Actually, a combination of questions which may or may not be related:

1. Car won't hold idle until warmed up to normal operating temp, then idle is pretty steady @ around 8-900 RPM. Unless, of course, I try to run the AC, in which case the idle bounces between 900 RPM and stall. Until warmup, idles @ about 4-500 and stalls occasionally at stoplight.

2. I noticed today there seems to be a electrical drain: Turned on wipers while parked: very slow operation -- when I started driving, the wipers sped up. Noted the voltage is well above 12 when driving, drops to 12 or slightly below when stopped. Depressing the brake causes the voltage to drop and the dash lights to dim. Again, the problem seems to lessen once the engine is warmed up. Alternator? Battery? Evil spirit?

For what it's worth, the engine is a rebuild from Rotary Resurrection which has had all the emissions gear (BAC, air pump, etc.) removed as well as the thermowax. I've had the car for a month, and the previous owner ( a forum member) says there was about 3500 miles on the motor, to which I've added ~1500.

This car will be my semi-daily driver, so reliability (and AC here in S. Fl) is my primary concern. I LOVE the car, just wish I could figure out all the little quirks! Any help is much appreciated!

-Paul

 

I'd start by checking your grounds to the engine, and maybe running some redundant grounds. Since the problem goes away when you're moving, I wouldn't think it was the alternator. I think I saw somewhere that people who've removed emissions tend to adjust their idle to somewhere around 1000. That would probably help the bouncing when the AC is on. Heck, it may be enough to fix your other voltage problems too.

 

ALternator BAD!!!...
Get a new one....or maybe it's the belt?
Either way it's not holding a charge....
someone make fun of me and correct me...

 

Problem and cause right there. If you want your engine to idle properly, don't remove the idles control devices. Pretty obvious really. Neither the BAC valve or thermowax have anything to do with emissions.

And you need a new alternator.

 

Sorry, but your car wont idle with the AC on anymore since all that stuff was removed.

 

To be honest, I wouldn't have removed any of it, it was already gone when I bought the car. I'm already contemplating replacing at least the BAC, since I believe, at least from what I've read here, that's what controls the idle under load, particularly with the AC on. Questions:

1. Can I replace the BAC alone, or will I have to replace other parts connected to the BAC? What does the BAC connect to?

2. Will the BAC from an NA motor work on the TII? They appear to be in different locations in the Haynes manual?

3. Can the stuff even be replaced without removing the motor and/or major headaches, if at all? Looking at the "emissions removal" process on the RR website, it looks like a pretty involved process.

Thanks for all the assistance. This is my second 7, but my first was a stock '91 vert, which I loved so much I decided to get another vert, and turbo SEEMED like a good idea, but being not mechanically inclined, this is definitely a learning experience. Especially when stuff isn't where the book says it should be

-Paul

 

thermowax removal is making your car idle like **** while warming up

Lesson to all reading: be really careful with what you buy.

 

Alternator bad = battery no charge = voltage problems don't go away when the revs pick up. But I've haven't experienced an alternator failure on my RX7 yet. I experienced 7 or 8 failures on other cars. Maybe the RX7 acts different, like a faulty voltage regulator. The good news is that the alternator is pretty easy to take off and most parts houses will check it for you free. Some can even check it on the car.

I'd bet a beer that the reason the electrical voltage output is low is because the engine RPMs are below what the alternator needs to output a voltage > the battery. Like maybe his gauge says 700-800 but engine is actually turning around 500 something. (yes, they will idle that low, at least according to my SAFC.) If the alternator were shot, his lights wouldn't get brighter when the revs picked up.
If that's the case, tweak your idle RPM up using the directions elsewhere on this site and in the manual, and you should be able to keep your car from dying, even with the AC on.