Captain Obvious

Nice work. That's gotta be waaaay better than what you started with!

Haha!! I'm not looking for any promotion. That just means more responsibility for not enough pay. I like it right where I am. Good luck with the project and remember... If I'm ever in Barbados or Jamaica, you're on the hook for the tour!

Bummer. Off with her head! If we weren't so far apart, I'd be more than happy to give you a hand getting this thing into tip-top shape.

I took another look at some of the other wiring diagrams (75-78) and verified that there is never a direct connection between anything and the battery positive except for the starter. Everything else is connected through the a fusible link. Take a look at the 75 wiring diagram and trace the white wire coming off the starter solenoid. It goes one and only one place, and that's to a fusible link. I didn't look back beyond 75, but I did verify 75 through 78. Makes sense to me and I wouldn't change that. I've never looked into the "fuse upgrades" that others have done... Is it standard procedure to eliminate that function as part of the upgrade?

I wouldn't bother changing the wire sizes there. Is there some reason you think you're in need of thicker gauge there or just thinking that since you're in there anyway? I mean, it won't hurt, but I don't think it's necessary. Remember, just because your alternator is CAPABLE of putting out 80A, doesn't mean that it WILL. It will only do that if you're running 80A worth of load, and that will happen... well, probably never. Hopefully never! And speaking of which... I'm concerned with the way you've drawn the wiring connection between the alternator and the battery. In the original system, there was a fusible link between the alternator and the battery. I think that's a good idea. I'm much more familiar with the 77 system than the 75, but I took a quick look at the wiring diagram and I think the 75 has one between the two as well.

Yeah, I'm sure you've thrown off the whole sensitivity of screw movement vs. mixture change because the holes are busted through. I'm guessing they're much more sensitive than they used to be. A couple notes on the pic I posted... For a sense of scale, the tip of the idle mixture screw is maybe .020 and the hole is maybe .040? Also, you figured out that I didn't include the spring or sealing washers and O-ring on the mixture screw, right? Took 'em off for the photo. They're probably very similar to yours. Take a deep breath, get them set as well as you can, and (if you can't get over the internal knowing they're like that) keep your eyes open for a replacement set. What's a set like that cost ballpark?

Here's a pic of a (non-Weber) carb where I have cross sectioned the body to illustrate the idle passageway details. This is probably very similar to what you're dealing with inside:

Well, unfortunately, my suggestion would be to either live with it the way it is or get replacement carbs. The ones you have are "repairable", but not without extraordinary means. If you can adjust the screws so that it idles OK and the plugs look good, then that's about the best you can do at this point. I know it's eating at you just knowing the damage is in there, but unless you've got the machines to do it and your labor time is "free", it would cost way more to fix those than to replace them.

I've messed with similar idle circuits on other carbs (other than Webers) and they're touchy. There's so little flow at idle that the geometry really matters. I feel for ya. That's no fun.

Maybe the valve was sticking in the guide as well and if the rocker pushed next to the valve stem (instead of ON the valve stem), it might have released the keepers. In any event, I'm thinking that trying to get a look at the piston top would be a good idea.

Man! You've got the worst luck... It's like you just can't catch a break! I'm a little confused about what it was that caused this failure. You said the rocker adjuster was loose and walked it's way back down into the head until the rocker became so loose that the rocker wasn't retained enough anymore and fell out of position. That can explain how your car got off it's rocker, but what's your theory as to how the valve keeper split collets came out? I'm thinking that those split collet retainers should never come out as long as the valve stem is help in tension. Maybe the rocker flopping around in there hit the side of the washer on top and released the tension on the keepers?

Excellent. I don't expect any issues. The only difference I can see between the two systems is that the Z has the vacuum sources for the two solenoid valves in series, while the ZX has them in parallel. Shouldn't matter though since the only time the FICD is actuated is when the system is calling for A/C. Not sure why they put them in series in the first place. Glad you'll be looking into this.

Yes, that tube around the back of the block carried water that passed through the original manifold back to the water pump inlet. With your new manifold, I'm assuming there are no provisions for water heat? I'm no cooling system expert, but I think it's important to have a small amount of flow through the thermostat housing, even when the engine is cold. If that area is completely stagnant, then you run the risk of overheating because the thermostat won't be subjected to the hot water and could instead be sitting in a stagnant cold pool. I believe most thermostats have a small bypass hole built into them to allow for just this kind of issue, but I wouldn't completely block off all those path(s) without first confirming that is the case. Eventually heat will make it's way into that area through conduction and eddy currents, but if you don't ensure some flow somewhere prior to the thermostat getting hot enough to open, it may be too late by the time it does.

Yeah, I was mostly kidding on the crowd funding a traditional mold for the dash. At $100 a piece, it would take 500 of us to come up with the 50K tooling for a traditional mold. I mean, I'd definitely be in for a hundred bucks, but at that rate, I don't think it's possible. I'm surprised someone hasn't molded a fiberglass shell that can be backfilled with polyurethane foam and foamed into position on the existing metal skeleton. Or foamed into place on a skinned original dash ("skinned" as in "had the original black covering removed, but the remainder of the entrails remain).

I agree and have considered the same modification. I like the 280ZX version because it's got the solenoid valves built into it. The only time the vacuum does anything when the system is in transition. When you push a button and change a position, it'll consume vacuum, but once the transient has past and everything has reached it's new desired position, the draw out of the tank should stop. I'll differ from Chas above and say that the only time there would be a problem would be when you play with the controls WHILE you are at full throttle and don't have enough manifold vacuum to refill the tank with vacuum as you consume it. (Negative sense on the "refill" or course... You know... "Refilling a tank with vacuum??" ) It would be worth testing, but I bet it'll work fine. You can get all the testing stuff worked out before I get to installing A/C!

Haha, well yeah... It's a 555! I thought you were looking for super simple simple. If you were willing to put something together using a 555, we could have come up with a solution a page ago.

I'm in for $100. You get thirty of us and you've got $3K you can drop on tooling.

These are not the wires you're looking for. So now while you have those connectors loose in hand, you can make sure the polarity is correct for LED's. Probably easier now than once you have it all buttoned up. I know you aren't going to use the one for the A/T transmission selector, but the other one is for the HVAC display panel, right?

Yup, those are the two I found. I didn't have time to put together a pic for you earlier today and I'm glad you were able to find them without one. Happy to be of service. By the way, in your original post you mentioned a "green female" but what you actually hold in your hand in the pic (and what is on the wiring diagram) is actually a green/white female. I knew what you really meant.

I believe the pair going to the 2 position connector are for the "control panel illumination lamp" and the other pair of independent wires are for the "indicator lamp A/T only" I believe I have found both on the 75 wiring diagram. One of them is directly below the fuseblock on the diagram and the other is horizontally to the right from the first one. I'll clip a pic from the wiring diagram if you can't find them. Let me know.

Exactly. I try not to think about it.

I passed on the chance to buy a Dino a bunch of years ago before the prices shot way up. I kick myself regularly. Thanks for the reminder. On the good side, if I had bought one, then I wouldn't be here to pester youse guys.

I understand. I probably get my hands dirty more often than I should.

Excellent. So you already got a good handle on the measurements stuff. Better than I do, I'm sure! I'm a little concerned about the plan to use a drill press and a hack saw blade to make the grooves though. I understand you gotta make do with what you have available, but O-rings are one of those things where a thousandth can really make a big difference and I'm not sure you'll be able to achieve the level of precision desired to make this work properly. Fit and finish are both important. Do you have any access to better facilities in Barbados? Maybe you could take the parts to one of your metrology customers with some machine tools and tell them it's a test piece to make sure they've got their calibration processes under control? I've been to Bridgetown. I wasn't there for anything industry related so I wasn't looking, but the city is big enough that there has to be other means available. For a cost of course.

Thanks for the update. Looks great so far. When do you think you'll have the big reveal of the finished product?