Captain Obvious

Disconnecting the wire will enable the BCDD (which is the wrong direction and not what you want). If you want to completely disable the BCDD, turn the adjustment screw (#6 above) counterclockwise (when looking at the screw head). In fact, you can take that screw completely out. If the diaphragms inside are intact, the BCDD should be disabled completely. Of course, if one or more of the diaphragms has a hole in it, there's no telling what that thing is gonna do. Could disable, or enable it. Also, if there is a goober of carbon gunk holding one of the BCDD valves open, then things get unpredictable as well. To test if your problem is the BCDD, you could probably take off the rubber boot on the front of the throttle body and put a small piece of tape over the BCDD holes. Put the boot back on and start the engine. I wouldn't rev the engine for fear of sucking the tape off and down into the engine, but as long as the throttle butterfly stays closed, you would be OK for just a test. We'll figure this out!

Sorry, but I'm not sure I'm understanding... You are correct that as long as it's plumbed the same as the stock can, then that Sentra can should work just fine. You need three connections to the carb can. A vapor IN connection, a vapor OUT connection, and a CONTROL signal connection. The vapor IN connects to the overflow/separator tank thingie inside the right rear quarter panel. The vapor OUT connects to any constant always present vacuum source like the intake manifold, or the balance tube (if you're running carbs). The CONTROL signal connects to the ported vacuum signal that is also used to control distributor vacuum advance (high vacuum just above idle and no vacuum at other throttle positions). If you've got those three connections to it, I don't think the physical location of the can matters. I was just questioning if you were planning to have access to that ported vacuum signal. I wasn't sure if you were planning to run the original throttle body, or switch to carbs that did not have that signal available.

Well then I'm not sure I understand your question when you asked "To remove the BCDD is simply plugging all the vac lines to it?" I thought you were asking if you could remove it from the system (disable it) by plugging the vac lines that go to it. Were you suggesting a way to disable it, or are you suggesting taking it completely off the bottom of the throttle body and replacing it with a solid block-off plate?

About the charcoal can... They use a ported vacuum source to actuate the canister purge. They don't want to pull air through the can at idle, or at WOT as it is essentially a controlled "vacuum leak" and could adversely affect stability at idle and performance at WOT. The only time they purge the can is at light cruise. So... With all the changes you're making, are you planning to still have access to a suitable ported vacuum source peaking at light cruise?

Well I did a little digging to try to refresh my memory on exactly where I removed metal to allow my parking brake handle to sit lower, and I still don't know. A little embarrassing. I took a couple pics of the assy on the car (with the parking brake removed), and it looks like I may have cut a new rack gear or two at the bottom of travel. Kinda hard to believe, because the teeth look perfect and I don't remember putting that much effort into it! If you want to wait, I've got a plan. This past summer, I bought a new rubber seal for the parking brake pivot ball under the car, and I'll take this off season opportunity to replace that seal. In order to put the new seal in, I'll pull the brake assy and take some pics. However, if you've got the ability and opportunity to lower yours by relocating the mounting bolt hole, then that should work great too!!

I don't know anything about 79, but for all the previous years, it's not a simple matter to disable the BCDD. 75-78 has one wire going to the BCDD, and that wire needs to have +12 on it to disable the BCDD. Meaning that if the wire is disconnected, the BCDD will be enabled. And as for vacuum connections... There are no externally accessible vacuum controls for the BCDD. There are two vacuum ports coming off the throttle body that LOOK like they might have something to do with the BCDD, but they do not. They are both ported vacuum sources that go to small holes in the throttle body bore to control distributor advance and EGR operation. Even though they look like they are for the BCDD, they are not. All the BCDD vacuum ports (both control signals and operation vents) are located internal to the throttle body casting and do not come out to the outside world at all. Like I said, I don't know 79's details, but if the BCDD is on the underside of the throttle body like 75-78, then I would assume it's pretty much the same.

Here's a sketch of what I did to the parking brake assy. Note that it's a hardened pawl on a hardened gear so a file will just skate. You can't do it with a simple file. I didn't trust myself with a grinder, so I used a small square profile diamond file. I'll see if I can get an actual pic of what I did, but in the meantime, this should describe it. So at the "new" bottom of travel it doesn't click because there aren't any teeth, but you can adjust the at rest position like this. After making this mod, it made the addition of my return spring (other thread) even more necessary:

I don't know what happened with the original pics, but here are some replacements. Top side: Bottom side: Close up:

Yeah, I agree. That's exactly why I went through the effort to move mine up there. I wanted to get rid of the rats nest of hoses under the dash and simplify everything under there. I figure the fewer separate hose lengths and fewer clamps, then the fewer leak sources. Only reason I would use to justify putting it under the dash is that I believe the Escort core and the newer plastic bodied ball valves to be more reliable than the old stuff. I think at this point, if I used a new style ball valve and figured out a way to stuff it under the dash, I don't think I'd ever have to mess with it again. It would become the new owners problem at some point hopefully long in the future.

No, I think it was material off the ratchet gear itself. I'll take a look today and see if I can refresh my memory. Sad part is I've done two of these now (mine and my buddy who was with me at your place), and I don't remember the exact process. Some stuff you just don't think is ever going to come up again...

1) One end goes to the charcoal canister, and the other end attaches to the complicated 74 balance tube. 2) Charcoal can could help with gas smell, but won't do anything for vapor lock. All years have gas tank venting one sort or another... The difference is what they did with the fumes. Prior to 74, they "stored" the gas fumes inside the engine block, and after 74, they routed them to be grabbed onto by activated charcoal in the carbon can. I'm not sure about the very early years (like 70), but prior to the carbon canister, they used a device called the "flow guide valve" which directed fumes into the non-running engine crankcase. In 74, they updated the system to the charcoal can. Does that help?

Oh, and I forgot... I didn't like the perpetual Viagra posture of my parking brake either and I lowered mine too, but I did it a little different. I ground a little material metal off the parking brake assy where the two parts come together and limit the down travel. So now mine still uses the original mounting holes, but it lowers a good bit farther down than original. I don't think I have any pics, but I'll take some when I get the chance. I thought I had some in my parking brake spring thread, but not only didn't I mention that, but all my picture links are dead: http://www.classiczcars.com/topic/49952-parking-brake-handle-return-spring/ Not sure what happened to the pics...

Whoa... They managed to stuff an angle grinder in the original harness? Those Germans thought of everything!!

I haven't tried it to confirm, but I believe the studious and creative Z owner would be able to find off the shelf molded hoses that could be modified to accomplish that.

That top tube is the purge line from the carbon canister system. I think the 73 still used the flow guide system and in 74 they updated to a full blown evaporative capture system. Meaning... I think that fuel rail is from a 74. But the bottom line is... Unless you're running a charcoal canister evap system in the stock location, you can cut off that top tube with no problem.

The technical term is "AFDB" - Aluminum Foil Deflector Beanie Details can be found at http://zapatopi.net/afdb/ - An Effective, Low-Cost Solution To Combating Mind-Control And I know you are quite good with mechanical stuff, but just in case... Here's construction details: http://zapatopi.net/afdb/build.html

I'm also sure that, if one desired, it would be possible to use a newer style water control valve and mount it under the dash in a similar configuration to the original. Some of those valves come in 90 degree versions, and I bet someone could figure out a way to connect one of those up and keep the temp control valve on the passenger side of the firewall using all easy to find components. I haven't done it personally, but I believe the studious and energetic Z owner ought to be able to find a way to make that work.

I used a different version of those connectors. I believe it is VW. Instead of one long lock release bar on the side, it has two lock release tabs on the ends. The ones with the one long bar on the sides are good and much better than the originals, but I think the ones with the two tabs on the ends are even better. Don't remember if I've posted pics before, but these are what I used. Didn't work well for the water temp or thermotime because of clearance issues, but for the injectors... I love 'em!! :

And from what I've seen, sometimes they used a semi-circular washer to clear the rounded fillet at the bottom of the fender bend.

Nice. I've seen catalyzed paint in a can like that at Eastwood (2000K or something like that). I think that technology is really cool.

Sweaty and Dave, Some time ago I moved my water control valve up into the engine compartment, so I'll just reconnect to that location as before the Escort core. Because of the work previously done, that part of the job should be easy. One hose will go straight to the head with no splices, and the other hose will go to the Acura valve in the engine bay. I wrote up the details of that valve relocation in this thread: http://www.classiczcars.com/topic/44009-heater-water-****-valve-relocation-project/ Here's a pic of the valve in the engine bay and there are some other pics in that thread:

So I started messing with the hose connections to the Escort core. I realized that it would be easier if the core were located higher in the air box. So I pushed the core upwards until it reached the original upper locating tabs inside the air box. Here's the core in it's new upper location. Note the holes for the tubes from the first attempt lower position: And then I started playing around with hose connection alternatives. Here's one option... As I was messing with the hoses, it appears that I could use simple generic ninety degree hoses on both sides if it weren't for the fact that the feedthrough nipple assy turned the one hose downward towards the floor. If both feedthroughs were straight instead of bent, it would simplify the hose bends. My feedthrough is all rusty anyway, so I toyed with the idea of making a new one to replace the rusty one. I even went so far as to build myself a crude bead roller. Here's one of my bead rolled test pieces showing what could be done with a redesigned feedthrough assy: But then, as I was toying with the idea of remaking the feedthrough assy, I realized that I could get rid of the metal feedthrough nipples completely and just run the hoses directly through the firewall like they did on the 240's. So I made the original holes a little larger with a Greenlee chassis punch: Popped in some grommets of appropriate design, and ran the tubes straight through. Two generic ninety degree hoses (cheap!!). Here's some pics the hoses straight through the firewall without the rusty metal feedthrough nipple:

Haha!! Well you certainly blanked me with that one and right after I posted that, I realized took the wrong tact. I shouldn't have suggested it wasn't popular and tried to hide behind a shroud of obscurity... Considering it's one of your top ten, what I should have done was watched it!

I did not get that reference fairly, and have to admit that I had to look that one up. Methinks you were one of a very select few that actually SAW that movie!!

I would do what siteunseen did... Give it a half turn one way, and if it fixes it or makes it better, you're going the right way. If it gets worse, go the other way. And if you're going to use a Fonics Monkey, make sure have good music on hand. I believe Dio would be appropriate.