I have had my 75 Swinger for almost 3 years and this problem has been ongoing pretty much since the beginning. She wants to stall at lights-most stops.

I originally had a Holley 1945 but switched to a Carter BBS last year. The problem pretty much followed. At some point I put in fresh spark plugs (NGK UR5) and the problem would vanish for a week or two and then it would return. When I would pull the plugs a week or two later - some of them would be pretty black looking while the others looked normal. This winter i plan on pulling manifold and having a valve job done - new seats-seals.

I changed out spark plug wires last year.
I have done the fuel line mod.
I have rebuilt the Carter (it was an original - not reman - and was NOS) and verified the fuel float level.

I have checked timing of distributor (5 BTDC)

I have NOT checked timing chain for slack.
I have NOT checked valve lash.

Other than the stalling at stops the car drives fine.
When I stall it usually (but not always) recovers if i give it some quick pumps of gas.

I feel fairly confident that it isn't carb related but I am still very new to all of this so I don't want to declare anything.
I felt like it was power related because when I would change the plugs the problem would disappear but now even that isn't working. I have brand new plugs in and she still wants to stall at lights.

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Valve adjustment needs to be high up on your to-do list. Also yes, it's a good idea to check for a slack timing chain.

Now, about those black spark plugs: are they dry-powdery black? Or are they shiny-gummy black?

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

Here is a pic from the last time I pulled them. I am not certain of the order but my memory is that this is probably right.

This was after a few weeks. In the past, if I left them in longer the darker ones would be very dark.

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I can't see any signs of oil, and if they are bone dry instead of moist, the dark color is caused by fuel . The more fuel there is, the darker the plug color will be. The "ideal" color range with todays fuel would be the third plug starting from the left being the darkest you would want to see and the 5th plug starting from the left being the lightest color you would want to see.

In your particular case, in addition to checking compression and chain stretch, I would check for air leaks . I di this by using flammable brake cleaner with the long nozzle that comes with it then spraying it gently around the carb base and intake where it meets the head . If the rpm goes up, you have a leak.

If there are no leaks, lower your idle to a slightly low setting, then set the fuel mix screw to get the highest idle then turn it back in 1/6th to 1/8th of a turn.

Next, I would then reset the idle to a slightly low setting again then check the timing, then plug the vacuum advance and check the timing again . It should not change.

Leave the vacuum advance plugged then advance the timing 3 degrees and listen for an increase in rpm . If you hear a definite increase in rpm and the engine still runs smoothly, lower the idle again then advance the timing 3 more degrees and listen for another increase in rpm . If it increases again and still runs smoothly, leave it there and set the idle rpm and the fuel mix screw, then take it for a drive. Drive at around 15 mph in second gear then floor it fast and hard until you reach around 30 mph and listen for any sound of pinging from the engine.

If it increases in rpm after the first 3 degrees of advance but barely increases after the second 3 degrees of advance, retard it back to the first 3 degrees of advance point and do the test drive.

You can then try it with the vacuum advance connected to ported vacuum.

NEVER, EVER use brake cleaner for this! The regular kind, still widely available, contains chlorinated solvents that burn (such as when drawn into an engine) to form phosgene gas, used as a chemical weapon -- read about it here. You definitely do not want to take even the slightest chance of getting a whif of it out of the tailpipe or via an underhood exhaust leak. Even the "non-chlorinated" brake cleaners often contain solvents that form very seriously nasty stuff when burned.

Always only ever use carburetor cleaner for a test like this.

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

Power Brakes?

The vacuum for the booster is the #6 runner.

A vacuum leak would lean out #6, and would have some effect on the closer cylinders depending on how far away from 6.


No Power brakes, the plug in the 6 runner could be leaking.

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

To say "NEVER, EVER use brake cleaner for this!", and over emphasize it's potential dangers while not mentioning the potential dangers of the Carb cleaner which was suggested seems a bit extreme to me.

The carb cleaner statement when combined with the rest of the previous post not only implies that it is perfectly safe to use to check for air leaks, which it is NOT, it also implies that it is the only acceptable product to use which it is also not . Just a few of the other products that can be used are listed below and they all vary in effectiveness with water being the safest, although it could turn to into steam.

Propane
Ether (Starting Fluid)
WD 40
Water

You can in FACT use brake cleaner till the cows come home for this app and never have a problem IF the standard level of caution is exercised that should be exercised with any chemical . I repair and restore cars for a living and have been using brake cleaner for this app for 40 years and have zero health problems . The percentage of phosgene gas that may be created in the exhaust by using this product, if in fact any even is, will be so incredibly small that simply breathing the exhaust fumes or even the air in Los Angeles on a hot summer day will likely do more damage than the phosgene gas will.

I am not saying that brake cleaner is 110% safe to use for this app, however, other products that contain chemicals certainly aren't really much, if any safer if they are not used in a well ventilated area just like most warning labels state they shpuld be . I am simply saying that if you use the exact same precautions with brake cleaner that you should with any other chemical like carb cleaner, lacquer thinner, paint, and weed killer etc, which is, use it in a well ventilated area as the labels on these products state, and don't stick your head in the can and start huffin it, you should be just fine . In my experience, it is usually the careless people that get injured by something.


Notice the brake cleaner label says the fumes "may", and "possibly", turn into phosgene but they don't even say how that might happen . It does not state that they definitely will turn into phosgene.

.........................................


The carburetor cleaner label clearly says "VAPORS HARMFUL", so is this a "better" product to get an illness from?

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Contents of B-12 Chemtool carburetor cleaner that are health hazards without even exposing them to high heat.

ACETONE
2-BUTOXYETHANOL
TOLUENE

ACETONE

Exposure Routes

inhalation, skin absorption, ingestion, skin and/or eye contact


Symptoms

Inhalation of Acetone fumes can cause narcosis, irritation of the respiratory tract, stomach and small intestines . It also builds up in the body over time with repeated use.



2-BUTOXYETHANOL

Exposure Routes

inhalation, skin absorption, ingestion, skin and/or eye contact


Symptoms

irritation to eyes, skin, nose, throat; hemolysis, hematuria (blood in the urine); central nervous system depression, headache; vomiting


Target Organs

Eyes, skin, respiratory system, central nervous system, hematopoietic system, blood, kidneys, liver, lymphoid system

.

Hi Guys,

You're both right.

Dan is correct to warn of phosgene hazard; seems to me he's just trying to help others - chlorocarbon combustion will produce phosgene, albeit in low concentrations under the conditions we're discussing, and at the other end of the car than one would be working. Still, good ventilation is warranted for any such activity.

Barnett468 is correct to point out that many other organic compounds carry dangers. Plain old hexane is a neurotoxin (so is ethanol, but we still drink it). Many organics are highly flammable, cause liver damage, cancer, etc.

The key is to realize that we must take all this information with a grain of salt. Safety precautions were developed because of accidents that happened, discovery of illnesses caused by chemicals, etc. - however, typically, not always, but typically this was due to e.g. a massive overexposure, an explosion, crazy irresponsible behavior, and the like.

As an organic chemist, I can tell you that most organics are relatively safe if you handle them safely. All organics should be used in well ventilated areas and any flammables should be used with arms length care and mindfulness to sparks or other ignition sources. Many of the warnings are based on testing which involves massive overexposure of the chemical to get a positive result for the outcome. Chloroform is now "very dangerous" but in the old days it was in cough syrup and used regularly as an anesthetic. My organic chemistry professor and his ilk regularly washed their hands with benzene, a known carcinogen, and he's healthy as a horse at 80 years old. Of course there are a few chemicals that are deadly or carcinogenic at very low concentrations, but these are few and far between (don't eat the wrong mushroom, your liver can be destroyed in a matter of hours).

Anyway, I was going to comment on propane, I heard that was a good one for checking for intake leaks. Seems to me that a gas is the easiest to use and doesn't stain or remove your intake paint job....chlorocarbons are great paint removers and carb cleaner can fade your paint.

brian

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https://tinyurl.com/yynpj4v2

It looks like the brake cleaner wont cause blood in my urine so i think i will use that instead of the carb cleaner.

I wouldn't want to get burnt by all the hot steam by using water.

Towerofpower,

Continuing on my toxicity and what is bad for you theme...besides water (steam) burning you, water itself is toxic...if you drink enough, water can kill you. Drink enough pure (distilled) water, lower your electrolytes enough, you'll go into shock and die. My point is, we need to take things into context when we read danger warnings on labels.

If I said, "water is toxic" people would generally scoff and dismiss me as a crazy head. That's not far off from people reading safety labels and never using a product again because the label said it is toxic in some way. These safety warnings were mandated because of years of research and government regulations culminating in a compromise.

brian

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https://tinyurl.com/yynpj4v2

Hello Brian;

One of the difficulties with using propane is that, since it is a gas, it is possible for it to get into the top of the carb during testing under some circumstances which can give a false reading . It can also get heavily diluted by the air coming from the radiator fan which will reduce its effectiveness.

The main reason I use brake cleaner, is that in my experience, it seems to have more affect on engine rpm than some of the other things I mentioned, which makes it easier to tell if there is a leak or not, especially if the leak is small which in many cases they are.

Yes, brake and carb cleaner can be hard on paint, and it is definitely good to point out that it, and other chemicals, can dull paint in some cases, therefore, with this additional info, people can make a more informed decision as to what they want to try.

Hi guys. I t is great to see all of these minds full on knowledge, wisdom, and experience helping. Thank you for all your input.

The situation you've described sounds like a leak in the power break booster. (if you have power breaks)

disconnect (at the booster's end) the hose that runs from the intake to the booster and plug it with something. Then go and press on your break peddle. If the engine does not want to stall, then you have found your problem.

(Note: your break peddle will be very stiff with the hose disconnected)

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Slant power!!!
At least I try...