Carb Question? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

OldSkool71 · 11-14-2003, 04:33 PM

Do you know if there is any way to adjust the choke on a stock set up? It is a Quadrajunk on the stock manifold with that spring thing for the choke. Every time I start the truck I pump it once and it usual starts but immediately starts to flood or something like it's too much choke on I have to try and keep the rpm's up to keep it from completly dying. And it take a minute or two before I can let off and then it seems like the choke is in the right position for it to run right? What do you think? I would like to get a new intake and carb, but I have to hold off for a few cuz I just dropped the cash ordering my 4/6 drop from ECE. Thanks for the help.

Ron

jorgensensc · 11-14-2003, 05:22 PM

Does it high idle wen you first start it up cold??

OldSkool71 · 11-14-2003, 05:24 PM

no it doesn't have a high idle. It just starts but I have to immediately get the idle up or it starts running rough like it is flooding or choke is on too much. And you can see the smoke coming out of the tailpipe, like choking or too much gas or something.

jorgensensc · 11-14-2003, 05:36 PM

I am no carb expert, but I know that mine high idles when it is cold, then I have to tap the gas after the truck warms up. Mine is a new edelbrock 1406 600 carb with electric choke. It sounds like your truck wants to supply fuel for high idleing when cold, that's why when you idle high yourself with your foot it runs until the truck warms up. Does this make any sense?? Hope This helped a little.

oldsub86 · 11-14-2003, 05:46 PM

Don't know what model carb you have but my 86 Suburban had a choke pulloff thing on the side of the carb. When that died, it acted like that. The choke needs to open a little as soon as the engine starts. The choke pulloff doodad opens the choke just a little as soon as the motor starts.

zyggy72 · 11-14-2003, 05:49 PM

It sounds as if the high idle cam is not engaging when you pump the gas pedal. How far down are you pressing the gas pedal when you first start it? It should only take at most 2 full pumps of the pedal to start it and have it on a high idle.
Hope my input helps

tom hand · 11-14-2003, 05:57 PM

If you get a book on q-jets there tons of adjustments and most of them involve measuring and bending the rods...Those chokes were not real great when they were new...GM had stopped using them by 75....went to a hot air setup, which sucked almost as bad, before they went electric. If you get a manual for a q-jet and go thru every setting you can get them to work pretty good but it takes patience...or you can go to a parts store and buy a $10 manual choke kit.

71-longbed · 11-14-2003, 07:53 PM

how exactly do you hook a manual choke setup to a divorced (manifold spring) choke ..doe sit connect directly to the fast idle cam and simple push it down .... just curious

my chocke work fine ..but i make some short trips sometimes ... and it doesnt get a chance to warm up ... and for some reason ..when i blip the throttle it doesn't disengage either ... so i just pop the hood and push the fast idle cam down a couple notchs so she does diesel when i try to shut her off

this is my experiance

walker · 11-14-2003, 08:07 PM

Lots 'o ways to adjust a choke. need to be more specific on what type of carb, what type of choke(elec, divorced,hot air,etc). The easiest thing to do is watch the operation of the choke and see what part is not moving like it should, choke pull off, high idle cam, choke butterfly. Sometimes all it takes is a little carb and choke cleaner to get things moving again. Of course that never happens on my cars, they always need a total rebild.

86SILVERADO · 11-14-2003, 08:59 PM

Before you start it up in the A.M look at the choke. It should be wide open. Get in and blip the throttle and get out and look at the choke and make sure it is now closed. It sounds like it is either open too far or closing completely. It needs to be open about 1/8 of an inch after you blip the throttle. If it is where it should be then you need to adjust the idle up some. Use the screw that has the spring around the outside of it on the opposite side of the carb from the choke. Pretty sure this should take care of you although I am no carb adjustment expert either. As mentioned before it could just be the linkage is sticking. You should always try the carb cleaner trick first. I usually use carb cleaner to get all the gunk out of there first and then hose it down with WD4O while working the fast idle cam up and down.
Good luck and I have (had) a 72 with the quadrajet and spring controlled choke. Still have the carb if you need a pic.

OldSkool71 · 11-14-2003, 09:09 PM

Yeah, I did the carb cleaner thing already, believe me it needed it anyway. Im not a carb expert eithier that's why im calling out to you who are. Would a shop manual help me out at all with the carb/choke stuff as far as adjustment and trouble shooting?

86SILVERADO · 11-14-2003, 09:18 PM

Old Skool I will post a pic for you. I don't have the carb from the 72 handy right now but I have anotherone that is pretty close. Just hang on a few.

86SILVERADO · 11-14-2003, 10:04 PM

Oldskool

Just clean the areas of the two circles very well, like in the picture clean, you know what I mean? and you should be all set. The top circle you need to get behind the choke pull off bracket where the shaft goes into the carb.

OldSkool71 · 11-14-2003, 10:43 PM

Do I need to take the carb off to do that or can I leave it on?

11-14-2003, 04:33 PM	#1
OldSkool71 C/10 CLUB MEMBER Join Date: Jul 2003 Location: Lakewood, CA Posts: 993	Carb Question? Do you know if there is any way to adjust the choke on a stock set up? It is a Quadrajunk on the stock manifold with that spring thing for the choke. Every time I start the truck I pump it once and it usual starts but immediately starts to flood or something like it's too much choke on I have to try and keep the rpm's up to keep it from completly dying. And it take a minute or two before I can let off and then it seems like the choke is in the right position for it to run right? What do you think? I would like to get a new intake and carb, but I have to hold off for a few cuz I just dropped the cash ordering my 4/6 drop from ECE. Thanks for the help. Ron __________________ -Ron-

11-14-2003, 05:22 PM	#2
jorgensensc Registered User Join Date: Jul 2003 Location: Cypress, Tx Posts: 4,005	Does it high idle wen you first start it up cold?? __________________ 1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE

11-14-2003, 05:24 PM	#3
OldSkool71 C/10 CLUB MEMBER Join Date: Jul 2003 Location: Lakewood, CA Posts: 993	no it doesn't have a high idle. It just starts but I have to immediately get the idle up or it starts running rough like it is flooding or choke is on too much. And you can see the smoke coming out of the tailpipe, like choking or too much gas or something. __________________ -Ron-

11-14-2003, 05:36 PM	#4
jorgensensc Registered User Join Date: Jul 2003 Location: Cypress, Tx Posts: 4,005	I am no carb expert, but I know that mine high idles when it is cold, then I have to tap the gas after the truck warms up. Mine is a new edelbrock 1406 600 carb with electric choke. It sounds like your truck wants to supply fuel for high idleing when cold, that's why when you idle high yourself with your foot it runs until the truck warms up. Does this make any sense?? Hope This helped a little. __________________ 1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE

11-14-2003, 05:46 PM	#5
oldsub86 Registered User Join Date: Dec 2002 Location: Canada Posts: 695	Don't know what model carb you have but my 86 Suburban had a choke pulloff thing on the side of the carb. When that died, it acted like that. The choke needs to open a little as soon as the engine starts. The choke pulloff doodad opens the choke just a little as soon as the motor starts. __________________ 1968 Chevy - 292 with a powerglide

11-14-2003, 05:49 PM	#6
zyggy72 Can't kick the addiction! Join Date: Jan 2002 Location: Riverton, CT 06065 Posts: 402	It sounds as if the high idle cam is not engaging when you pump the gas pedal. How far down are you pressing the gas pedal when you first start it? It should only take at most 2 full pumps of the pedal to start it and have it on a high idle. Hope my input helps

11-14-2003, 05:57 PM	#7
tom hand CCRider Join Date: Feb 2000 Location: Olive Branch,MS,USA Posts: 2,232	If you get a book on q-jets there tons of adjustments and most of them involve measuring and bending the rods...Those chokes were not real great when they were new...GM had stopped using them by 75....went to a hot air setup, which sucked almost as bad, before they went electric. If you get a manual for a q-jet and go thru every setting you can get them to work pretty good but it takes patience...or you can go to a parts store and buy a $10 manual choke kit. __________________ 72 GMC Sierra SWB almost finished---- 84 Softail Olive Branch MS

11-14-2003, 07:53 PM	#8
71-longbed Its Magically Delicious Join Date: Jan 2003 Location: oregon Posts: 2,398	how exactly do you hook a manual choke setup to a divorced (manifold spring) choke ..doe sit connect directly to the fast idle cam and simple push it down .... just curious my chocke work fine ..but i make some short trips sometimes ... and it doesnt get a chance to warm up ... and for some reason ..when i blip the throttle it doesn't disengage either ... so i just pop the hood and push the fast idle cam down a couple notchs so she does diesel when i try to shut her off this is my experiance __________________ 71 C10 LWB 350sbc -TH350 12 bolt 3.42 Posi Of all my favorite things to do, The utmost is to have a brew. My love grows for my foamy friend, with each thirst-quenching elbow bend. Beer so frosty, smooth, and cold it's paradise pure liquid gold. Yes beer means many things to me that's all for now cus I gotta pee.

11-14-2003, 08:07 PM	#9
walker Registered User Join Date: Jul 2003 Location: north of Phx AZ about 30 miles Posts: 698	Lots 'o ways to adjust a choke. need to be more specific on what type of carb, what type of choke(elec, divorced,hot air,etc). The easiest thing to do is watch the operation of the choke and see what part is not moving like it should, choke pull off, high idle cam, choke butterfly. Sometimes all it takes is a little carb and choke cleaner to get things moving again. Of course that never happens on my cars, they always need a total rebild. __________________ Andy,Phx AZ '67 C-10 (Ahhh, done at last. Well there is that disk front end I want to put in and...) "23 C-Cab-sold '48 Ford 8N tractor(still working) '67 Scout(Now on the road) '70 MG B.-sold

11-14-2003, 08:59 PM	#10
86SILVERADO Registered User Join Date: Dec 2002 Location: Hills of Western Mass Posts: 626	Before you start it up in the A.M look at the choke. It should be wide open. Get in and blip the throttle and get out and look at the choke and make sure it is now closed. It sounds like it is either open too far or closing completely. It needs to be open about 1/8 of an inch after you blip the throttle. If it is where it should be then you need to adjust the idle up some. Use the screw that has the spring around the outside of it on the opposite side of the carb from the choke. Pretty sure this should take care of you although I am no carb adjustment expert either. As mentioned before it could just be the linkage is sticking. You should always try the carb cleaner trick first. I usually use carb cleaner to get all the gunk out of there first and then hose it down with WD4O while working the fast idle cam up and down. Good luck and I have (had) a 72 with the quadrajet and spring controlled choke. Still have the carb if you need a pic. __________________ 86 Silverado C10 back to 305 power! 67 C30 Dually Dump, with 350 transplant, Rockhauler 05 Duramax 3500 "If at first you don't succeed, try a bigger hammer" Member of the 1-Ton club!

11-14-2003, 09:09 PM	#11
OldSkool71 C/10 CLUB MEMBER Join Date: Jul 2003 Location: Lakewood, CA Posts: 993	Yeah, I did the carb cleaner thing already, believe me it needed it anyway. Im not a carb expert eithier that's why im calling out to you who are. Would a shop manual help me out at all with the carb/choke stuff as far as adjustment and trouble shooting? __________________ -Ron-

11-14-2003, 09:18 PM	#12
86SILVERADO Registered User Join Date: Dec 2002 Location: Hills of Western Mass Posts: 626	Old Skool I will post a pic for you. I don't have the carb from the 72 handy right now but I have anotherone that is pretty close. Just hang on a few. __________________ 86 Silverado C10 back to 305 power! 67 C30 Dually Dump, with 350 transplant, Rockhauler 05 Duramax 3500 "If at first you don't succeed, try a bigger hammer" Member of the 1-Ton club!

11-14-2003, 10:04 PM	#13
86SILVERADO Registered User Join Date: Dec 2002 Location: Hills of Western Mass Posts: 626	Oldskool Just clean the areas of the two circles very well, like in the picture clean, you know what I mean? and you should be all set. The top circle you need to get behind the choke pull off bracket where the shaft goes into the carb. Attached Images

11-14-2003, 10:43 PM	#14
OldSkool71 C/10 CLUB MEMBER Join Date: Jul 2003 Location: Lakewood, CA Posts: 993	Do I need to take the carb off to do that or can I leave it on? __________________ -Ron-

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