2 questions - The 1947 - Present Chevrolet & GMC Truck Message Board Network

BB72CHEVKT · 08-31-2007, 10:10 AM

In the photo with the zip tie that I am trying to use to keep choke off is it
affecting the secondaries from opening. I think that rod golden rod opens the secondaries. The other photo is for someone to show me how/where I adjust the idle. It needs to come up just a tad. It will run all day in park but at a stop light with the truck in drive and my foot on the brake it will sometimes try to die as well. Thanks

ckhd · 08-31-2007, 11:52 AM

Sounds like you have carb issues. Maybe you should think of getting it fixed instead of trying to band-aid it.

First, yes, the zip tie is interfering with your secondaries. That vacuum thing doesn't open the secondaries, it keeps them closed. Tying it in that position is tying your secondaries closed.

Second, in the second pic, close to where it says "Quadrajet" should be a screw that will adjust idle. However, there are two screws in the front that adjust the idle circuit (In the second pic, you can see it on the front of the carb at the bottom - gold colored screw). Those need to be adjusted first.

ckhd · 08-31-2007, 11:56 AM

By the way, I notice you are missing your choke rod. If you are having choke issues, get a choke rod, and a new choke coil and fix it right. The old design may be simple, but just ask my '72 burb, and it will tell you that simple works just fine.

BB72CHEVKT · 08-31-2007, 12:53 PM

The carb was just rebuilt by SMI (sean Murphy Induction in CA. The carb works fine. I do not have a proper choke set up. I have the choke rod but the thermostat spring it is connected to is too tired to work properly. It is not an issue in TX not to have a choke this time of year. I can move the zip tie to fix choke. Which direct do I need to turn them and do I need to adjust both?

ckhd · 08-31-2007, 01:06 PM

The one screw that is near the "quadrajet" should be backed clear off so it isn't 'pushing the pedal' at all. Then, back off both of the screws on the bottom, this will make the idle circuit run rich. Then, one at a time, slowly screw them in until the rpms at idle drops slightly, then back them back out 1/2 turn. After that, if your rpms are still too low, use the screw near the "quadrajet" to raise the idle rpms. I think the proper idle speed for an automagic is something like 800rpm. You might have a tune-up sticker somewhere that will tell you for sure.

Texas or not, I'd still replace the spring. Not only will it close the choke when it's cold, but it will open the choke when it's not and eliminate the need to zip tie anything.

68gmsee · 08-31-2007, 10:29 PM

BB72, I don't use my choke in the summer for my 69 chev with 350 and it starts fine also. My 6 cylinder GMC, however, balks a little if I don't choke it slightly when starting cold from sitting overnight. Once it's warmed up and during the day, I don't need it.

Mind you, this is during the summer only. Come winter time, you might want the choke on yours. Here's a sight that sells them. Check it out. My 69 is on the blink right now so I'm going to wait to buy one for it.

http://www.brotherstrucks.com/prodin...number=CS41B00

08-31-2007, 10:10 AM	#1
BB72CHEVKT Junior Member Join Date: Mar 2007 Location: Hideaway, TX Posts: 4,950	2 questions In the photo with the zip tie that I am trying to use to keep choke off is it affecting the secondaries from opening. I think that rod golden rod opens the secondaries. The other photo is for someone to show me how/where I adjust the idle. It needs to come up just a tad. It will run all day in park but at a stop light with the truck in drive and my foot on the brake it will sometimes try to die as well. Thanks __________________ 71 Suburban 350/700R4 Project Trixie 72 CHEVY,Highlander,SWB,396,T400 Last edited by BB72CHEVKT; 09-03-2009 at 03:42 PM.

08-31-2007, 11:52 AM	#2
ckhd Registered User Join Date: Oct 2000 Location: St. Johns, Arizona Posts: 2,660	Re: 2 questions Sounds like you have carb issues. Maybe you should think of getting it fixed instead of trying to band-aid it. First, yes, the zip tie is interfering with your secondaries. That vacuum thing doesn't open the secondaries, it keeps them closed. Tying it in that position is tying your secondaries closed. Second, in the second pic, close to where it says "Quadrajet" should be a screw that will adjust idle. However, there are two screws in the front that adjust the idle circuit (In the second pic, you can see it on the front of the carb at the bottom - gold colored screw). Those need to be adjusted first. __________________ my 2¢ - t.i.o.l.i. Bowen 1968 K20 fleet 1969 K10 swb fleet 1972 K10 Suburban 1972 C10 lwb step 1992 K1500 'burb 1995 K2500 'burb 1997 C1500 'burb 1999 K1500 2000 K1500 'burb Why do I own so many Suburbans?

08-31-2007, 11:56 AM	#3
ckhd Registered User Join Date: Oct 2000 Location: St. Johns, Arizona Posts: 2,660	Re: 2 questions By the way, I notice you are missing your choke rod. If you are having choke issues, get a choke rod, and a new choke coil and fix it right. The old design may be simple, but just ask my '72 burb, and it will tell you that simple works just fine. __________________ my 2¢ - t.i.o.l.i. Bowen 1968 K20 fleet 1969 K10 swb fleet 1972 K10 Suburban 1972 C10 lwb step 1992 K1500 'burb 1995 K2500 'burb 1997 C1500 'burb 1999 K1500 2000 K1500 'burb Why do I own so many Suburbans?

08-31-2007, 12:53 PM	#4
BB72CHEVKT Junior Member Join Date: Mar 2007 Location: Hideaway, TX Posts: 4,950	Re: 2 questions The carb was just rebuilt by SMI (sean Murphy Induction in CA. The carb works fine. I do not have a proper choke set up. I have the choke rod but the thermostat spring it is connected to is too tired to work properly. It is not an issue in TX not to have a choke this time of year. I can move the zip tie to fix choke. Which direct do I need to turn them and do I need to adjust both? __________________ 71 Suburban 350/700R4 Project Trixie 72 CHEVY,Highlander,SWB,396,T400

08-31-2007, 01:06 PM	#5
ckhd Registered User Join Date: Oct 2000 Location: St. Johns, Arizona Posts: 2,660	Re: 2 questions The one screw that is near the "quadrajet" should be backed clear off so it isn't 'pushing the pedal' at all. Then, back off both of the screws on the bottom, this will make the idle circuit run rich. Then, one at a time, slowly screw them in until the rpms at idle drops slightly, then back them back out 1/2 turn. After that, if your rpms are still too low, use the screw near the "quadrajet" to raise the idle rpms. I think the proper idle speed for an automagic is something like 800rpm. You might have a tune-up sticker somewhere that will tell you for sure. Texas or not, I'd still replace the spring. Not only will it close the choke when it's cold, but it will open the choke when it's not and eliminate the need to zip tie anything. __________________ my 2¢ - t.i.o.l.i. Bowen 1968 K20 fleet 1969 K10 swb fleet 1972 K10 Suburban 1972 C10 lwb step 1992 K1500 'burb 1995 K2500 'burb 1997 C1500 'burb 1999 K1500 2000 K1500 'burb Why do I own so many Suburbans? Last edited by ckhd; 08-31-2007 at 01:07 PM.

08-31-2007, 10:29 PM	#6
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: 2 questions BB72, I don't use my choke in the summer for my 69 chev with 350 and it starts fine also. My 6 cylinder GMC, however, balks a little if I don't choke it slightly when starting cold from sitting overnight. Once it's warmed up and during the day, I don't need it. Mind you, this is during the summer only. Come winter time, you might want the choke on yours. Here's a sight that sells them. Check it out. My 69 is on the blink right now so I'm going to wait to buy one for it. http://www.brotherstrucks.com/prodin...number=CS41B00



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.