Help, Hose on Back of Compression Tube
 

As a background, I have owned two FCs an N/A and a Turbo II, I have also had an RX8. This is my first FD which I picked up a few weeks ago as a Non-Running restoration project. It is a 94 Base Model FD3S.

I finally got the car running today so that I can warm it up. I plan on doing a compression test tomorrow.

The problem, well more of a question is What is the Hose that is suppose to be connected to the back of the compression tube. I have done so many searches and I kind find almost every whose and what it does on the care except for that one.

1. What is the hose on the back of the compression tube?

2. Is it a problem that it is not currently connected or on the car at all?

3. Is it a problem if the whole is not sealed off well?

It basically looks like someone just jammed a bolt into the nipple on the back of the intake compression tube, and I can't tell if it's leaking or not. I know the vacuum system on these cars is very finicky and want to know if I should replace the line and make sure it gets connected properly.

Thanks to everyone and anyone whiling to answer this question.

That hose is for the Accelerated Warm-up System (AWS). Or more prescisely it leads to the solenoid under the Upper Intake Manifold. Most owners (apparently including the pevious owner of your car) remove it. The system causes the engine to go straight to a cold start idle of ~ 3k. It was emissions related to make the engine/cat warm-up faster but obviously not really good for the engine.
Yes, that nipple can be removed or properly blocked off so you don't have a massive boost leak. Back when I still used the stock compression tube I think I sawed the nipple off, taped it for a pipe-thread plug and re-painted the tube to make it look nice. To remove the system properly the solenoid is removed ala a block-off plate. Scroll down to the appropriate AWS plate for a picture here: Banzai Racing FD Block-Off Plates Location

Thank you for the information. Now to follow up though, I did get the car started but the car will not go under 3k RPM at idle. Could they have done something wrong that is causing this?

When I removed mine, I removed everything. So I'm not sure what would happen if don't remove the solenoid properly with a b/o plate.

So I ordered the Banzai kit you recommended and got it today. Do you mind if I ask you what items I can eliminate without causing a check engine light?

Are any of the items removable that will allow me to pass smog?

I don't intend on using them all, just what is most recommended, so any input would be greatly appreciated.

Only thing I can think is that the thermowax is causing the throttle plates to stay open. Check to see if the water lines are hooked up to the backside of the throttle body.

you got Cruise control on that car?.
check to see that the cable is not tight and keeping the TB open.