cause I'd like to get it fixed before I cancel my insurance for the winter.

Clean

 

Forogt to add, it sometimes may make a honking noise or some kinda funny air noise. Mine sounded like a reterded goose stuck in a wind tunnel. But it may not make any noise, so just check for air.

 

Thanks Pele, it is making a funny noise, it's almost like a clacking noise out of the carb, and it tends to shoot stuff out of the carb every now and then. I'll try to check the car when it's light out tomorrow, and I'm not afraid of waking my neighbours up.

 

I'm going back on what I originaly said. Clean, from your last post, it sounds to me like you probably have lost a seal... did you do that compression test?

 

Wow, this sure is a long post. Well, from what ive read so far, clean, only checked the compression on the rear rotor, I would suggest to check the front(which seems to be fine) and then the rear, to compare wooshes.
I dont recall reading if you had headers or not, but if you do, do they give off a red glow(really hot) when idleing??
My friends rx7, had some weird symptoms, one of them was that it wasnt getting any spark off one of the coils, the one furthest from the battery, i think it was the trailing. But I would get a spark off 3 maybe all 4 plugs at the cap. When i first removed the plugs they all looked really bad, but the rear ones where filthy as hell. They had this stuff that looked like oil mud. Since then hes replaced the coil, set the timing and changed the plugs and the headers dont glow anymore. So many things were tried and done that its now hard to see what actually helped what.
I hope this ranting makes sense and helps you out a little. Or at least give you a little more hope.