When I drive over 35 MPH at a constant speed the engine will "pulsate", revving slightly faster and slower. If I back off on the gas it will stop, and also if I give it significantly more gas it will stop, but it keeps pulsating if, for example, you are on the freeway. This is real Irritating, and I have to either be slowing down or speeding up every time I am going down the freeway. I have recently replaced the points, cap and rotor, and timed the engine. It started happening after I did those things.
Any Ideas???
There is a hole in the carb that sucks air! Is this normal??? It is a Holley R2536 carb. What do you think about this hole?:

This fuel regulator is in-line between the fuel filter and the carb, and I dont know if it is stock and if I should remove it:

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1963 Dart GT

What you are experiencing this jiggles is lean surge. NOT good for engine as this is too much lean.

Check all the vacuum stuff, manifold gaskets etc. Check float level, and clean and rebuild your carb. But test your throttle shaft bushing for wear.

Send it in for rebuild to reputatable rebuilder not the carb swapper shop.

Cheers, Wizard

Hmmm, can't say what that hole on the carb is for but consider taping some duct/duck tape on it and give it a spin. At least you can eliminate that as the cause...

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Slanted D150

As you can see on the right side of the picture showing the hole in the carb, I dont have a throttle lever bushing at all!

Is there a parts source where I can get one?

THX

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1963 Dart GT

It looks like a vacuum tap nipple just fell out of the carb body; probably, it's probably stuck in a vacuum line hanging down somewhere.

I've had an aftermarket fuel pressure regulator stick and cut off the fuel; I'd hit it, and it'd start working again, so I knew that was the problem.

The first easy test would be to remove the fuel pressure regulator to see if that cures the problem.
DD

I am with Doc, I tried running a Cagley and it drove me nuts!!!!!!!!
I had been running a #57 jet in the carb at the time and the Cagley unit just made it worse. It was already lean and the Cagley just wasn't required. If you were running a #60 jet, then the Cagley would be ok.

Yes, on the hole in the carb. I have one like that too. It is about a 1963-67 1920 Holley.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

The bushing that is of more concern is where the throttle shaft goes through the side of the carb. They seem like the first to wear out. You can spray that and other areas with carb cleaner or penetrating oil. If the idle improves suddenly, you've found your vacuum leak.

The hole is normal, but I forgot what it's for..........

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

This is a symptom known as "surge", and it is very frequently (though not always) caused by a lean-mixture condition.
OK, well, this is one of those drivability faults that can be tricky to diagnose, because it is often caused by multiple interrelated factors. What is your base timing set at? Which spark plugs did you install, and at what gap?

Yes. It is supposed to be there, just as it appears in your photo. Nothing is broken or missing. This hole is for calibration of the power valve and vacuum advance. Some carburetors have it, and others don't, but it is not causing your surge. The R2536 is a very early ('62-'63) Holley model 1920 carburetor. What is its general condition? How long since it had a good, thorough disassembly, cleandown, rebuild, and adjustment?
It is not stock, and you should remove it. You may also want to do the fuel line mod while you are at it.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I am going to remove the fuel regulator today. Thanks for all of the good advice! The carb has never been rebuilt as far as I know, but I have only had the vehicle since January. It only has 64k orig miles on it (I was told the "little old lady" story, but this time she was from Bend OR), and other than the fuel regulator I believe that it is all stock. The car wants to stall if I give it too much gas too fast from a stop, but if I accelerate slowly up to about 10 MPH I can give it all the gas I want. I will check the timing again today and repost with the details, as well as results of taking off the regulator. The spark plugs were checked and gapped per the manual at .035.

THX

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1963 Dart GT

Sharp car! You will definitely want to go through the carburetor with a quality kit (top preference is a Walker #15480A) and a new float (Walker #100-14). Carburetors don't like sitting for long periods accumulating no miles; it causes them to gum up and the float to absorb fuel and grow heavy. This rebuild operation will also likely solve the car's hesitation on acceleration that you mention. Whatever you do, don't buy a "rebuilt" (or "remanufactured") carburetor and trade-in the present carburetor as a "core". Doing so dooms you to a long and tiresome battle with carburetors ruined by the so-called "remanufacturing" process.

Going by your picture, you are also missing an important piece of your throttle linkage. There's supposed to be a green rubber bushing securing the car's throttle rod to the carburetor's throttle lever. Without this bushing, there's a lot of slop in the throttle linkage, which makes problems and isn't very safe. You will want to put in a new one right away. The best place to get it is from Gary Goers, who also supplies a whole bunch of other "impossible" small parts for your '63. He doesn't do internet/online ordering.

Gary Goers
37 Amdahl Ln.
Kalispell, MT, 59901

Send him $14 and request one #415 throttle bushing and one catalogue. Have some patience with him, he is only one man making and providing parts nobody else does. And his stuff is top-quality, too.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I removed the regulator and drove the car about 350 miles yesterday (from portland to the other side of Mount Hood and back), and it does drive much smoother, but still with some surge when I am trying to stay at a constant 55-65 MPH. Thank you all for the suggestions!

Thank you Dan for the details for a rebuild kit and that bushing that is missing, those are the next things I will be doing.

One more thing. I would be interested in any thoughts about what the car may be worth.
???

Thanks,
Rick

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1963 Dart GT

Cheap fix for the throttle lever bushing:

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes