Dadsun

The car has spent it's life in south Louisiana as far as I know. I bought it from the original owner last spring. I would bet, based on my experience digging into this car, that he had average Joe mechanic on this thing a lot. Very little Z car expertise in our part of the country. They had screwed up several things, including the wiring which caused the tach to stop working. Thankfully, this forum has helped me fix that and sort through this neglected car.

Well, it's all apart now, but I went and found an old picture. The orange line traces the 5/8" hose. The light blue circle is where the thermostat/sensor/pressure/valve/backflow preventor/whatever is. I am calling it a sensor because someone said it may be that. I don't know what exactly it's purpose is. It's all new to me. As for making a 2nd thread, sorry about that. My other thread is about the carb conversion, and this was specifically about this large hose that seems to complete the circle (in duplicate to the coolant intakes going through manifold) on that side of the engine bay. btw, that 5/8" hose was actually blocked because the brass elbow (can't see it well in the picture, but it's just below the blue circle) was completely clogged.

Are you answering me with my own quote? lol... that's a bit offsides. 😄 In the other thread, I was specifically asking about that sensor/valve and its removal. But, the more I look at it, and see diagrams people have posted here of the round top coolant flow diagram, it seems the 5/8" hose is not necessary either. I was not sure if it was there to carry a higher volume of hot water around to the heater coil for climate control.

I'm in Louisiana. I would think if I were in Canada the coolant (heating) lines going through the manifold would be more important. This other topic has several folks voting to keep the lines flowing, however, due to keeping temps from getting too uneven in spots.

I'm converting my '73 240z's flat top carbs to round top SU carbs. In the process, I'm sorting out, restoring/replacing coolant lines. I found this topic while investigating whether or not to delete the manifold coolant pass-through. But, my flat tops had some other stuff I'm trying to remove if not needed. See this pic from that thread, with my mark-ups added in PURPLE and GREEN to show flat top elements I'd like to remove. The green sensor is in the 2nd pic here: QUESTION: Can I just get rid of this 5/8" hose and sensor altogether for round tops? That would only leave the coolant flowing through the intake manifold on that side of the engine compartment.

Ok. So I can take it out. Btw, Do people sometimes just cap off the intake coolant lines on the round top setups? Talked to a guy in a Datsun shop in Georgia who said it's common. As for now, I plan to run the coolant through the intake manifold.

I went ahead, since my header was rusty and fugly, and shipped it off to Jet-Hot in OKC. Two week turnaround. $225 plus one way shipping. In the meantime, I'm going through hoses and coolant lines. See pics. What is this inline valve in the coolant line near the break booster (where it connects to a hose that runs around under air filter housing to thermostat)?

@siteunseen - thanks. I have no background knowledge here, so it's good to hear that. I have thought about taking the headers off (they are the standard 3-2-1, which are stock headers, as far as I know) and sending them to get Jet Hot coated instead of wrapping. But, that's like $400. I just figured if some see it as a problem then now is the time to address it. But, if the braintrust on this forum think no wrap or coating is necessary, then that's good to know. I have an electric fuel pump back just off the gas tank.

I found the free hanging vapor flow valve hose that goes to #5. See pic. It is in the blue zip tie. Thanks. Sigh, so many hoses to replace. The other hose within the blue zip tie goes to the crankcase and it looks like the big port there is where my PCV hose from carb linkage is, according to diagram I found, supposed to connect? It is currently not connected to anything. The flat tops setup I inherited had the PCV hose going straight to the air cleaner housing. Also, I've been reading about wrapping my headers, since they'll be exposed, and some even wrap the heat shield to prevent percolating in the carbs. Any thoughts on this?

An update... I've acquired the choke cable clamps, and removed the EGR housing at the top of the manifold. I am trying to sort out the differences in the flat tops hookups and round tops. Q1: Are there any other connections I should be expecting besides the 8 noted above (plus 2 choke cables and the 1 throttle arm)? [Edit: I also found the small distributor vacuum capsule line hookup] Q2: Coolant lines: It looks like the flat tops had four (4) coolant line connections and the round tops just the two (2) noted above, so I will need to cap/swap out a couple of connectors coming off the coolant lines to the new carbs. Any tips or links to parts that you've needed? See pics of the 4 current connections: Q3: Two (2) EGR wires run off into a bundle and I'm looking for the relay. I'm assuming I can just snip them and wrap them off instead of removing the relay? Q4: See air filter housing back. I know that #1 and #2 are the lines to float vents. And #3 connects to the hose to top of valve cover. What are #4 and #5? #4 looks like it takes my breather housing rubber plug (currently sitting on #3). Thanks for any help!

The original owner provided the original radio, which I'm installing now, but the slide switch for the antenna is missing. See yellow circled area in pic. I may have some old parts for swap, depending on what you're looking for.

I'd like to move to a round top fuel rail at some point. Sounds like it's not on the critical path at the moment, but would be ideal. I've already taken off my flat top rails once and re-wrapped them with new heat shield foil wrap when I was restoring the gas tank and cleaning all of the fuel lines. I didn't realize the old dilapidated wrap was asbestos. Ugh. I've texted the Paltech guy to see if he has choke cable brackets. They were not in the box. 😞

Thanks, guys. I believe, as an aside, I could also do away with the ugly heat wrap on the fuel rail now that I'm going to the round tops with the heat shield, carb/manifold spacers blocks, etc? I've seen posts about going to piano wire for the choke cables, but for now I'm going to keep these and keep applying cable lubricant. Seems to be helping.

I bought this Z (1973 240z, white/red, build date 10/1972) in April from the original owner, and have been working on restoring. (Will post some interior pics soon, hopefully.) As some of you know, like @Captain Obvious and others, the original flat tops were neglected and this car has been driven about 5K at most, in the last 20+ years. So, after some input from the board, and looking around, I settled on the Paltech round top SU carbs. They are beautiful. In fact, I'll have to clean/polish/replace the rest of the engine compartment elements to keep them from looking crappy by comparison. I an not a mechanic, but consider myself handy. I need some help on where to start. See pics. Q1: I know where several of these Paltech hookups map to on my ''73, but not all of them. Q2: I'm assuming the whole EGR crap can go away now - i.e., the wiring, coming from the distributor to the EGR mechanisms. Any tricks/concerns in the process? Q3: I've read on the forum that certain '72 models have water ports on the mounting between the carbs and the manifold. I have not taken mine off yet, but I'm assuming it will be obvious. Q4: Any other gotches, must-do's, don't forgets greatly appreciated!

I talked to the original owner today. He said he saw the old original antenna in his warehouse and will go see if the old up/down switch is with it. He is wondering if the guy who swapped out his original radio for a Casio tape player (blech) kept the old switch, and/or swapped in this newer 280z (?) switch.

That's what's confusing. That free hanging switch in the picture mounts vertically into the faceplate of a 240z radio, but just not my radio. I bought this car from the original owner 6 months ago and he says this is the original radio. If so, yes, I'm just missing the antenna horizontal sliding switch. I will take off the faceplate and look, but I don't think the radio chassis will accommodate a spot for that big vertical switch.

So, I'm still redoing my interior and hooking up the original radio. See pic. I've figured out the wiring for the radio, but it's missing the slide switch. But! There is this old toggle switch under the dash and it looks like according to some googling that it fits an even earlier model 240z. So, I'm confused. Looking for a slide switch that inserts into that radio slot in upper right. But also wondering why this other antenna switch is in my car. Build date was 10/72. Any help appreciated. Thanks.

View Advert WTB: 70-72 240z Stock air filter housing I'm swapping my '73 240z to the round top SU carbs, and need to swap out my air filter housing as well. Looking to buy the one as pictured. Advertiser Dadsun Date 06/04/2020 Price Category Parts Wanted Year 1972 Model 240z  

Another note is that the 15-30 second cold cranking process seems to have gone away. I suspect the vapor system leaks were causing the fuel to slowly drain from the rails and lines that run into the carbs, but not sure.

Gas restore completed and ran much better today! Onward to suspension, and then my paltech round top carbs, pertronix ignition upgrade, interior restore, etc. Side note: the electric fuel pump runs all of the time; not just at cranking. Anyone wired this to only run at startup? I thought about adding a switch that lets me cut it off after starting. It's noticably loud through the floor of the hatch area.

Thanks. That seems to have helped. And I fired her up. Stuck float makes sense. It's been sitting for about 2.5 weeks with the fuel rails detached.

HELP! So, I finished the tank restore and reinstallation. Replaced fuel hoses everywhere except the hard lines, which I cleaned out as best I could. And even took off the fuel rail and cleaned. It's all back on and no leaks except now.... I've got gas pouring out of the front carb's air intake on the air filter housing. See pic. Everywhere else is bone dry. I have not fired it up yet, thankfully. Just testing for leaks with the electric fuel pump pushing.

Turns out I have a great local source for the larger braided fuel hoses. Just under an hour away there is a heavy duty parts and machine shop in Natchez, MS, called Kaiser's. They do a lot of big tractor work, so they have big spools of hydraulic and fuel rated rated hoses. If you have a place near you that does similar work, check them out. I got the two larger vent hoses (5/8" and 3/4") there.

Thanks. I may pick up one or two of those from Banzai, but some of the prices are just absurd. I can't stomach paying $80 for a choke cable grommet, for instance. Or $80 each for strut tower caps.