Hello everyone, I finally decided to see if I can finally solve my problem of not having any secondary boost. Started by taking off a portion of the intake piping and the pressure chamber to just look for any obvious problems like a broken hose. What I found instead was a broken check valve and a connector without a home. In the photo I numbered a couple of things.

1. The empty vacuum line that I believe is supposed to be there based on the vacuum diagram.
2. Some random line with what appears to be a screen on the end, I thought it that the Charge Relief solenoid was supposed to be there but that should be the black box directly behind it right?
3. One of the vacuum lines to the pressure tank.
4. What the second pressure chamber line went to through the check valve.
5. A random connector that was stuffed behind the air pump not plugged into anything.
6. The potential culprit for my boost issues.

Also, I am planning on doing all silicone vacuum lines but I thought it would be better to try and get the second turbo working first before taking all the vacuum lines off and potentially causing another problem in the process. Any thoughts and help are appreciated, thanks everyone.

 

There are plenty of threads on this site to help you out. Here is one to get you started:

https://www.rx7club.com/3rd-generati...-stuff-802060/

As for some of your questions:

1) This is normal it is the empty pipe in the diagram
2) This is from the CRV. The line circles around to the holder. (not sure why it is this way).
3) This is is for the vacuum chamber. The one next to it (closer to the alternator) is for the pressure tank.

I actually have mine all apart now so it is easy to check

Get you UIM off and start testing. Good luck!

 

You are all on the right page. Really, you just need to replace that failed check valve.

The blue connector is the EGR switch connector that most cars don't have, it's supposed to be unplugged, you are good there.

I will PM you about my check valves.

For the vacuum lines, leave the ones that are on there and are fine alone. No sense in replacing perfectly good lines - they may be hard and baked on there, but they are doing their job and aren't causing problems. Replace the lines going to and from the pressure tank and with the check valves in them with silicone. Boost controller.com has top quality silicone hose, you need 20 feet of 3.5mm and 10 feet of 6mm to do a whole engine so gauge how much you want to get off that.

Dale

 

Ok, so I replaced the check valve and hose then went out to see if that fixed it. The first time I felt the transition into the second turbo was amazing, I've never had the second turbo working since I bought the car and its amazing how much of a difference it made. I didn't realize that it was that way until my second month owning it that something didn't seem right.

Nmoffatt, thanks for the thread, that will be super helpful in the future.

Dale, I bought the Viton check valves from Banzai when I bought a Walbro 255 in anticipation for this job because I saw someone or yourself mentioning them being needed. Similarly I also bought the exact vacuum hose that you just recommended above due to another of your replies to another post.

Thanks for answering my questions. I'm going to go out and enjoy my car as much as I can in this Southern heat with no A/C, the next project to research.