wish i knew what it was but i don't.. i can tell you its a Holley 4bbl with vacuum secondary's i replaced the accelerator pump with one for a 4160 carb and it fit perfectly... there's only like 3 different part numbers for thoes so i know that wont narrow it down. the cars not with me right now but i will get numbers later. i have a few issues with it. but the back story, the car sat in a field for 17 years, (289) everything was rusted solid. nothing on the carb moved. i removed and cleaned what i knew i could put back on... which wasn't much. and i eased and lubricated the hell outa everything lest till they moved freely. the car will start and run ok. sometimes after it sits for over a day it takes 3 or 4 tries to get it fired up. is this normal? how many times do you pump the pedal on a cold start? or pump and hold?, ok then when its running. and warmed up.. say i take it for a short drive. the engine will start to rev up very high on its own and hold a high rpm idle.. somewhere between 2 and 3.5k rpms. (no tach) i have to blip the throttle really hard 2 or 3 times and it will settle back down for a bit. but then eventually do it again... whats causing this? ive checked for vacuum leaks and found none., next issue is the secondary's wont open... there is a chamber like thingy on the top right rear of the carb. black roundish plastic with 3 screws that im assuming is a vacuum thingy for the 2nds? all of the rods move ok, i can open them by hand when engine is off... could this vacuum thingy be bad like the accelerator pump? if so anyone have a good write up on how to replace it? i removed the 3 screws with no avail.. thinking it has another screw on the bottom? could buying another $100 4bbl new carb fix all of my issues? oh.. and pretty sure this carb is not stock with the engine, although its obviously at-least 17+years old. thanks all!!

 

I usually push the pedal 2-3 times then let off and my 65 i6 starts right up, first try. I was told you shouldn't hold the gas in when you start an engine, especially when cold as it can damage things.

As far as the engine revving up high after startup, that is the choke in action, warming up your engine. That is supposed to happen and if you tap the pedal like you did, it settles back down.

Sorry, this is all I know to contribute!

 

[QUOTE=65vertable;7640975]wish i knew what it was but i don't..
The "LIST" number on the front of the choke will tell us.

…the car will start and run ok. sometimes after it sits for over a day it takes 3 or 4 tries to get it fired up. is this normal?
Yeah. Especially if you don't set the choke.

how many times do you pump the pedal on a cold start?
2-3.

or pump and hold?
The choke does the "hold".

, ok then when its running. and warmed up.. say i take it for a short drive. the engine will start to rev up very high on its own and hold a high rpm idle.. somewhere between 2 and 3.5k rpms.
Choke idle is set too high.

(no tach) i have to blip the throttle really hard 2 or 3 times and it will settle back down for a bit. but then eventually do it again... whats causing this? ive checked for vacuum leaks and found none., next issue is the secondary's wont open... there is a chamber like thingy on the top right rear of the carb. black roundish plastic with 3 screws that im assuming is a vacuum thingy for the 2nds? all of the rods move ok, i can open them by hand when engine is off... could this vacuum thingy be bad like the accelerator pump? if so anyone have a good write up on how to replace it?
There is no way to check this by hand unless you have the engine on a chassis dyno.

i removed the 3 screws with no avail.. thinking it has another screw on the bottom? could buying another $100 4bbl new carb fix all of my issues? oh.. and pretty sure this carb is not stock with the engine…

No kidding. No 64-66 Mustang came with a Holley. The only Holley-equipped Mustangs were the 390GT, 428CJ, BOSS 302, BOSS 429, and 429SCJ.

 

taking apart a carb is easy as can be, just keep everything sorted, theres really not that many parts. take pictures to help you remember where to put stuff back. get a bucket of carb cleaner and let the metal parts sit in it overnight. take them out, put it back together using a rebuild kit (~20$) which comes with gaskets, needle, accelerator pump spring, etc.

set the fuel/air mixtures with the screws, set idle speed, set cold idle speed, profit

it would be VERY helpful to buy a shop manual you could buy them online (haynes manual) for 64.5-73 v8 mustangs. it shows you how to do everything you need to do.

 

how can i adjust the choke idle speed?? its getting very annoying,. the car will do ~40mph in 4th gear with no throttle added...

 

with the car on find the fast idle cam/screw this should be near the black cap you mentioned (if the carb is set right the choke should be closed) now there should be a screw behind the black piece that holds the fast idle cam in place, unscrew this a bit and your idle should lower, now bring it down to 1500-1700 rpms. now blip the throttle and it should go to warm idle, there should be a screw near the accelerator linkage, screw this in or out till you car runs smooth

 

ok i messed with the car today, got a pic of the carb AND the stupid list number, which is... 'LIST-1850-3-2417' so what is it? lol i also drove the car alot tonight. it seems like when i give it alot of gas is when it decides to idle at like 2.5-3k and stay there. i had to smash the throttle 3 or 4 times to up to 5k to get it to drop back down. i zip tied the choke open and i think it made it worse. and now the stupid things leaking gas all down the left side.... from up high... who knows... stupid carbs!!