Captain Obvious

So about that third center mount... I assume that the direction of "problem" you were originally having was fore/aft (as opposed to up and down), since the rod ends have adjustable height. I would HOPE (and assume) that the manifold manufacturer located and drilled all those holes on a machine capable of holding a suitable tolerance to use all three mounting points. You are threading a non-precision shaft into a (hopefully) precisely located hole, and then locking it in place with a non-precision nut which may or may not pull straight up on the shaft. I'm not surprised you can't get three of them in enough of a line to have the shaft rotate smoothly. How about a thin tapered washer under the center mount lock nut to cant the rod a little in the direction of your choosing? You could test the concept using by slipping a feeler gauge under the nut on one side and snugging up the nut. But before you do any of that... It looks like they did not machine the top surface of the mounting bosses? Make sure there isn't simply a thread burr kicked up or something that is preventing a perpendicular face. Me? I would have machined the tops of those mounting bosses normal to the threads. Just throwing out some ideas... Maybe something will stick?

How about modifying the threaded portion of the new 3/8 rod ends down to 5/16 instead? Drilling & retapping the manifold is hard to undo, and you could always buy another set of 3/8 rod ends. Lathe would make quick work of that. In a pinch without access to machine tools, you could probably even use a file to cut them down to size before running a 5/16-24 tap over them. How good is your eye? Nice pics of the linkage BTW.

I don't get any pics... Just this: I'm assuming there's a problem on my end?

Yup. There they are! Thanks Blue. I gotta assume from the lack of input that these aren't highly thought of?

Getting an accurate reading with those IR guns can be difficult. Not only the distance from the target, but the accuracy also depends a whole lot on the emissivity of the material being scanned. Shiny stuff like intake manifolds, aluminum head, or stainless headers can be trouble. You can read a bunch here about how to take more accurate measurements: Noncontact Infrared Temperature Measurement | Emissivity Measurement ? Raytek.com Emissivity of Materials | Thermal Emissivity*? Raytek.com

Nobody has ever seen anything like those before? Have I got a one-off custom here?

Was removal of the original fuel pump always part of adding A/C?

I don't remember where I found it, but I've got a chart that lists the part numbers for the ECU's from 75 through 83, and according to that chart, there was no distinction between California ECU's and the rest of the states until 1980. By that, I mean... in 1980 and later years, the ECU used for California was different than the ECU used elsewhere, but prior to 80, that's not the case. Note that it was not unusual for them to use different ECU's between auto and manual trans cars, and of course between turbo and non-turbo.

So any luck with a photo detailing just the linkage as it stands today?

Looks like a nice car, but I don't like it when people say stuff like this... Rug on the dashboard? Steering column clamshell off and sitting in the passenger seat? Aftermarket puffy armrest on the center console? and... Where are the flat-tops? 73 should have flat tops! For $12K? 100% original? I mean, I wish mine looked that nice, but... Original what?

I like that idea. That would remove the tangential component of the spring completely. Just like so many other throttle return springs. Mill some flats onto the actuator rod or drill a cross hole... Anything to get a grip on it. Attach some brackets to the rod to accept a hook on one end of the spring, and then hook the other end of the springs to the mounting points.

Here's another identify that wheel entry. What are these?

Haha! The "which is mine" part is a quote from the famous paleontologist, Anne Elk. IIRC, she did a lot of work with Brontosauruses. About the temp sensors... I did more, but figured that everyone here would gloss over and pass out so I didn't mention it. I wanted to determine what the temp sensor outputs would be at additional points, so I employed the Steinhart–Hart equation to model the thermistor outputs across the entire range. Using the data points in the factory service manuals, I now have a graph of the sensor outputs full range. It was during this process that the math highlighted some mistakes in the FI "bible" and the pre-78 factory service manuals: http://www.classiczcars.com/forums/fuel-injection-systems-s30/48782-water-temp-sensor-air-temp-sensor-resistance-charts-typos-manuals.html#post424758

Three mounting points on a shaft are often trouble. You have to do it right, or not do it at all. For those of us that aren't familiar with this system at all (like me)... Can you take a closer-upper pic of the linkage and it's mounts? Fill the long way of the frame with the linkage rod you currently have?

Great stuff. I wish I had seen that before I bought I bought the wrong engine... Might want to note that the later N47 heads are a little different than the earlier ones. I don't profess to know all of the changes, but one thing I can absolutely confirm is a threaded sensor hole into the water jacket back between spark plugs 5&6. And where does the W48 exhaust manifold fall in that progression?

The 58 Ohms makes perfect sense. Thats the resistance of the heating element in the thermotime. In fact, pretty much everything you have tested and posted makes sense with the exception of the grounding 45 thing, and the swapping the wires thing. One last thing before I throw in the towel and just revel in your success... Do the pins on your thermotime line up like the picture on EF-32 in the 78 manual?

Don't know if this is old news or not, but I've turned up a mistake in the pre-78 service manuals pertaining to the resistance readings from the air and water temperature sensors (Pages EF-52+53 for 1976 and Pages EF-53+54 for 1977). Similar mistakes are in the FI "Bible" as well. Apparently there was some difficulty translating from degreesC to degreesF. Add a language translation to that, as well as a positive to negative conversion complication, and you've got issues. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ To start, here's the 78 air temp sensor chart as a reference. The math works out as do the thermister resistances: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ But in the previous years, the temp vs resistance charts are wrong. Here's air temp: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ And here's the water temp sensor on the next page: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Similar mistakes in the Fuel Injection "Bible". Here's the air temp sensor test: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ And here's the water temp sensor test:

45 should be 12V to engine block when the key is in START and 0V to engine block at all other times. You should get these same readings regardless of whether the connector is clipped on the thermotime or not. And 46?... 46 is a little more complicated, but if you have the thermotime unplugged and the CSV connected, then you should see the exact same thing on 46 as you see on 45 - 12V at START and 0V at all other times. If you have both the thermotime and CSV unplugged at the same time, 46 should be always 0V regardless of key position. It makes no sense to me that it would work if you ground 45 and smoke if you ground 46... Are you sure you're not mirroring the numbers when you spin the connector around?

Haha! You must be in Marketing or Sales. :laugh: Seriously though... There's no way I would guarantee the performance of the ECU would be dead-nuts identical today as it was the day it left the plant almost forty years ago. No way. Things are better than vacuum tubes and oil filled paper caps, but we haven't figured out how to get all the long term drift out of everything yet.

Yeah, the vehicles voltage will mess with continuity and resistance measurements. You can not trust that tone to provide accurate results on anything that's powered. If you start adding voltage to a resistance or continuity measurement, seemingly unpredictable things can happen. So about that short to ground... Is this what made it work? Because I still can't explain it: Depending on the quality of the ignition switch and all the connectors between the battery and the thermotime connector, you may have gathered up enough resistance along the way such it wouldn't draw enough current to actually smoke, but there's no way putting a ground there as drawn should make the system work as intended. I'm an hour away....

Yeah, that mess is an indication of how well the anti-drainback feature is working. Here's a couple of my dissected filters. Old style AC Delco before they switched to the plastic filter support cage: (Notice the little split where the filter media was never connected properly at the factory.) Typical Purolator. Been this way for at least ten years:

And about that shorting to ground to get the CSV to spray with key in START... Is this where you connected to ground? Because if this is what you really did, then something should have smoked. If it didn't, I have no explanation other than someone has messed with the system somehow.

The CSV should be polarity and connection independent. I haven't taken one apart, but I expect it doesn't matter which connection goes to which prong. You could probably swap the two wires right there at the CSV and I don't think the system would care. The thermotime on the other hand is most definitely connection specific. I clipped the 1978 cold start stuff out of the wiring diagram and added a few notes: The connector pin on the tt which gets 12V on START should be 45 The connector pin on the tt which is connected to ground when the tt is cold should be 46. I'm not sure what you mean when you say "loss of ground at both 45 and 46". Without more specific measurement definitions... Are you measuring voltage, or resistance? The reason I ask is because you can measure 0V between two things, but that won't necessarily tell you if they are connected together or not.

Sounds like the CSV and the thermotime are both functional, but the rest of the stuff has me confused as well. I know you said it looks like all the original wiring, but maybe someone swapped something and then wrapped it back up again? Give me a little bit... I'm gonna make a picture.

Depends on the design of the oil passages and the position of the oil filter. I guess your truck likes the anti-drainback. On a different, but related note... I've had some filters that DO include that anti-drainback feature where the valve does not work. You can tell when you take the filter off the car that the inner portion has already drained out past the valve. It's not supposed to, but I've found that they sometimes do anyway. Maybe one in twenty?