Captain Obvious

What is the range on the meter set on when you are taking these readings?

My thought is If the A/F numbers look that good, I wouldn't worry much about the plugs being light. I've heard (read on the internets) that the old method of reading plugs doesn't work so great on todays fuel using leaner ratios. Burns so clean that lighter colors often result. That toasty brown doesn't happen as much as it used to? How many miles you have on the plugs? I guess if you're thinking it might be a relic of a previous situation, you could buy new plugs and have a fresh read. As for the ignition box, I don't know anything about it. Hopefully someone else can chime in.

That's exactly what they did starting in 77. They went back to vents on both sides (as opposed to 75 and 76 which only had the vent on the right side) and changed the intake location from the front of the car to inside the cowl area instead. Just another reason why 77 is better.

Well (in theory) the only change you would/should see with the CARB system connected is that it should run leaner at the low end of cruise because that's where you should be pulling air through the can into the manifold. 1/4 pedal maybe? Somewhere around there. It should be a pretty tight spike as the ported vacuum that actuates the system cuts off pretty rapidly when the throttle plate isn't over the port hole.

Those numbers look great. I'm sure you're happy with that! I'd love to see how your engine dynos. Did you ever put your CARB system back together? Are those numbers with the system connected using the valve in the cap? Also, out of curiosity, can you see a distinct change at the upper end of cruise when the WOT switch closes and the enrichment kicks in?

Well I haven't gotten the insulators off the intake manifolds yet, so I don't know which side the gaskets will end up on. I do, however, have the situation with gasket material petrified onto the manifolds where the balance tube goes. I've done some work with the paint scraper razor blade, but got skittish the second time I dug in. The first time you tell yourself "OK, I slipped once... Let's not do that again." And then you do it again. I believe the aluminum is softer than the gasket material. So I haven't caused any unmanageable damage yet, but just wondering if there's a silver bullet. Granny says "no", but I'm hoping he's just not hit on it yet. Maybe I'll try the shallow pan Mr. X suggested, and maybe put the whole thing in a bag just to see what happens. Thanks guys!! So before I crawl back to my hole... There ARE concoctions sold on the open market that are named "Gasket Removers". Is this just snake oil?

@Racer X, Any clever suggestions for how to keep the gasket wet with solvent for a couple hours for it to soak? I've tried the saturated rag on top method in the past, but it dries out too fast. I don't think I want to drop the whole manifold pair into a full tub of the stuff. How have you kept stuff like that saturated?

Hahaha!!!

So I took a couple minutes (which is what I should have done first instead of asking) and Stoddard solvent is basically what they use for dry cleaning. Kinda like white mineral spirits, but not exactly. Smells (and they say tastes!!) like kerosene, but not exactly. I'll see if I can turn up a small quantity here and see how it goes. Thanks for the input!

You can reuse those spacers just fine. As mentioned above, maybe hit them on a sanding surface a little to see if they're badly warped, but other than that, run 'em. If you think they're bad enough to risk not sealing, you could put a little gasket sealer on them as insurance. For those, I'd use a non-silicone type like Permatex Moto-seal. It's MEK based and (in theory) is resistant to gasoline. So I got a question for the collective... Has anyone come up with a good "solvent" to loosen the old petrified stock original gaskets? They're hard as rocks, stuck like the dickens, and probably harder than the aluminum they're stuck to. I've got the same job ahead of me (getting spacers off intake manifolds) and I've tried the typical methods with little success. I'm looking for a silver bullet without having to completely powderize what is probably asbestos laced old gasket material. All these years of experience and I'm asking how to get old gaskets off... Kinda embarrassing.

Excellent!! Glad to hear you're getting good numbers. And remember that you're getting those numbers from a completely open loop analog voodoo box that was designed 50 years ago by some genius from Germany. Seal up all the vacuum leaks, clean the electrical connections, get the fuel pressure where it belongs, tune it (as best you can with limited options) and put it on an otherwise healthy engine. Guess what... It can work! So what's the bottom line? What general numbers are you getting for idle, cruise, and WOT? And also... in the end, you moved the AFM gear about 15 teeth from where it started? That's a lot. Do you think the AFM was messed with at some point in the past thereby changing the calibration? Or do you think that other things have just shifted so much that 15 teeth was required to bring it back to where it belonged? I should have let you borrow my AFM adjustment tool:

Well, as long as it's holding position, lets hope it's OK. So when do you get out on the road and see if that takes care of the richness at the high end of cruise?

Man.You gotta stop it with this crap. New day, new issue. I mean... I understand the phenomenon completely, but it just sounds so preventable when it's happening to someone else.

Well from the A/F test results you had from before, I don't think you bent it too far. You'll know for sure when you get out onto the highway again and get some new numbers. If it's too far, you'll start to run lean at the high end of cruise before the switch closes and adds the WOT enrichment fuel. I am a little concerned about the not holding position though... Do you think you fatigued the metal in the bend area?

Woooooo Hooooooo!!!!!

Well the "works" part is it's possible to remove that pivot point without severely messing up the rest of the firewall. So, yes, you have proven that!

You and me too, my friend!! I wish we could spend way more time together. Maybe next time, it'll be at your place.

Yes, you want to bend the arm you have labeled #2. Leave #1 alone. So by moving the actuation spot, you were able to get it out to about 3/4 full pedal? That's significantly farther then stock. Good luck with the numbers run. Hoping they look great across the board!

That is exactly what happens if the key slips out of place when you install the damper. The key rocks the wrong way in the slot, gets jammed in there, and if you keep pressing and force the pulley on anyway, it cracks the brittle cast iron pulley. Since some dampers are really hard to get onto the crank snout anyway, you might not even notice the force required to get the pulley "home". If you use the large bolt through the middle to jack the pulley into place, you'd never know. And (as it sounds like you found out) it won't necessarily affect the running of the engine like that. If the pulley slips, it will screw with the timing marks, but if it's timed correctly, you may never know. So if your PO did that and timed the engine when he put it together, it may have been like that (seemingly just fine) since then.

Cool. I switched over to a cable actuation a couple years ago and I've been considering doing the same thing Nice to see pics that prove it works! I like it! I should do that!

Numbers look good. Let's just hope that when the WOT contacts are back in the picture, it doesn't mess things up. Hopefully you'll be able to bend the WOT out of the way far enough so it doesn't interfere with your cruise numbers. I was thinking about it just a little more, and another relatively simple idea would be to mount a new WOT switch somewhere else on the system if you needed to. That way you could adjust where the WOT actuated independent of the idle switch. (or vice versa... install a separate idle switch, etc.)

I don't know what the original bolts looked like on the earlier cars, but I can confirm from tearing down a couple later cars, the bolts pictured above were used on the ZX motors. Don't know when they started, but I can confirm that's what they ended with. Flange heads and no separate washers.

Not a chance. We already talked about this.... I'm not getting pulled into a carbon fiber layup project.

Well, another idea... I have not looked into any of the details about the actual circuit that performs the WOT or idle enrichment. The rest of the ECU is a black box of analog voodoo magic, and there's no reason to believe the enrichment circuits are anything other than more of the same. And because of that, there exists the possibility the amount of enrichment may actually be able to be adjusted by controlling the amount of resistance between the contacts. In other words... The system normally works using two different resistance values - zero and infinite. Zero when the switch contacts are closed, and infinite at all other times. But what happens if you use a different value for when the switch is closed. Say 1K Ohms and infinite instead of zero and infinite? If you put a resistor in series with the WOT contacts maybe it will still actuate the WOT enrichment, but not by as much as when it sees 0 Ohms? You could try that at idle to see what happens. Compare what the A/F numbers do with 1) the WOT switch open, 2) switch closed, and 3) switch closed with some resistance in series. Just a thought if you wanted to give it a try.

Great input. Your findings with the WOT contacts are exactly what I meant with my #3 theory: 3) I think the WOT contacts close too early and the car runs too rich when they do. It's clear from studying the system that the WOT contacts close long before you are actually at WOT. And that's why I was theorizing they closed too soon. But when gas is cheap, emissions standards are loose, and you want to sell sporty cars, you would err on the side of burning some extra fuel instead of the opposite. So going up a hill on the highway closes the WOT contacts. So what? It's just a little more gas. Butterfly valves (like the throttle plate) are way way non-linear, so even though the plate isn't completely horizontal when the WOT contacts close, I was thinking that maybe you were pretty much there as far as max flow goes. But your A/F readings show that may not be the case. So what are the alternatives? First alternative I got is the simple one... "Do you really need it at all?" By that, I mean... Can you tune the rest of the system such that the idle looks good, cruise looks good, and WOT is rich enough even without ever closing the WOT contacts? If not, then the next alternative is what you already mentioned... Bend the WOT contacts as much as you can to delay the closing of the contacts. But as Blue mentioned, you can only do so much with that. Once the cam ramp is over, it's over. And bending beyond that will make it so the switch never closes at all. If there's still not enough adjustment there, you may want to play around with different cams. That part should be a breeze for someone with a 3-D printer to whip out. Small and not particularly accurate. You could make a custom cam with more rotation between idle and WOT.