Carter AFB Question ?

[54blackhornet]

I had my choke adjusted this week, it's electric, it would start with one pump of the throttle but would not idle right and fast idle adjustment was not working at all. Well now it starts and idles good when cold but the least little bit of throttle and it back fires thru the carb and just runs like S@IT ? Any suggestion what happened ? I still have the original Qjet but three attempts to get its heat stove choke to work properly where futile ! I thought the Carter electric choke would be an improvement ?....

[Lattimer]

Originally Posted by 54blackhornet

I had my choke adjusted this week, it's electric, it would start with one pump of the throttle but would not idle right and fast idle adjustment was not working at all. Well now it starts and idles good when cold but the least little bit of throttle and it back fires thru the carb and just runs like S@IT ? Any suggestion what happened ? I still have the original Qjet but three attempts to get its heat stove choke to work properly where futile ! I thought the Carter electric choke would be an improvement ?....

Sounds like a possible vacuum leak.

[54blackhornet]

The carb is sitting on one of those aluminum adapters needed to install on a stock manifold. It was running good when warm before adjusting the choke. Crazy ? Thanks for the tip !

[davepl]

Sounds way lean if its popping through the carb. Verify your timing is right before changing anything on the carb. For an automatic trans vehicle you will need the heat stove, heat pipe, proper intake manifold cross over (not blocked), air cleaner with heat stove valve (thermac), not an open air filter element, correctly heated and adjusted choke, proper choke door pulloff, and correct timing, jetting, and accelerator pump at a minimum. If any of these are wrong or missing, it will run like crap when cold. You'll be two-footing it to keep it running and hating life. These were not all emissions devices (especially on trucks in the 60s) they were there to make them run half decent when cold. Too often they get stripped off so someone can stick a Chinese chrome open air filter on it for looks, then it runs like crap, then they change 10 other things to get them to run "right". I'm not saying you, I'm saying me when I was 16.

If fast idle adjustment is not working at all, then stuff is broken. Broken and/or missing parts need to be repaired or replaced to get it to at least the point where it -could- work properly before turning any knobs.

So, check timing. Check for vacuum leaks. Check vacuum door choke pulloff, which is super-important but most people don't. You're going to have to do that one by ear though, as there's no spec for that carb on your application. You could start with the spec from a similarly sized Chrysler or whatever it came off of.

Choke should be fully closed when cold. After starting it opens a certain amount (won't run when closed). If it opens too far, you'll be too lean. Try closing it a little (to about 1/4" gap) by hand, and if that helps, adjust it to be more closed. -That- is the proper adjustment. Adjusting the choke only does two things - set the temp at which is is fully closed and the rate/temp at which it opens later. In the first 3-5 minutes of cold operation it does nothing but hold the door shut during cranking and provide spring tension against the pull-off door during warmup.

If it wants to be closed too much, air is getting in somewhere else. Then you'll be in the position where people start to bandaid things with too much timing, adding a bunch of fuel, drilling holes through throttle blades, and any number of whackadoo things.

Remember, all of this was adjustable for the guy with the 10th grade education at the corner gas station (some of the best old school techs, to be sure). No rocket science, just the right parts set up and tuned correctly.

[54blackhornet]

Thanks for the choke info ! No choke issue now after proper adjustment, now it runs like carp under load ?

[SierraMtns]

I don't know if this will help but I hear good things about this guy.

It might be worth sending the carb in.

http://www.carburetorsandmore.com/index.htm

[Fitz]

Originally Posted by 54blackhornet

I had my choke adjusted this week, it's electric, it would start with one pump of the throttle but would not idle right and fast idle adjustment was not working at all. Well now it starts and idles good when cold but the least little bit of throttle and it back fires thru the carb and just runs like S@IT ? Any suggestion what happened ? I still have the original Qjet but three attempts to get its heat stove choke to work properly where futile ! I thought the Carter electric choke would be an improvement ?....

A Holley is an improvement. Any other solution is just chasing more Carter parts.