What would cause a carter to bog or hesitate during both hard and light acceleration??
Carb has been rebuilt but still wants to act up a bit.

What would cause a carter to bog or hesitate during both hard and light acceleration??
Carb has been rebuilt but still wants to act up a bit.

Hey,
How do I get a job as a train driver in your area!! LOL.

Right off the top of my head I would say your accelerator pump but you say it's been rebuilt so that should be ok. Another thing might be leaking throttle shaft. If it's hard to adjust the idle on it (air fuel mix screws) and it idles high grab the throttle shaft and see how much play is in it. There should be only a SMALL amount of movement. Also you can spray some carb cleaner, WD40, or something like that around the throttle shaft and if the idle changes you have a leak. The way to check your accel pump is to look in the carb and see how much gas squirts out when you pump the throttle. You should see a nice strong stream of gas shoot out every time you hit the throttle. Check with the engine off, it's easier to see. Of course you can pump the reservoir dry whith the engine off so if it quits shooting gas after a couple of pumps that's ok. It could be other things in the carb but the above are easy to check.

Uneasyrider

The question(s) would be which Carter, on which engine, with which transmission, and is the combination stock or modified?

Jon.

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by carbking:
The question(s) would be which Carter, on which engine, with which transmission, and is the combination stock or modified?

Jon. <HR></BLOCKQUOTE>

I agree but it's always a good idea to look at the basic operation of the carb and make sure that at least the carb itself is functioning right first. After that I would look at the rest of the story. It's like the mechanic that get's the car that wont start in and replaces a bunch of stuff before he finds out it's out of gas if you see what I meen. http://forums.performanceyears.com/g.../icon_wink.gif As a matter of fact we are also just assuming that the carb is the problem! I can say for a fact that there are many times a carb was blamed for ignition system problems. Just something to keep in mind. http://forums.performanceyears.com/g.../icon_wink.gif

Uneasyrider

Hey thanks,
Yea, the pump seems to be functioning fine. It was replaced when I rebuilt it. It ran well after initial install, strong right off the line. Now it wants to bog or hesitate or whatever you call it.
Oh yea, it's a 65 carter 3896-S with stock manifold on a 66 389 w/turbo hydramatic. Engine and car are all bone stock. It runs and idles just fine with adjustment screws responding well easily adjusting mix, according to a vacuum guage.

If the hesitation is only from idle, try setting the idle mixture control screws for a slightly leaner mixture.

If the hesitation occurs at any RPM when you try to accelerate, I would start eliminating possibilities (ie. timing, valves, distributor vacuum advance, fuel filter, etc.). After ascertaining that compression, valve timing, ignition, and fuel delivery system were all good, then it would be time to remove the top from the carburetor and check the condition of the vacuum pistons, vacuum piston springs, and metering rods.

Jon.

Hey, thanks Mr King.
I'm a little confused, which way would be for a leaner mixture, turned in (clock wise) or turned out?? Is it a trial and error thing, turned in or out, try it and so on??

On this carburetor:

Turn the idle mixture control screws in until lightly seated, and then back them out 1 full turn each.

Turn the idle air screw in until lightly seated, and then back it out 1/2 turn.

Start the engine, and run at a fast idle until the engine is fully warm. Now use the idle air screw (the big one) to adjust the idle to the proper RPM (500 in drive if no A/C, 575 in drive with A/C).

Now turn the idle mixture control screws out (no more than an additional 1 1/2 turn, probably no more than 1/2 turn, and maybe nothing at all) to get the best (smoothest) idle quality.

DO NOT ATTEMPT TO USE A VACUUM GAUGE WHEN ADJUSTING IDLE ON THIS TYPE CARBURETOR.

Jon.

Jon,

Blatant Hijack!

You ever get that money I sent you for the t quad?

Tom V.

Otherwise I need to request a tracker.

Hi hyjacker, you need a tracker! Seriously Tom, no, it has never arrived.

Aren't you worried that your Holley reputation will suffer talking about thermoquads in public http://forums.performanceyears.com/g.../icon_wink.gif

Jon.

Ok, thanks CarbKing!

Happy Holidays...