720 z24 Carburetor

[LRAYVICK]

Back in 07 rworkman98 was good enough to post this link to a blowup of the 720 carb http://www.geocities.com/rworkman98@sbcglobal.net/carb.htm. The rod on Part #46 is broken on my carb. Does anyone know what that part does?

 

I am still having a problem with my idle when cold on my 86 2.4 L. It idles very slow when cold and will die if I gas it then let off. After it warms up it idles fine.

 

I am looking at the vacuum hose diagram. Is there a hose I can plug or re-route to fix this my variable idle? I am thinking I will clamp the thermal vacuum valve and the vacuum control valve so I have straight vacuum to the distributor.

[datzenmike]

Looks like the choke unloader.

 

On cold days when the choke is on and working and you down shift into second to accelerate on the on ramp or to pass someone, the choke will hinder performance. At heavy throttle and RPMs, vacuum is used to pull on that lever and hold the choke open. When the throttle is released the choke goes back on.

 

Very likely you can run without it and never know.

 

 

When cold is the choke this...

http://i138.photobucket.com/albums/q251/datzenmike/720%20stuff/carb720shouldlooklikethisLarge.jpg[/img]"]

 

 

...or this

http://i138.photobucket.com/albums/q251/datzenmike/720%20stuff/carb720notlikethisLarge.jpg[/img]"]

Edited July 31, 2009 by datzenmike

[LRAYVICK]

Thanks Mike. Since it almost never gets cold in my part of So Cal I won't worry about it.

 

The idle problem I mentioned has been fixed more or less by bypassing the thermal vacuum valve and the vacuum control valve so I have straight vacuum to the distributor. It is still a bit of a hard starter and when the motor is fully warmed up it idles a bit too high. I guess after I change what may be 23 year old plugs and adjust the valves probably for the first time in its life it should do better.