Phil1969

Hi
I have a 1969 Mustang that was completely rebuilt around 8 years ago.
Has 351 Windsor and edelbrock carb.
I am having an issue with my electric choke on start up seems to work properly but stalls unless I give it gas.
Looking for someone who can take a look and adjust in the Bowmanville Oshawa area.
Thanks

Lambykin

I know this was posted in May, but after running a little bit, does the engine run on high idle? If you pull the air cleaner, can you confirm the choke plate is closed, too?

Phil1969

Hi
Thanks for responding.
Yes it idles ok after running.
The flap does close also.

Lambykin

Ok, then it sounds like you may not need any adjustment at all. Feel free to get an expert opinion, though. Not knowing if you grew up during the period when your car wasn't very old, but with some cars, it was common to have to "babysit" the car on cold mornings. Depressing the accelerator pedal a few times would set the choke & prime the carb (if equipped with an accelerator pump & automatic choke), but turning the key didn't always mean the car would stay running immediately after ignition. Certainly not uncommon to have to hold the accelerator pedal a bit after initial start. Usually a minute or two is enough to warm the engine so it will fast idle on it's own on a very cold morning.

My family owned Ford products throughout the 70s, and our '72 Meteor behaved exactly the way you describe. It often needed to be babysat for a few minutes. Once it would run on it's own with choke set & fast idle, you could jump out of the car & begin the morning ritual of clearing snow & scraping frost from the windows. Dad also had a '75 Lincoln that didn't exhibit this problem. These were the imperfections of carbureted cars, and if you tried to drive off too soon, the car would certainly protest by unceremoniously stalling - usually as you were attempting to reverse out of the driveway, and just as you were starting to turn the wheel. It would be at this moment where you learn why many cars then had "turn by pinky" steering. :-)

I know you mentioned you have an Edlebrock carburetor, but this doesn't change the behaviour. If you're used to the world today where everything is fuel injected, and starts flawlessly regardless of the weather, you will have to be a little patient with a carbureted vehicle. Each one has it's own nuance, and there is no science to it. Some cars required 5 pumps of the accelerator on a cold morning to prime. Others only 2 or 3, and one press more would result in a flooded engine. Over time you learn the characteristics of your beast - starting procedure wasn't necessarily identical even if you had the same two cars. One of the vehicles in my fleet has a carb - I still appreciate the old days, and can appreciate fuel injection. A lot of people get all nervous working with carbs - probably because they don't understand them.

Hope this helps. If you have any more questions, I'll do my best to answer.

Phil1969

Thanks again for responding.
It is exactly as you described,I need to keep my foot on the gas pedal to keep it from stalling once started.
Then runs fine.
The automatic choke used to do this for me, but things change as you stated.
I will carry on with giving her gas for 1 to 2 minutes then be on my way.
Thanks again for taking the time,great response

Lambykin

You're welcome - just trying to help.


If you still suspect the automatic choke may not be working correctly, there are few simple things you can do to check it. Naturally, you should follow the shop manual for precise adjustments for your Edelbrock carburetor. What I'm about to summarize is a quick check, and will "likely" mean it's ok.

Take the car out one evening for a cruise when you know the next morning is going to be chilly, or cold. Why? You want to warm things up good, and have it at operating temperature for a while. When you park it for the night, pop the cover on the air cleaner to verify the choke plate is completely open.

Next morning (when it's cold out), you want to set the automatic choke, but not start the car. On the cold morning, jump into your car, and fully depress the accelerator 2 or three times. DO NOT start the car at this time.

Pop the hood, check the choke plate on the carburetor again. If it's cold enough, and if it's properly adjusted, the choke plate should be completely closed. While you haven't verified adjustments are specific, you have verified proper operation of the automatic choke mechanism and that the choke plate is properly actuated.

If the test above checks out, I would assume your choke is working normally. In a perfect world, this is where the car should start & run on fast idle. However, the reality is it may, or may not, run on fast idle immediately. As I covered earlier, sometimes carbureted cars required babysitting for a minute or two. If fast idle never happens, and the choke is set, then you might want to look at adjusting the fast idle screw. This will be covered in the manual for the aftermarket carburetor.

If you discover the choke plate isn't closing, or is only partially closed on a cold morning, the following could be culprits:

- Automatic choke needs adjusting (read manual for the how-to)
- Linkages are binding
- Choke plate could be stuck/seized
- Automatic choke could require replacement if everything is free, and adjustment is correct (the bi-metallic spring can wear out, or break completely)

Hope this gives you some more insight if you suspect there is still an issue. I'm not completely clear if fast idle ever occurs on your car. If it doesn't, then you do need an adjustment. Fast idle is where the engine runs typically somewhere between 2000 & 3000rpm. It will remain idling that high until the choke begins to warm up, and slowly pull the choke off. Many carbs you "kick down" with the accelerator pedal after it's warmed up so all of the linkages release properly on the choke. Idle will then return to normal.


To be clear, and to repeat my point, some carbs are adjusted properly, but the vehicle will stall at first. This necessitates holding the accelerator pedal until the engine heats slightly until it will be fine on fast idle. Not all cars will exhibit this behaviour - definitely hit & miss at times.

Lambykin

Maybe to be completely clear, I should ask the following:


1. On a cold day, do you depress the accelerator two or three times before you start the engine?


2. When you start the engine on a cold morning, what happens next?


3. You state after holding the accelerator for a couple of minutes, your car "idles fine." On a cold day, does it ever try to idle fast - like around 2000-3000rpm? Even if the engine requires some initial coaxing by you, it should still want to idle fast until it gets close to operating temperature.

Phil1969

Yes the plate is open after driving and parked.
In the morning I used to push down on the pedal once and the automatic choke would bring the rpm up, I would then push the pedal again and the rpm would drop down to around 650 and away I would go.
Choke seems to be functioning.

Now I push the pedal once in the morning the plate closes, not all the way tho, leaves small gap.


Then it starts no problem it climbs to around 1000 rpm then will drop and stall unless I give it gas.
Never try's to fast idle not really sure why not.


Thanks again

Lambykin

May not be cold enough outside this time of year to see the choke plate fully closed. I'd wait until fall to test this on a very chilly morning. That automatic choke, which is typically a round device, and often with a wire attached to it, is really just a piece of special metal coiled up to act as a spring. It's called a bi-metallic spring, and is sensitive to temperature. It contracts in the cold, and expands as it heats up. This basic operation moves a tab on the carburetor that is attached to a linkage that closes the choke plate. This time of year is not a great test for full choke because it doesn't get cold enough to fully contract the spring.

Regardless, it sounds as if the choke part is working. You may just need a simple adjustment with the fast idle. It's usually just a screw. Proper adjustment is usually done on a cold day when you have full choke. Not uncommon to have to adjust things from time to time on a carburetor. Naturally, everything is mechanical, and things move with expansion & contraction of the metals over time. However, I wouldn't touch anything until we get into much colder weather. If you tinker with choke & fast idle adjustments now, you will find everything to be totally out of whack come cold weather.

What it sounds like to me is you have partial choke, and since it's not full choke, you won't have full fast idle. There's a stepper mechanism involved, which matches the fast idle to the amount of choke there is. It could simply be that the automatic choke doesn't take long to warm up this time of year, and it steps down the idle a little too soon, which is causing the stalling. This, unfortunately, is also a common issue with some carburetors. Sometimes there's an adjustment for this, sometimes there isn't. Totally depends on the carburetor. If you could tell me the model number of your Edelbrock carburetor, I could try to locate some more specific information.

Let's hope there's an adjustment, because if it once worked perfectly fine, then something has changed. Carburetors can be daunting and confusing at first. However, once understood, and once they are adjusted properly, they work just as well as any fuel-injected engine.

gronk49

Where does the wire go to? I bought a 1970 Mustang and the alternator was off. When I reinstalled it I noticed a red wire from electrick choke on carb. Need to know where this get power from.
Also, there is a coolant line that is purposely run a dn supported next to the choke for heat, if I have this do I even need to connect the power?