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Project THESEUS: A '74 260z

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Coming together very nicely Noll, I appreciate the true amount of work that has gone into the build, and that you're building it to be driven. The first twisty road will be nirvana!

I have fallen behind in my build due to work, so have been watching your progress and enjoying!

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23 hours ago, Lockleaf said:

If you end up with vibrating, youtube channel halfass kustoms has a video on using your car to align the ends before tacking together.  His builds are pretty great.


Good to know, many thanks! Hopefully I don't need to chop it apart again but I guess we'll see.


11 hours ago, EDM620 said:

Coming together very nicely Noll, I appreciate the true amount of work that has gone into the build, and that you're building it to be driven. The first twisty road will be nirvana!

I have fallen behind in my build due to work, so have been watching your progress and enjoying!


Thanks! Even as the person who has done the work, it's easy to look track of just how much has gone into the build/restore sometimes. It sure will, getting closer and closer to that point every day hopefully.





Not much picture-worthy today; installed a bunch of rubber plugs and seals (firewall, hatch, etc), ran the hood latch cable, speedometer cable (that one was a pain), and choke cables, and got the horns bolted on and radiator roughly in place. Need to get some proper-length bolts and rubber isolators for it tomorrow.


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More misc. today. Coil cleaned and in, and plug wires in too. Properly mounted the radiator as well, using fuel hose as spacers so it's not hard-mounted.


Fuel filter added before the electric pump:


And all fuel plumbing done up front too:


Upper and lower rad hoses in too, as well as the inspection light.


Heater hoses too:


Most of the throttle linkage in as well. Need to get an e-clip for the pivot, and wait for the paint to dry on the main rod to the intake (not going on until I build the exhaust though):


Also got a ton more under the dash all hooked up, flasher/blinker relays, engine bay wiring harness plugs, etc etc. Only things that I can see that are still unplugged are the connectors to the center sub-harness (radio, console switches/lights etc), and one unidentified 6-pin connector I'm currently looking through the wiring diagram to figure out.

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More done today, some frustrations too though.

Started by extending the wires to the transistor ignition unit so I could put it somewhere that actually made sense:




The voltage regulator was rattling, so pulled it apart to reveal a blown cap. I have a probable lead on a replacement regulator, although the cap might just be to smooth things out a bit for all I know.


The shunt for the ammeter was in rather bad shape, although the internals looked good so I cleaned it up and threw it in the car for now (more on this in a sec).





Horns all wired up:


Hooked the alternator up too, although I had to weld a bolt on the end of a terminal that had snapped off halfway down before I could attache the connections properly:


Batt tray in, and fusible link box in place:


And hooked up a battery with some cables I found. Initially had two positive ends so had to use the vise grips for a good connection for the neg. cable. Initially I messed up and had the + cable on the wrong side of the starter solenoid, so it immediately started cranking when I connected the cable to the battery. I had made sure the car was in neutral just-in-case before though, so no harm done and the engine sounds healthy when cranking which is good.


This is where the frustration starts. After hooking the + to the correct side of the starter solenoid (as well as the main harness positive and the starter trigger wire), there is nothing whatsoever in any key position.

I did some sleuthing with a multi-meter, and while the rear (larger, blue in the below pic) circuit has power, the other smaller one that does, well, everything, has no voltage at all. Both fusible links tested good for continuity, so I know that's not the issue.

As far as I can see, the only place the WR wire (red circuit) can get power from is inside the shunt itself (makes sense, that's how the ammeter compares the draw to the direct-from-starter circuit), so the culprit must either be the shunt or the wire from it to the fusible link (I have yet to check both for continuity, that's next on the list.

If the shunt is bad, it looks like I can just splice together the two circuits at the spot circled in blue and unplug the other 2 wires and I should have power to everything but no working ammeter (no biggie).  If anyone thinks that this isn't the case or that the blue circuit (WR wire, front smaller fusible link) gets from somewhere I'm not seeing, I'm all ears.

Oh, and to add to the annoyance, I unplugged the voltage regulator while the battery was connected (to check for voltage there) and the rear (larger, blue circuit in my diagram) started smoking. Not entirely sure how disconnecting the regulator resulted in that; the car was not running so it's not like the alternator would be overcharging suddenly?
I unplugged the battery, checked the affected fusible link for continuity (read 3 ohms, so fine), plugged the voltage regulator back in, and then the battery.

This resulted in the fusible link melting in half. Really confused as to why - if unplugging the voltage regulator caused a short etc, then why did it continue to melt after stuff was restored to how it was??? Continuity in the link was still good etc after the first smoke. Just annoying as Now I'm not sure if the voltage regulator being unplugged was the culprit and I really don't know what made it happen if not. Oh, and finding a replacement fusible link around here might be a pain.


Full-size image here: https://live.staticflickr.com/65535/51394839470_60185b7cbe_o.jpg

Anyway, called it there for the night. Might do some troubleshooting as to what caused the fusible link issue tomorrow, or just leave it till the week when I can (hopefully) get a new one and work on the exhaust.

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Posted (edited)

Had another go at the short issue after a good night's sleep, and got it sorted out. Unplugged the remaining fusible link (so the rest of the car's wiring wasn't a factor), and started checking every part of everything - starting at the starter, working through the larger fusible link connection, to the shunt, onwards to the other fusible link connection etc.

Found the culprit after eliminating everything else as an issue - the terminal on the alternator that charges the battery is a direct short to ground, zero ohms to the chassis. Might be able to pull it all apart and fix/replace the insulator that's likely the issue, but for 60CAD/45USD (plus core charge, but I obviously have a core) it seems a no-brainer to get a reman alt and not deal with the unknowns (plus this car sat outside for a very long time before I got it and I have no idea how old the alt is anyway).

Right-side terminal in this pic:


And snapped another pic of the car while I was climbing up to get some parts out of storage.


At this point the remaining electrical work should just be the alternator/fusible link, finish making the headlight relay harness, and connect up all the switches in the center console (and the console itself). The latter two don't really need to happen for the car to be able to start up though, will do them later.

So, alt/link, make sure there are no further electrical issues, make exhaust, put some gas in the tank, and go for first start!

Edited by Noll
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Posted (edited)

True enough haha, but I need to weld a v-band connector on the header and don't want to take it off twice so will at least be doing that first.





Got a 50a fuse from Napa to get the wiring back up and running while waiting on a new fusible link (if I can find one that is). the link was rated at 80A so this will be perfectly safe in the meantime.


Next order of business, get the center console in so I could plug in the hazard switch as a lot of stuff runs through it. Seems i have a 240z center console, had to modify the front mount for the dash to sit in the right spot to bolt up:


Will need to trim the bottom of the heater control surround slightly, which is why it's slightly awry here. Interior is coming together nicely though!


The result - pretty much everything seems to work! horn, turn signals, hazards, blower motor, wiper motor, washer motor, etc etc.

The things that currently don't are all dash backlights, the map light, and the starter won't kick on. I initially thought there was an issue with the electric fuel pump too, but some looking at the wiring diagram shows it only ever kicks on when there's enough voltage from the alternator - safety cutoff for accidents etc. I'll run it direct to a battery for priming before first start then reconnect properly.

Oh, and the right-side turn signal indicator bulb is not working (turn signal itself is fine); will pull the gauge and replace it eventually I guess.




Spent a bunch more time pouring over the wiring diagram, and got the interlock wiring all sorted out. my car is missing the emergency switch and interlock relay, but i can bypass whatever's left by just connecting two wires in the emergency switch plug.




Will do some troubleshooting on the backlight issue, but that's also not needed to get the car running initially. Exhaust needs to happen next then make sure all the vacuum lines are hooked up and try to fire.

Edited by Noll
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9 hours ago, Noll said:

True enough haha, but I need to weld a v-band connector on the header and don't want to take it off twice so will at least be doing that first.





Got a 50a fuse from Napa to get the wiring back up and running while waiting on a new fusible link (if I can find one that is). the link was rated at 80A so this will be perfectly safe in the meantime.



You should be able to get fusible link wire and make up your own fusible links. Any good auto parts store should carry it.

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On 8/24/2021 at 10:10 AM, Racer X 69 said:

You should be able to get fusible link wire and make up your own fusible links. Any good auto parts store should carry it.


That's the hope! my local Napa is having a look for me, if they can't get it for some reason I'll inquire at some other places too.




Got the gauges working - dome light fuse replaced and voila. Always nice when it's simple.


Got the car to crank over with the key too now with the interlock bypassed. Took a little while but the oil eventually got up to the head after the oil pump caught prime, so all is well. Great spark too, so just need to prime the fuel system.

Took the header off and welded on a v-band flange, then put it back on the car and properly bolted it and the intake up fully. Got the vacuum lines sorted too, damper oil in the carbs, and hooked up the throttle linkage, so that side of things should be good to go.



Got a bit carried away here and ended up building the entire exhaust. I am exhausted (no pun intended), but hey, it's done! Pretty happy with it for my first go at making an exhaust and what I had to work with, it hugs the transmission tunnel and underside pretty well considering. Re-used the old resonator as it was still in good shape and no point spending more money for no reason.


Will get it back on the car tomorrow probably, then just need to do fuel prime and I can get it started (hopefully).

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Figured I've put enough stuff together to throw the front strut bar on. It looks great on the car but doesn't quite fit for some reason.



Also realizing that the bar section that extends out about as far as the strut nut will probably be a hood clearance issue, I can cut the top half off and plate it without much hassle though.

And the culprit, it hits the valve cover for some reason. I really don't know why given that the strut tops are higher than stock (thanks to the camber plates) and it previously attached to the 3 strut holes, but oh well. It's an issue and I'll fix it.



The solution is probably just going to be to chop the bottom half out of the two cross-tubes like this then plate over it with stick-gauge steel to maintain strength. Won't be hard to do and I still have some of the paint I used left over to touch-up with.



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Posted (edited)
6 hours ago, grannyknot said:

Get that puppy on the road, do you think you'll be able to make it down to Zfest this coming Sunday?


That's the goal! I'd like to, but I think I'll likely miss it this year unfortunately, definitely won't be there in the Z and in general I don't think I can justify the cost of gas/accommodation right this sec given how much I've been dumping into the Z in this final push to get it on the road. next time for sure though.




Got the Z fired up (mostly) for the first time! It stumbled for a bit (it sat for probably 20 years, so fair enough), idled nicely for a few more seconds, and then backfired out the rear carb (as far as I can tell from the video anyway) and for unknown reasons revved to the moon before I shut it off.

Not sure of exactly why (throttle linkage didn't seem to be stuck from what I can see in the video, no vacuum leaks that I can think of, etc), but will figure it out then fire it back up after priming the fuel system properly - was just running of what I put in the float bowls there.



if anyone has any suggestions as to what could have caused the runaway I'm all ears - I'd say the backfire pushed the throttle blade open but the linkage wasn't stuck so I don't see how that would have caused anything more the a blip in the throttle.


EDIT:  pretty sure it must have just been it running out of gas in the bowls and going way lean, you can hear it starting to creep up just before the backfire and big rev. Throttle linkage is smooth as silk so can't be that.

Edited by Noll
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Was planning on doing a bunch of stuff today, but ended up spending hours dealing with the fuel system as every single compression fitting was leaking to some degree for unknown reasons. Fun times. Got it sorted now, but that ate most of the day.

With that done, made a coolant overflow bottle/mount. It's a bit extra, but a fun touch IMO and cost me nothing. Will be refining the bracket/cleaning it up then painting and adding foam padding.


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Got the Z back on the ground today. Sitting rather low, I like the look but will need to do some testing to make sure it won't hit on anything (tires to fender lips up front under hard compression is probably the most likely culprit).



Clearance: exactly one sideways 2x4.


Turns out I miscalculated with the exhaust when building it on wednesday - in my defense I was very tired and it was dark lol. Will do some chopping (likely near red lines), and get it raised up properly. Flex pipe gives me wiggle room with the front section.


Did a bunch more misc. work today too - coolant added (will need to add more as it runs and pushes the air out of course), lower seatbelt stuff bolted in, seats bolted up properly, defrost ducts plumbed, wiring cleaned up under dash, and put down some 3M grip tape where my feet will go. Would have been better if it was black, but it will be functional - without carpet the floor would probably get pretty slick when wet.

Other than finding the glovebox (put it somewhere for storage and can't remember where), interior stuff should be good to go from the backs of the seats forward.


I then went to start on the headlight relay harness and promptly dropped and shattered one of my nice Bosch H4s (not from high up either, just bad luck). Fuck. Thankfully i still had one of the lights that was on the car when I got it (housing rusted to nothing), so I removed the broken lens, and replaced with the one from that housing. Waiting for the sealant/glue to dry at the moment. Won't look exactly the same as the other one of course, but will work as it should and you'd have to look at both pretty closely to tell I hope.



Edited by Noll
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Adhesive/sealant all dry, and pretty happy with the result of the headlight repair:


And made the relay harness. It looks deceptively simple here but took a couple hours to make; laying out all the wires where they should go, lots and lost of soldering, adding plugs, making the sub-harnesses from the buckets, etc. Nothing overly complicated, just a lot of time spent to make it be built right.


And on the car. Can't really see much difference here, but that's kinda the point after all, fits/blends in nicely.


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Been pushing forward with a lot of kinda boring but necessary stuff.

New alternator and belt in. Had to file the mount ears a bit as they were too thick to fit over the stock lower mount for some reason (new casting? idk). only had to take a tiny bit off though. Plugged the alt back in and yay, no dead short when the battery is hooked up.


Hatch latch/lock all in and working (and locking with key!)


designed/printed some covers for the factory unused holes near the throttle rod (RHD heater box maybe?), and put the re-plated metal cover over them.


Took the current throttle linkage return spring brackets off, will be making some that are a lot nicer and about 10mm longer to keep more tension on the linkage.


Re-routed the carb vent lines, as without the stock airbox they just would dump onto the hot exhaust. Turned out decently clean IMO, teed them together and ran a line over to the pass. side so if they do dump fuel it shouldn't be somewhere where it'll combust.



Getting there! lots more misc to do as well as bigger stuff such as precisely setting camber/rideheight/toe, making sure the engine runs nicely, clutch/brake bleeding, etc.

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On 9/2/2021 at 7:47 PM, slowlearner said:

So great to see the car so near driving! 


BTW, I'm not sure if this is an issue on Zs, but my dual SU linkage is very prone to hanging up at idle. Apparently they're famous for it.


Indeed, I can't wait till it moves under its own power!

it is a common thing on Zs too to my knowledge, happily I have mine as smooth as butter and moving/returning flawlessly. Added stronger return springs than stock, and put graphite lubricant on every pivot point.




Still working on the misc. stuff - interior assembly, small engine work, etc etc. Some of the highlights include:

welded some scrap into a cupholder:



Decided where I wanted to drill holes for the side mirrors and got them mounted:


And reworked the rear section of the exhaust so it wasn't like 1/4" off the ground. This was a bit of a pain to do in-situe (removed the rear section to cut/section/weld but left the front 3/4 of the exhaust bolted up), but got it done.



And after. The car is rather low so there's obviously never going to be tons of clearance but way happier compared to before.


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On 9/1/2021 at 8:48 PM, Noll said:

designed/printed some covers for the factory unused holes near the throttle rod (RHD heater box maybe?), and put the re-plated metal cover over them.



Those holes are for the air conditioning lines to pass through the firewall.

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On 9/6/2021 at 4:55 PM, grannyknot said:

Love the coffee holder!  I'm going to make one for my Z thanks.


11 hours ago, slowlearner said:


Yeah, I've been meaning to do the same. 


Thanks! The one I made is nothing fancy, but should work pretty well.


10 hours ago, Racer X 69 said:

Those holes are for the air conditioning lines to pass through the firewall.

Ah, that makes sense!






Got the suspension mostly set up today - didn't do toe yet, but each corner's ride height and camber. The old accident damage definitely was rearing it's head here, the adjustment required side-to-side in the rear was quite different. Got the camber within 1/3 of a degree though, so well within in factory tolerances. Will probably eventually get T3 or Apex adjustable LCAs to be able to play around with more stuff.

Rolled it outside and grabbed some pics.



The volvo really shows off how small it is:


I tried to bleed the clutch too but had zero luck getting any pedal at all from a gravity bleed. Apparently there is a one-way valve in the master cyl that could be stuck and letting fluid bypass? I might just buy a new MC as it's like 30 bucks and I think mine is the original 48-year old OEM one.

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On to one of the last welding jobs on the Z. I may have a lead on a pair of better doors, but in the event that doesn't pan out I want to have already started on fixing these ones.

Started by welding up all the old mirror mount holes in the driver's door:



Cut some strips off my 2nd hacked-up hood to use to fix the door bottoms:


Today's goal was to make up the exterior skin panels, shape them to the rockers and tack them on in place - I'll butt weld them in properly then pull the doors off to do all the structural repairs etc.





Both door skins aren't really attached at the leading edge which is why they're bowing out in the pics. I assure you that the gaps are actually even haha.

Need to decide just how proper I want to do the repairs, would like to get better doors eventually so might just do the bare minimum to make them not have holes etc. We'll see.

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Continued on with door repair today. Got all the panels that I had made welded on properly and cleaned up. The new sections are bit wavy (the p/s especially) as they're just a single layer of metal at the moment, once the doors are off the car I'll obviously be welding a flange on the back and connecting them to the bottom face of the doors etc.




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Been madly trying to get everything done, so haven't posted much.

Some highlights of recent work include:

Notched the strut tower bar only to/ find that when I reinstalled it it suddenly had more clearance than before, like it should? Idk what the cause was, but hey, not a bad thing.


All painted and on the car:


Replaced the clutch master and got the clutch bled (all seems well with the clutch as far as I can tell, feels decent). Replaced the booster too as the pedal was locked solid pretty much and I narrowed it down to the booster - not sure of the cause, but got a brand new reman booster from a friend for 50CAD so can't complain. Wasn't too bad to swap it out even with the dash etc in there now.


Got the whole front end properly on (well mostly, bumper/grille will be later). Lot of tweaking to get stuff to sit right, but I'm happy with it for now - panel gaps aren't amazing but acceptable, just need to adjust the inspection panel lids a bit more and should be good to go. I even got the hood latch aligned perfectly the first try which was pretty nice.



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