fuel rail and pressure regulator suggestions-78 280Z

[Dave WM]

prob best to just do one thing at a time, since you already removed the BCCD function I would suggest you follow CO advice the make the  block off work. I was just thinking out loud about modification in general. Best thing is not to do a lot of changes at once, too many varibles to keep up with.

[Yarb]

I’m headed to my garage and was going to remove the TB and plate. I assume there are ports visible that need to be capped before reinstalling the plate? If not is there something else to look for? My FSM is at the shop and Hopefully it will shed some light on this. 

[Captain Obvious]

Yeah, with the throttle body upside down and the plate removed, you should see the holes.

I've never made a block off device for the BCDD and the only easy suggestion I have is to fill the whole lower cavity with RTV to seal the hole and then put the plate on. Really rough way to do it, but certainly simple. Just make sure you don't squeeze RTV up into the throttle body where it matters.

I've heard of people taking the throttle body off and welding the hole(s) shut.

[Yarb]

I’ll let you know what I find. Thanks again. I just want to hear it idle!!!

[Captain Obvious]

Here's a pic of what you'll be looking at. The large hole no the left of the pic leads to the front side of the throttle butterfly plate and the hole right in the middle leads to the back side (intake manifold side) of the plate. The BCDD plunger is a valve that regulates the air passing between those two holes. Problem is you completely remove the plunger so those two holes are wide open to eachother.

Figure out a way to plug at least one of those holes and then put a sealing plate on. RTV gooped into the holes should work, Just don't start the engine until it cures so you don't suck still soft RTV into the intake manifold.

Whipped up a quick sketch to show what's going on. Fill the yellow cavity with RTV maybe? :

[Yarb]

Awesome thanks, I might get creative and find some small rubber plugs with the silicone. Would it hurt if i plug both

[Dave WM]

8 minutes ago, Yarb said:

Awesome thanks, I might get creative and find some small rubber plugs with the silicone. Would it hurt if i plug both

seems to me for testing a simple rubber plug that is cone shaped and retained the block off plate should do.

[Yarb]

Good idea less messy if plate holds pressure on the plugs

[siteunseen]

Isn't there a small hole before the throttle plate that needs to be filled in as well?  @Captain Obvious

[Yarb]

There is a pin hole and a large hole next to it. I thought that fed the BCDD. Ok fished it out with weed eater line large hole in front goes to large port in bcdd, got it plugged small trace of black silicon on my line when I pulled it back. Small pin hole goes to the dead end loop under the plate. The plate cap will seal that. Put a small amount over the pin hole inside the bcdd chamber just in case. Everything can be cleaned up if necessary in the future.

[Captain Obvious]

3 hours ago, siteunseen said:

Isn't there a small hole before the throttle plate that needs to be filled in as well? 

Yes, there's actually two of them. one in front of the plate and one behind.

But I believe those two small holes will be blocked off by the simple plate. It's the big ones that need additional work other than just a flat plate.

[Yarb]

Got them both plugged and sealed. Clean the plugs and give it a try.