Captain Obvious

They make specific "glass buffing" stuff... Cerium oxide. I've not looked into the specifics, but I assume it's harder than what they use in paint compounds.

Before you scrape it, I would try some solvents. Acetone, Methanol. Maybe some paint remover? Might get lucky and find something that will just wipe it off?

I can already tell you that the lash on most of your valves is too tight. The back side (non-lobe side) of the lobes should never be clean like that. That's a sign that the valves are never completely closing and the base circle is rubbing all the way around. And valves that never close can make some strange noises sometimes. I can hope that it's as simple as that?

This is hanging on my toolbox for a task I've been meaning to get to:

pogden, Sounds like great progress. And to add a little more detail to what Steve mentioned above... The Volt warning lamp does more than just light up when there's an issue. It also supplies "bootstrap" current to the alternator system to get it up and working properly when you first start the car. As you found out, you should use an incandescent bulb in that application or things might not work right. Obviously.

Yeah, I'd be happy to help if it weren't at the opposite corner of the state. Upper left corner is about seven or eight hours away from the lower right. I agree on the purpose of those plastic plugs... Back in the old days, they would drill holes, stick a wand in to spray rust preventative goop inside and then plug the holes with caps like that. The most well known company was "Ziebart". I can't believe they went right through the VIN tag though. "My boss says I need to put the holes one foot apart. So I put the holes one foot apart. That's my job."

Just trying to do my part. For solidarity, I got lucky too. Did a happy dance:

There's no way I would reuse that bolt. I would chuck up the remains of the bolt in the lathe and drill a hole in the end. Do the same thing to the threaded stump, and then turn a metal dowel pin to fit the holes. Press the dowel pin into place to align the two while you run a small weld bead around where it broke. If your welding skills are good, they say "the weld is stronger than the base metal".

Or.... My next thought is that maybe there's something wrong with your AFM. Hahaha!!! Yeah. me either. Glad you got it working. And all the other work you did will only help moving forward. So were the numbers on the rebuilt AFM correct? Was it the "right" AFM for the year and all?

Interesting... Pretty much everything sounds like it's working OK, but the engine is starving for fuel once you get above idle. So to answer some questions: Yes, it is possible for the EGR to be stuck open even if there's no vacuum applied. But that would cause an issue across all operation conditions, especially idle. If the EGR is stuck wide open, I doubt you'd be able to get a steady idle at all. Same for the PCV if it were stuck open. Sounds like a classic fuel capacity issue, but your fuel pressure up at the rail is OK. Maybe your fuel injectors are partially clogged? They can pass enough fuel at idle (because the engine just doesn't need that much fuel at idle), but when you're taxing them to pass more fuel than that, they can't. There are little screen filter cups on the inlets to the fuel injectors. Maybe they are partially plugged with crud? Maybe the injectors themselves are plugged, or sticky, or both? I'm not sure your conclusions are valid. You're running a tiny bit rich at idle (12.7 - 13.0) which is fine, but just because you can sometimes nurse it up to 3500 doesn't mean you've really got the flow capacity. An engine with no load will "run" with an extremely lean mixture. What's the A/F ratio when you manage to nurse it to 3500? To me, it sounds like you're a little rich at idle, and as the RPM's go up, you get a little leaner, and a little leaner, and a little leaner, until it's finally so lean that it just won't run at all.

I've got one of those too. Not nearly as clean, but works fine. Honestly though, my current go-to is my "old" Harbor Freight trickle charger. It's pretty much a constant current source limited to about 1/2 Amp up to about 12.5 Volts, and then drops the current off above that. By the time you get to 14V it'll give the battery whatever it'll take (which is usually in the milliamp range). At one point, I burned it up. Not sure how, but I let the smoke out. So I figured (since they're disposable) that I would just buy a replacement at HF. Well unfortunately, it turns out that they changed the design... The "old" one still has a step-down transformer in the wall-wart, but the "new" one is a semi-conductor switcher like the other new junk. Hated it. (Men On Film). I mean, don't get me wrong... it's all cheap Chinese junk. But the older junk is better than the newer junk. They took most of the copper out and replaced it with Silicon. So in the end, I reverse engineered my "old" HF charger and fixed it. Anyone surprised? Here's the old one all fixed and also sporting a potentiometer mod to adjust the output voltage: And here's the new one. Flyback switcher with opto-coupler feedback loop. Don't like it at all:

What the old chargers did with a lot of copper and iron (in the form of a transformer), the new ones do with semiconductors. And in today's age, silicon is a lot cheaper than copper. So the bottom line is that most of the new chargers now have silicon components where the old transformers used to be. The way of the world. Lightweight silicon and software instead of heavy copper and capacitors.

So we've known eachother for how many years... And you're just figuring that out? Na-Nu Na-Nu.

I think that since everything is essentially dead ended (or at least should be), there's enough vacuum for everybody. Why don't you "T" a vacuum gauge into the line and drive around like that a little. You'll get a feel for where the vacuum peaks. And if it peaks somewhere other than light cruise, you might need to come up with some sort of alternative. I believe the ignition advance tops out somewhere around 15-20 in Hg. I don't know anything about the big bore TB. Other than it's got a big bore.

I think that the shape of the hole(s) are also as important as the sizes. For example, if I theorize way above my pay grade, I would imagine the shape of the distributor advance goes like this... They wanted a very narrow spike of vacuum oat a specific pedal position, so they used a narrow slit. And I can affirm (from driving around with a vacuum gauge T'd into that line) that the vacuum spike is very narrow and very high (vacuum). The EGR ports on the other hand, appear to be placed to provide vacuum over a much broader pedal position. I'm guessing the smaller hole in the back is used to "extend" the EGR vacuum value deeper into the throttle. So my read on the whole thing is... They optimized the ignition advance to kick in only at one narrow pedal position (light cruise), but the EGR is activated over a broader range and deeper into the pedal (medium cruise). But, neither of those ports will produce any significant vacuum once you get above medium cruise.

As Site mentioned above, the original throttle body has two ported vacuum sources. One for the EGR and the other shared by both the carbon can and the distributor vacuum. Here's another pic showing the two vacuum nipples: And about the idea of sharing the same ported source for all three things (distributor, EGR, and vacuum can), it'll "work", but you can tell from the placement and size of the original vacuum holes that Datsun wanted different vacuum profiles for the two different ports. Here's a pic down inside the throat of the original throttle body. The three small holes in the back are for the ported vacuum sources. (The two larger holes in the foreground are for the BCDD). The narrow slit hole on the left is for the distributor and CARB can. And the pair of holes on the right are for the EGR. You can see by looking at the shape, size, and position of the holes, that they will have different vacuum profiles at different pedal positions. Looks like this: So I'm thinking that it'll "work", but the vacuum profiles won't be the same as stock. Then again... Who's to say that your one ported vacuum source is the same as either stock port anyway?

Awesome! Oh... And don't drive. Your dog is so gonna love you when you wake up in the middle of the night with the hot pepper and tequila sweats.

Not sure where you got your numbers, but they are different than what I get when I go directly to the source(s): AR is 24.5 cents per gallon: https://www.dfa.arkansas.gov/images/uploads/exciseTaxOffice/2020MotorFuelsTaxRateAnnouncement.pdf SC is 24 cents per gallon, but will be going up to 26 cents/gal at the beginning of July: https://dor.sc.gov/tax/motor-fuel And yes, while PA is higher, I'm seeing 57.6 cents per gallon: https://www.revenue.pa.gov/GeneralTaxInformation/Tax Rates/Pages/MFT Rates.aspx There is apparently talk in PA about eliminating or reducing the tax: https://www.governor.pa.gov/newsroom/governor-wolf-commits-to-phasing-out-gas-tax-announces-commission-to-develop-funding-solutions/ And I'm not sure what the numbers mean, but here's what I find for CA. I'm not sure if that's 2.25% + .005 + .505 per gallon or what. But here's the chart: https://www.cdtfa.ca.gov/taxes-and-fees/sales-tax-rates-for-fuels.htm They aren't making any more dinosaurs ever again so it's not like it's going to last forever.

Like Site, I'm still a Ramen guy. The Gospel of the Flying Spaghetti Monster says that eating Ramen and dried pastas allows the struggling college student to afford more beer. And since beer is the drink of Pirates (the chosen people), it suggests that the FSM is trying to turn college students back into Pirates. You all been wondering what I'm the Captain of (besides the obvious)? I like beer and I've been known to say "Aaaaargh!" And "Mate... Fetch my brown pants!"

The 260/280 steering column is different than the previous years, but I don't know if they moved the mounting points as part of the changes.

Of course you do. What's not to like? From https://www.spaghettimonster.org/about/ "Religious texts tell us that humans evolved from Pirates. Consider that so-called “science experts” would have us believe humans evolved from primates, pointing towards the shared 99% shared DNA between humans and primates. But humans and Pirates share upwards of 99.9% of DNA. We believe that Pirates were the original Pastafarians and that they were peaceful explorers. It was only due to Christian misinformation that they have an image of outcast criminals today. No one knows what the afterlife really holds, but we are told FSM Heaven has a Beer Volcano and Stripper Factory." A beer volcano and stripper factory? Sign me up!! Can I get a "Ramen?"

I don't know if it's been mentioned, but those /\/\/\/\/\/\ markings probably signify "resistor".

Another opinion? "Ewwwwww!"

Deleted everything I had here before because it was wrong. Here's a pic from ebay with a pair of those in pretty good shape. I think this is what they looked like at one time. Not sure if they changed the color of the rubbery nugget over the years though.

Well as I said, I'm not sure how much difference a quarter turn would make, but just wanted to mention it. As for calibration... Here's a pic of some testing I ran some time ago. Ballpark should operate something like this: