Carburetor Conundrum (260Z)

[KenFirch]

Awesome videos with your kids!   Gearheads in training.  👍

[DadAndLadZ]

On 7/3/2022 at 9:12 PM, Captain Obvious said:

Your original carbs (the flat tops) had integral return springs built into them.  ... 

Can you take some decent resolution pics of your carbs and post them here for scrutiny?

I will take some close-up pix tomorrow and post here. Thanks, stay tuned!

 

[DadAndLadZ]

On 7/3/2022 at 10:17 PM, KenFirch said:

Awesome videos with your kids!   Gearheads in training.  👍

Thanks! The older of the two wants to be an engineer, and he wasn't around all the years I was driving old cars, so this is for his benefit!

[dutchzcarguy]

Hi DadandladZ,  I'm surprised that no one told you, you can download the service manual for your car here on the site.. 

Only now you have the round top carbs you have to download the 240z (and the 260z for the rest of the car/inlet manifold?)  serv.manual.

In there you can find the procedure how to set these carbs in the right way.

I have'nt read it all but i think you have the wrong inlet manifold and stuff on your car.. also look for leaks because that causes high rev's as you probably already know... good luck!

[siteunseen]

This was my "ah ha" read that helped me wrap my head around twin SUs one day.

The fuel level in the float chambers is most definitely #1, then getting the front 3 cylinders to run off the front carb "equally shitty" as the back 3 was #2. It'll run on 3 but barely. Don't forget about the vacuum advance nipple on the front carb. It needs to be hooked up to the dizzy or capped off if you're getting pull from somewhere else.

Thanks again to @240260280...

You doing good I know. Probably playing with grandkids? Anyway we miss you but life is more important than these old cars. 

 

Edited July 6, 2022 by siteunseen

[DadAndLadZ]

15 hours ago, dutchzcarguy said:

Hi DadandladZ,  I'm surprised that no one told you, you can download the service manual for your car here on the site.. 

 

Hey, thanks! I have a Haynes manual and a Z-Car restoration manual too but this thing has been Frankensteined and none of the pictures match what I have on the actual car! lol

[DadAndLadZ]

48 minutes ago, siteunseen said:

This was my "ah ha" read that helped me wrap my head around twin SUs one day.

 

Hey, thanks! Will check this out for sure. We have been busy over the long weekend, one of the great-grandparents passed away right on the Fourth of July and it's been family stuff the whole time. Will get back out to the garage to tinker some more soon — but with tomorrow's forecast calling for 104º F, it might be another couple days or so.

[DadAndLadZ]

OK, thanks for your patience, folks...here are finally some pix of my carbs as they are. If you see any red flags, I'd sure like to hear from you.

Short story for reference: Car runs. Front carb sucks vastly more air into the horn than back carb, even when throttle screw backed completely out and all linkages disconnected. Idles at 1500-2500 rpm at present, with all screws backed completely off the stops so carbs should be at maximum closed position. Cannot even remotely try to balance.

 

[siteunseen]

What does this go to?

And I would unhook the throttle cables while trying to figure it out.

 

[DadAndLadZ]

2 minutes ago, siteunseen said:

What does this go to?

And I would unhook the throttle cables while trying to figure it out.

 

 

Those are the choke cables, no? I have had the throttle linkage disconnected entirely while doing all this but have not messed with the cables indicated here. Still it makes sense to disconnect them in case it's a choke problem hassling me here, thanks for pointing it out. 

Also that fat hose goes from the valve cover to the back of the air cleaner assembly, as do the two smaller hoses coming from the carbs. The big one I assume is some sort of PCV thing? Here I reassembled the air cleaner backplate hose layout for a visual aid.

[w3wilkes]

Curious how the fuel lines go to a "T" and then over the top of the valve cover to... what? How about a pic of the other end of the single fuel line that goes over the top of the valve cover. I'm guessing it just goes to the hard line on the right inner fender? I'm also guessing you have an electric fuel pump at the tank? Or is there a mechanical pump on the passenger side of the engine?

[SteveJ]

11 minutes ago, w3wilkes said:

Curious how the fuel lines go to a "T" and then over the top of the valve cover to... what? How about a pic of the other end of the single fuel line that goes over the top of the valve cover. I'm guessing it just goes to the hard line on the right inner fender? I'm also guessing you have an electric fuel pump at the tank? Or is there a mechanical pump on the passenger side of the engine?

That's a good observation, @w3wilkes. @DadAndLadZ, you should probably check your fuel pressure. With not having the stock fuel rail, you lack the fuel pressure regulation afforded by the orifice in the return line.