I had an earlier topic about springs for my Carter BBD. I did get a variety of throttle return springs and set everything up. Fortunately, I got it all started up and running without problems. It was idling still high (it was cold start) so I 'blipped' the throttle to get it lower, but my pedal stuck down. I pulled it back into it's original spot, but the carb was now idling higher than it was! I had to gently persuade the high idle cam down into a spot where it should be and pulled the excess throttle cable back and it quickly hummed down into a much lower idle. After it continued to warm up, it began to waver from slightly higher idle to lower, as if it was trying to kick down lower. I turned it off for about 5 minutes and when I turned it on again to pull it into the garage, the car was idling very low and uneven, but didn't die. Was able to drop it into drive and carefully pull it in the garage, then back in park began to idle high again. I did not test drive, only blipped the throttle to guide it in.

Few things...

Springs. I took off the spring from the throttle linkage to the transmission kickdown rod, which allowed the rod to decrease and lower the idle quite a bit. I assume I have too tight a spring on there. The throttle return springs had to be doubled to try and make it return to idling position, but hasn't helped much. I'll try swapping the springs around to see if anything improves.

Throttle cable. I knew I needed one from a small block, so I purchased one from a 73 Dart with a 318. We began to swap it out but it was different than my old 1 bbl cable. We can't seem to get the cable to return the pedal back upright and the cable to return.

Choke and Carb. I have a brand-new divorced choke installed. Now it could be a couple different things but if I pump the throttle once, the choke plate does not close all of the way like it should. When it's warming up, it then only opens about 50 degrees and not all the way open. This was after 20 minutes of idling. Carburetor is a Carter BBD, only 2k miles on an otherwise NOS carb. I'm not having any other problems with the carb other than stated problems and I don't think it's the carburetor.


View of my carb and my linkage setup. Transmission kickdown return spring is gone in attempts to get the idle down. EGR is blocked off with the gasket and a homemade block off plate with the EGR for good measure.




View of my divorced choke and attachment. I used the Holley 1920 choke rod clip to attach this choke rod to the carb. The choke plate is open only this much after 15 minutes of idling.



Oh my goodness I wrote a novel. This is my first time doing stuff like this and I want to make sure I'll have it smooth running from here. Want to take it for a spin and get the appropriate exhaust!

Those springs should really be nested so they don't bind on each other.

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'73 Gold Duster - /6

It would help if you used the right carb for the application. That is a 318 carburetor. You can tell by the short PCV hose tube on the base of the carb and the fact that the choke eyelet on the side of the butterfly is positioned so that the choke will not fully open.

Your problems with the fast idle stem from the fact that your choke will not open all the way. The vacuum operated choke pulloff linkage is to adjusted in any way like it should be, either.

You also need to reinstall the return spring on the kick down linkage. See that long curved slot on the kick down linkage? The throttle cable stud on the carb should be held against the inner end of that slot. If that linkage will not easily slide all the way up to the carb then you have a problem somewhere in the linkage.

Before you do anything else, you need to read the Super Six article here:

http://www.slantsix.org/articles/supersix/article.htm

And yes, the small spring is supposed to run inside the larger spring.

Try disconnecting every linkage and spring from the carburetor. The throttle should close all on its own and be held open only by the curb and fast idle screws. If the throttle still won't close with nothing but the throttle return spring on the throttle shaft closing it, then there is an internal fault on the carb. If the throttle does close all the way, connect one thing at a time until you find the assembly that is keeping he throttle from closing. Have you adjusted the throttle cable in the throttle cable clamp?

In that supersix article,third picture ,the braket for throttle return spring is mounted above egr valve and not below it.

There number 3017b carter oem number 14-1045 is correct for 77,78 super six. 79 is different. The other one is v8. http://quadrajetparts.com/linkage-c-299_302_330.html

Thanks of replies everyone. I've contacted the PO of the carb and he told me that he already had the correct super six choke linkage on the carb. I began to play around with the springs, finding that putting three springs that are now meshed together worked best for the throttle return, and helped my non-returning pedal. The spring that goes to the kickdown rod is there too. I also removed the little bracket holding my choke rod to the carb linkage, which seemed to be doing more harm than good. Now the carb closes all the way, and with just a touch it flips down all the way vertically like it should. Putting it back into place by pumping it, I figured I'd try to run it. A second later, VAROOM, the engine fired up, but the RPMs were waaay too high. I don't have a tach but it had to be 2000-2500 RPM. Turned the engine off, checked the carb. Choke is still closed, throttle blades are closed and only open if I move the throttle. Didn't have time to mess with it more today, and didn't want to run the engine like that cold.

I'll try to set base idle again with turning the screws in, then turning 2 1/2 turns out to see if that at least cuts the very high cold idle out.

Throttle mixture and idle speed are controlled by three different screws. Fast idle speed is controlled by a fourth screw. Usually you start adjusting the idle mixture screws with the screws 2 1/2 turns out, but there is no set number of turns for the idle or fast idle SPEED screws. The idle speed and mixture most also be set in conjunction with the valve lash and base timing.

Looks like the return springs are mounted too low.Should be on same pin the kick down is on. In the center of throttle connector.

I agree. And the throttle cable is usually mounted on the other side of the throttle stud. The inner portion is where the kick down return spring goes.

Have you move the throttle return spring bracket up? It is supposed to mount on the bolt on the side of the intake above the EGR valve.

So I corrected that throttle sliding bracket, that was wrong. But the throttle cable and kickdown strong needs to be switched? That would cross cross my setup on that throttle stuff on the carb.

UPDATE: turned my car on again. Once again it began to climb in the RPMs, and found that the throttle springs weren't pulling the throttle all the way back to neutral. When I pushed it back to the correct spot, the rpms dropped down to a better cold idle. Would it helped if I placed tighter springs and angled the throttle return springs bracket upwards,?


BETTER UPDATE: Moved the throttle return springs to the throttle stud, resulting in the throttle blades coming all the way close closed. A little adjustments of the two mixture screws and she's idling happily at 700-800. Took for a little ready drive....hmm. Feels like my kickdown needs to be adjusted. Not downshifting when I gun it, and first to second shift hesitates and its a little boggy under harder acceleration. I'm happy that it's drivable now, just to take a gander at the linkage down there.

Picture shows throttle bracket placement. No need to bend anything http://www.slantsix.org/forum/viewtopic ... 8c8ac87777

Assembly and adjustments of this system are so popular, such that those of us attempting the upgrade will benefit greatly viewing completed projects.

Reed, were you able to identify this carb as a 318 BBD by just the choke pull off link/lever? Were there other clues?

And back to Reed's question... Did you raise the throttle return spring attaching bracket to the bolt above the EGR valve?

Also, i observed in the picture that the outer manifold attaching nuts are not nesting into brass washers. Will that prevent manifold expansion/ movement risking cracking the exhaust manifold?

The choke linkage and the PCV valve tubes are the easiest way to tell a slant BBD from a 318 BBD. Slant PCV tubes are longer and have an angle in the tube. 318 BBD PCV tubes are short and straight.

That carb has a build in throttle return spring on the shaft already. Fail safe. Looked at 2 cars ,both returned to base idle with out spring assist. Your carb has this. One anchor point on throttle arm is visable in 3rd picture.Where other end of spring should anchor on base plate not there.May be broke. Here is link. http://www.jeepforum.com/forum/attachme ... tall-1.jpg Thats a jeep carb, but the spring is same .

The linkage takes a little adjusting at the transmission. I can't remember exactly the setup but there may be a set screw you loosen and then you can push the linkage further in or pull it out a little, then tighten the set screw and take it for a drive. If I remember correctly, it's very finicky. 1/4" in or out can be the difference in shifting perfectly or being completely out of whack. I've gotten it set dead on the first time and I've had to get under there and adjust it 10 times to get it where I want it. Just be patient and find the sweet spot.