4 barrel roch. carb question

[cutlassguy]

i was on the highway today when all of a sudden my car started running like crap so i pulled over and realized the electric choke was staying closed. after pissing around with it for 10 minutes in the freezing cold i ended up stuffing a piece of kleenex against the "high idle cam?" or that little ear type wieght looking thing behind the choke, so the butterfly would stay open and i could get home. so far i checked the choke wire with a multimter and the key on and theres a solid 12.4 volts there. watched a couple vauge youtube vids on choke pull offs and tested mine by making a mark on it and starting the car to see if it moves a little, seeing that it didnt i removed it and replaced it with another one from another 4 barrel roch. carb i had sitting here. basically the video said it should only move a little when the motor starts but mine has enough vaccum to suck the diaphram right in which pulls the lever to the secondaries all the way. is this normal? also if you know what the other diaphram towards the back does that would probaly help me out also. thanx!

 

[bill]

i was on the highway today when all of a sudden my car started running like crap so i pulled over and realized the electric choke was staying closed. after pissing around with it for 10 minutes in the freezing cold i ended up stuffing a piece of kleenex against the "high idle cam?" or that little ear type wieght looking thing behind the choke, so the butterfly would stay open and i could get home. so far i checked the choke wire with a multimter and the key on and theres a solid 12.4 volts there. watched a couple vauge youtube vids on choke pull offs and tested mine by making a mark on it and starting the car to see if it moves a little, seeing that it didnt i removed it and replaced it with another one from another 4 barrel roch. carb i had sitting here. basically the video said it should only move a little when the motor starts but mine has enough vaccum to suck the diaphram right in which pulls the lever to the secondaries all the way. is this normal? also if you know what the other diaphram towards the back does that would probaly help me out also. thanx!

Vacuum chokes are pulled in both directions, and if you have a lack of vacuum on one diapham or the other, the choke will either stay closed or not close enough. Sounds like your choke pull off isnt working properly. Check to make sure that the hose going to it isnt cut or cracked. once the engine warms up a bit, the choke should open slightly..and fully after the engine is near the normal temp range. Reving the engine usually helps to pull the choke off "full on" .. once the engine has started to warm a bit, 30- 45 secs max.

 

[cutlassguy]

what do you mean by vaccum choke? sorry if im misunderstanding but its an electric choke. i replaced the choke pull off tonight because the one on my car wasnt working and i happened to have a spare one that holds vacumm good. after watching another vid about it a guy was saying one of the worst things you can do is run a quad carb without a pull off or to have one that doesnt hold the secondaries back tight enough so im assuming its working right, and tomorrow im gonna check out the second diaphram at the back of the carb to see if its working or not. the problem now is it runs good but is stuck in high idle and wont kick down unless i poke that little ear tab down with my finger. i can kick it a hundreds times tho and it wont idle down...any ideas?

 

[bill]

what do you mean by vaccum choke? sorry if im misunderstanding but its an electric choke. i replaced the choke pull off tonight because the one on my car wasnt working and i happened to have a spare one that holds vacumm good. after watching another vid about it a guy was saying one of the worst things you can do is run a quad carb without a pull off or to have one that doesnt hold the secondaries back tight enough so im assuming its working right, and tomorrow im gonna check out the second diaphram at the back of the carb to see if its working or not. the problem now is it runs good but is stuck in high idle and wont kick down unless i poke that little ear tab down with my finger. i can kick it a hundreds times tho and it wont idle down...any ideas?

The choke is electric, but the linkage to control it has vacuum diaphrams that control it. It sounds like the linkage is sticking or that the electric choke is calling for choke when it shouldnt. The wire that runs to the choke energizes it and with proper voltage, the choke should open. pull the wire to the choke...see if it has voltage...http://www.thecarburetorshop.com/Automaticchokes.htm

 

[Bonnewagon]

There is an adjustment on the choke pull-off, it's that philips head screw/spring arrangement . When you replaced it you should have verified that the choke pull-off opening was the same. The gap is usually between 1/8'-1/4". And you replaced the choke coil so that should have been adjusted so the choke flap is totally closed when the motor is cold. So the sequence is like this: cold motor, tap gas pedal once, choke closes, fast idle is set (another adjustable item). Motor starts: choke pull-off opens choke specified amount for cold operation, motor runs fast (1500-2000 rpm). As motor warms up: choke opens completely, fast idle falls off (counterweight thingie) by tapping gas pedal, motor idles at specified curb idle speed. When the motor starts if the choke pull-off is correct it will run fine. If it dies, too much air, close up pull-off slightly. If it chokes, too much fuel, open pull-off slightly. To verify electric choke operation, with motor off, but key in "run", choke should slowly open completely. "Usually" the rear mounted pull-off is plumbed to a temperature/vacuum switch so the choke opens more in warm weather.

 

[cutlassguy]

i checked with a multimeter and theres 12 volts at the choke wire with the key on. today when i started it cold i tapped the gas and watched the BF close all the way, started it and it opened almost a 1/4 inch and stalled, so i restarted it and held it almost closed with my finger for about 20 secs then let it go and it went back to the same 1/4 opening and ran rough until it warmed up but still wouldnt kick down until i went in there and poked the ear tab down with my finger and stuffed kleenex in it again to hold it down. any time i would hit the gas a little that tab comes right back up and it goes back into high idle. ive already chucked the old pull off but when i compared them it looked exactly like the old one. if i start the car now it'll do the exact same thing so should the first thing i do be to back off the pull off screw? also i never replaced the choke coil, should i take it off and plug it in with the key on and see if the spring unravels? could that bi-metal spring have broke possibly?

 

[pontiacgp]

I think it sounds like the spring in the electric choke is the problem

 

[Phoenyx]

One of the reasons I like manual chokes better. 8)

 

[cutlassguy]

i agree pheonix, im almost ready to start taking all that crap off and just wire it open and deal with it i took the choke spring out before and it wasnt broken or anything but i guess i can check it out again. is there anything else that can be wrong with it? i installed it by putting it in and turning it until the spring closed the BF's so im assuming that was done properly. thanx guys! what should the first thing i do be?

 

[cutlassguy]

also it has a little tab that keeps it in one place once its seated all the way in so i cant turn it to adjust it unless i grind that little tab off.