Captain Obvious

Yes, I mean RTV. I'm particular to "Permatex Ultra-Grey" because I've found it to be the firmest (highest durometer) once cured. And in this application where you're trying to seal that flimsy, probably already bent flange using a thin paper gasket, I think the high firmness is especially valuable. It's not really gasoline rated, but in this application, I would still use it. If everything is working as intended, that gasket should be a seal for air, not gas. I don't think a dry paper gasket is going to get you where you need to be.

And to answer some of the other questions... The idle mixture screw is just a rounded nose fine pitch screw that bottoms out on a seat inside the AFM body. So I guess it could be possible for there to be crud built up down inside there that might prevent that screw from bottoming out completely? I do consider it a little unlikely though, because any crud inside there would probably be a soft carbon sticky mess of crankcase PCV blowby and would probably be smooshed by the screw tip and seal pretty well. I would consider it to be more likely that it would be to crud SHUT than crud open. And about the carbon canister, to be honest, I'm not completely positive I understand the valve in that cap completely. I mean, the description in the FSM is pretty simple, and I understand how it is SUPPOSED to work, but after messing with that diaphragm and valve in the cap for the CARB can, I'm a little unsure. I do know that the way it's SUPPOSED to work goes like this: 1) When the throttle is any position other than light cruise, everything is supposed to be shut-off and hold vacuum. 2) When the throttle is in light cruise, you should be able to draw a small amount of air through the larger vacuum line straight into the intake manifold. This is the purge cycle of the carbon canister. 3) The small control line is always vacuum sealed. You should be able to draw a small amount of air out of it with vacuum, but then it should always hold that vacuum. The part I'm a little unclear on is the purge line... Looking at and playing with the valve in the CARB can cap, it seems like it's "normally open". But then the control line also pulls it open when you apply vacuum to the control?? So I'm thinking the manifold vacuum actually pulls the valve closed to seal it. And then the control line overcomes that vacuum and opens it again? Does that make any sense or am I just making things worse?

Well that sounds promising! In my experience, I've never really liked that cold start seal in the first place. It's on the high vacuum side. It's a relatively thin, flimsy flange that is almost always bent from the force of the bolts that hold it down. It's a high surface area to the number of bolts that hold it down, and those bolts are far from the center on those flimsy wings. So if I had to have a cold start valve (which I'm not sure you do), I would slather that gasket up on both sides with silicone sealer. There's no way I would ever trust it put in completely dry. But that aside... Being in Dallas, when do you ever, ever, ever get weather cold enough to even really need a cold start valve? It's not like you guys ever get temps below freezing, let alone into the 20's*. I've removed my cold start valve and capped off the hole and haven't looked back. I think you could do the same. But (and I'm not judging) if you do want to keep it, for whatever reason, I would absolutely use some gasket sealer on that thing. If you got 13 with it blocked off, it's clear that if it's not leaking air, you're readings should be just about perfect. And don't worry about the egg at all! * Except for a week ago, right?

Sorry. Gotcha. I thought it was pebkac. Didn't know there was editing issues. I'm gonna go back in my hole now.

Hmmm... So you have the AFM gear adjusted such that cruise looks good (at 14.6), and WOT looks good (at low 13's), but idle is too lean at 16.5. And that's with the idle mixture screw turned all the way in. Well first thought is vacuum leak, but you said you're good there. Second thought is throttle position switch, and you said you're good there too. OK, so humor me since you got an A/F gauge... First thing, at idle, spray some starter fluid or carb cleaner in and around the intake tract while watching the A/F numbers. Make sure to hit the boot between the AFM and the throttle body, the throttle body butterfly shaft (both ends), and the BCDD area. Something else to try... Unplug the TPS while watching the A/F. If the switch is being interpreted correctly, it should run even leaner with that switch disconnected. You can either disconnect it, or pop the black cover off and manually open the idle contacts. Gently. And you can do the same sort of test for WOT... Drive the car around with the TPS disconnected and you should see your WOT numbers run leaner. And you're sure you've got the altitude switch in the "richer" position, right? Just tossing out ideas.

Excellent. Sounds like that will get your car to you without the moving guys killing your battery or burning out your starter. You could also still unplug the oil pressure sender in addition. Maybe give that a try tomorrow morning to see if it makes things even a little better. I mean, I think you're good enough already, but just in case you're looking for that extra push over the cliff (as Nigel Tufnel suggests), you could try that too.

@Racer X, I keep meaning to mention this... You don't always have to quote an entire post every time. You can clip it down to a smaller size, or not include any quoted material at all if it still makes sense without it. Just a suggestion.

Jayhawk, That's a great pic. I love it how everyone ended up in a Z!

Great! Last I heard, you were gapping rings. I didn't know you had the motor back together! So far, so good, huh? Excellent! So did you do a compression test as soon as you put the rings in at zero miles? Just to see?

Haha! Use the Zcon beverage budget please. I'm hoping to be able to make some withdrawals from that acct in the not too distant future!

I know just enough about the casting process to be dangerous. My understanding goes something like this... To do it "acceptably", you can watch some U-tube videos and read some websites. To do it "really well", you need to know what you're really doing. From my limited experience, I would predict two stumbling block areas: 1) Getting the large flat surface to cast properly without wavy-ness. Might be able to make a support "box" that surrounds the mold for additional support. 2) Getting the translucence and color of the casting resin right. I don't think this would be too difficult, but it would take some experimentation. As for your carbs... I've been known to put the smoke back into cycle carbs from time to time. Since I worked my carbs, my bike starts, idles, and runs perfect. Is there something specific causing problems?

Is the throttle linkage connected?

Glad to help. Oh, and BTW... There's a guy here on the forum @S30Driver currently parting out a 78. I don't know what his plans are for the car, but he would have the backing plates and parking brake arms you need. And full disclosure... He'll give me a 10% finders fee for parts he sells you. He doesn't know if yet, but he will.

Oh, and glad you got the plates off! It's often just a matter of being sure you're doing the right thing.

Well I don't know the availability of the 77-78 rear plates, but if you decide you're not going for a disk brake mod, I'd look into it. Lets see... what would you need? You would need 77-78 style: rear plates wheel cylinders parking brake arm / adjuster mechanism rubber grommets for adjuster arms where they feed through the plates brake shoes and hardware kit The wheel cylinders, shoes and hardware kits are cheap, plentiful, and easy to find. The grommets are a dealer only thing, but they're not expensive. The only parts you would have to hunt for are the backing plates and parking brake adjuster arms. You'd need to find someone who pulled those parts off a 77-78.

So I don't think the key is upside down in those pics, I think it's just rocked too far tip-down. In order to get things assembled correctly, you need that key to be level or a little bit tip-down. The problems occur if you try to put things together with it tip-up, or if it's tip-down too much (which is what I think is going on in the pic). Wally, you said that the key is stuck in that position... I'm not sure why or how that key gets stuck in that tip-down position unless it got knocked into that position after the pulley was removed and then sat like that and froze up. There's no way it was like that the day the pulley was removed. Is this something you took apart a long time ago and let sit, or is this all recent work? If that key is really stuck in that severe tip-down position it's going to be a problem.

No problem at all. I said keyway, but I probably should have just said "key". The keyway isn't the real problem... It's the key that's the issue.

So internets science for the win! Whatever the underlying process, that lens looks good. Just hope there isn't any unwanted long-term effects. On a related note since I know you like to mess with things like this... Have you ever played with taking silicone molds from parts and copying them? That light lens might be an interesting candidate.

Glad to help. So yeah, it's just age and rust that's holding it together (like me). Clean some rust and old paint off the spindle snout where the plate rides, douse it with penetrating lube of choice, and give it a whack on the back side. Out of curiosity... Why are you taking it apart in the first place? Disk brake conversion? Cleaning everything up for paint? The reason I ask is that if you already have the bearings out and those plates off, I would take the opportunity to upgrade to the 77-78 style backing plates so you can use the better wheel cylinders. I would try very hard to not go back to the 70-76 style floating cylinders. They're not nearly as reliable as the newer system. But that's just me... I've got a 77.

The key ZH is talking about is the same thing I was talking about earlier... "Be very careful of the position of the keyway that drives the harmonic balancer. Make sure it's correctly sitting in it's groove before you push the pulley (balancer) into place. If you don't you could crack the balancer when you tighten the big bolt in the front." That key fits into a semi-circular groove cut into the snout of the crankshaft. The problem is that since the key is semi-circular, it can "rock" in the groove. And if that happens without you realizing it, you may think you have the pulley fully seated onto the oil slinger, but you don't. Then when you put in the big bolt in the front and torque the crap out of it, you crush the key, mangle the oil slinger, and worst of all, crack the pulley casting. It's not pretty. So you have to make sure the key is properly located in the groove before you put the pulley on. And I would recommend you use a bright light and look down the pulley groove to make sure you see the key in there looking like it should before you put the big snout bolt in.

Yeah, that looks good. I would probably stop there. So this peroxide and UV combination thing... Is this internets science? Most times UV makes plastic worse, not better. Not arguing with the results, but wondering if the UV was really adding any value?

Yes, the seal on @Av8fergs pic looks good. Too bad the timing cover is so shiny.

Haha! I got two parts to the answer to that... First is that the pics of that backing plate work was a special situation where I had other people over for a "rear bearing party". I was doing mostly directing and telling other people what to do (clearly, as it should be). On that day, I got to hold the camera and take pics of other people doing real work. That's not me swinging the hammer, it's one of the other attendees. The second part to the answer is "I've found it worth the effort to try to make it happen." By that, I mean... I do so many car projects (that I have to refer to again sometime in the future) that I really now try to take pics along the way. Still, there are plenty of projects that, just like Jeff, I'm in hurry-up mode and can't deal with the camera at the time. And as Murphy dictates, those hurry-up jobs are invariably some of the ones I WISH I had pics of at some point later.

They are not one piece. They just need a little persuasion. Take the bolts out: Turn it over and give it a judicious whack. Don't go postal on it, but some BFH persuasion might be necessary. And here's a shot with the plate removed:

The newer ignition switches had a little set of contacts inside that would activate a beeper if you left the ignition key in the slot. They called it an "anti-theft" feature and I'm assuming that it was a reminder to not leave the keys in the ignition switch when you left the car (like anyone does that anymore...). The earlier cars did not have that feature and the little beeper switch was not present inside the ignition switch. So I don't know what year you're working on, but the wires in question are related to that feature.