DadAndLadZ

I thought so too but don’t have access to one. Just picked up a replacement temp sender today and will be installing it ASAP. Will report back!

It doesn't overheat until you drive it.

Yeah planning to replace the sender this week. Radiator is full but again I am unsure if there might be pockets of air lurking somewhere in there… Trying to avoid buying specialty tools like the burping funnel kit until we absolutely have to because our budget is tight but will if it looks like that’s the problem.

In neutral if I rev it up, the temp goes back down to normal, even after the gauge shows it going into the red. You can see this toward the end of the video.

Yeah I am gonna swap the sender unit out, I thought maybe there was air in there but not sure that would cause this particular behavior?

Hey all: We have our 260Z idling reasonably well now, and the temp gauge shows it staying right at normal operating temperature as long as we let it idle — but the second I shift into first gear and let the clutch out, the temp immediately climbs to 250°+. Here is a little video demonstrating the issue: We have some coolant system flush stuff in there right now and plan to drain it soon, as it’s been in there about three days now and we have run the engine a little each day. But before I put any more coolant in there I want to hear some ideas about what might be causing this. The car never acts like it is actively getting too hot, but the gauge says otherwise. Your two cents is much appreciated. Thanks! MC and the Boys

Thanks, I actually have an OG printed copy!

Howdy again, folks... Now that the bulk of our carburetor issues have been resolved (thanks to so many of you here in these forums!), the boys and I are messing around with some other issues on the car. I finally put a timing light on the engine and though I am pretty sure I can see the mark on the pulley, it looks like the little plate with teeth on it that indicates degrees of advance is missing. So it would help me if you would look at this short video and the link below to let me know if I a) do in fact need to buy a replacement, and b) have the right one. Is this the one? https://zcardepot.com/products/ignition-timing-indicator-tab-oem-240z-260z Thanks in advance, we really appreciate all y'all! Michael & the Boys Project Z ICT

Oh this is very useful! Thanks!

Thanks, that is very helpful!

I do have a timing light and we will be working on that coming up.

Well, we put the carbs back on today and did a rough dial-in and even managed to take Project Z out for a little sprint around the block. I have been thinking about what @Captain Obviouswrote the other day regarding where the distributor advance hose goes, and found some pix of SU carbs where the "nail hole" did indeed have a hose nipple on the exterior. I still have the advance hose hooked to the port right behind the carburetor in the manifold for now but I totally see what the Cap'n was talking about. Would something like this (image below) work, if I tapped the hole out a little to thread it in? Or is there a readymade part for this? Any advice on this is welcomed. Oh, and I put together a new video for our YouTube channel, too. This one was more fun than the last couple because it felt like we actually made a little progress! Thanks again, folks. Let me know what you think about that vacuum port biz above, if you have an opinion on it. Oh, and also on the overheating! Plz/thx. Best, MC in Wichita

Oh you guys will hear for sure! lol … THANKS most sincerely for your patient help!!!

Wow, good info, thanks! We will put it back together ASAP!

That’s the plan now… JFC I was losing my mind. I know I should have just taken the damn thing off earlier but it always feels like opening a can of worms to me. You would think I’d be used to it by now lol… It does have a vacuum advance hose going to the distributor, it’s just attached a little farther back, behind the spacer on the manifold. I guess it’s a by-product of mixing and matching parts off different years of car. Many thanks again to everyone who has chimed in on this, here’s hoping the boys and I can start working on something else soon! lol

Been too hot to work in the garage but we finally had a couple nice days and I think we may have solved the mystery… You’re gonna laugh.

They feel exactly the same when the car is off. They look the same, adjusted the same, filled with the same oil. But turn on the engine and the front piston opens three times wider than the back one. I intend to get some single weight oil too, but when it’s 100 degrees in the room I can’t imagine this stuff is too thick, and the back carb works fine. Freaking mystery 😕

Yeah right before I shot this video I put all my muscle on trying to force that tab while it was running but no dice. And it does this even with all the linkage completely unhooked from the carbs, there is nothing external that I can see putting any kind of load on there. Will just have to pop it off. Thansk again to everyone for your patience and kindness with me.

Just using some motor oil, I think it’s like 10W40. As far as I can tell it’s staying in there, I haven’t seen it leaking anywhere.

I just had both dashpots off, both the throttle plates appear to function identically except when the engine is turned on. I don’t know how to check that with engine running tho. I guess it’s time to pull it and see if anything reveals itself from the backside.

Here ya go, shoulda done that in the first place, sorry.

Still banging my head against the wall. It’s 105 out today and a pleasant 92 in the garage with the AC going so I give up for the day. Here is some action video for you to peruse should you choose to go down the path of madness with me… IMG_6405.MOV

Thanks for clarifying, I finally figured out the layout of those four screws, but not until after I had jacked them all up lol… I have owned numerous motorcycles with twin carbs, and had little trouble adjusting or even rebuilding them, but the only other car I ever had with them was my old ‘68 Mercedes 220, which had dual Solexes. Strangely they always worked perfectly and I never touched them once in the couple years I had the car. From everything I read, these SUs are an improvement over the original carbs that came on this car, and I am sure once I figure out what’s up here, they will serve us well. I truly appreciate the kindness and patience of you folks in this forum. It’s easy to be disheartened, but you are making me feel less stupid. lol

That was exactly my interpretation. What other linkage connects them, or what is the appropriate way to loosen said linkage?

Thanks, I had them off before but didn’t know that’s what I was looking for so didn’t take note. I am glad there is a way to check this without removing the carb altogether… This is the one real drawback to these sidedraft units…you can’t see down em! Much obliged.