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Discussion Starter · #1 ·
January 2020 I picked up my 63' Galaxie and I love her!! It's been a long time since I've driven and maintained an old carb'd car. The car drive nicely all summer and then as Fall arrived my car started getting a surging idle. It surges worse as the engine gets warmer and will stall if I don't babysit the throttle. The surging clears out in higher RPM's. Any thoughts?

One more question. What degrees is the ideal timing for a stock 390FE? My car sometimes is difficult to start when cold and sitting for a week so I'd like to verify timing.

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1963 Galaxie 500 Fastback
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@Foxbody817 generally FEs like 10-13 degrees initial timing. If you advance the timing too far it won't start. How does it idle once warm? Do you have to babysit the throttle when you start braking or only once at a complete stop? It might need some slight tweaks to air idle adjustment and fuel on the carb?
 

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Discussion Starter · #4 ·
Check that the vacuum advance diaphragm is holding steady. Get a vacuum tester and connect it to the either the hard line at the carburetor or if you have a rubber line that plugs on the vacuum advance.
You timing should be around 8* and the point dwell 30*.
Thank you for the advice. I ordered a vacuum gauge yesterday after reading your message and will report back once I've had time to start her up and do some diagnostics. I also need to learn how to do a dwell test.

@Foxbody817 generally FEs like 10-13 degrees initial timing. If you advance the timing too far it won't start. How does it idle once warm? Do you have to babysit the throttle when you start braking or only once at a complete stop? It might need some slight tweaks to air idle adjustment and fuel on the carb?
Thank you, I will check my timing (after I receive my vacuum gauge) and if it's not timed right I will start at 10* and work from there.

The idle started to be off just a bit once I would come to a stop at a light but nothing I had to correct with the throttle. I parked it in the garage and started it up a week later and on choke it started and idled just fine until the engine got to about 140* coolant temp which then the idle started slowly surging down and up and steadily got worse. I turned it off, checked around the hood for anything obvious and things looked OK. The next day I fired her up and she ran just fine. The next time after that and every time since it has been back to surging to the point it'd stall during warm up. I have to babysit it with constant throttle in order to prevent surge/stall.

It's snowing outside currently so there's no more driving this car for a while. All I can do is start her up and idle in the garage but I can do a lot with those restrictions. Maybe there's a vacuum leak somewhere that's not visible.
 

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You may have some dirt in your idle air bleeds or elsewhere in the carb. The fact that it runs fine on startup and gets worse suggests it's a problem with the idle circuit. Could be something as simple as resetting your idle mixture screws. Now that you'll have a vacuum gauge, you can dial those in more precisely by adjusting them for maximum idle manifold vacuum. Your idle speed screw may have also slipped over the season, so might simply need to be reset--do that after you adjust your air/fuel mixture to get your desired curb idle speed. The factory procedure is to set the idle speed (and the mixtures for that matter) in drive with the parking brake on and wheels blocked, but it can be done in park. In other words, true "curb idle" is the idle speed when you are in gear idling, will be faster when you're in park with no load. All the above assumes the problem is with the fuel system. Of course, rule out timing and vacuum issues as well. If you have no luck with basic tune up procedures, it may be time for a carb overhaul. Worth checking your spark plugs,, plug wires, points, condenser, cap. That kind of stuff just needs going through every so many years. On cars I have bought with unknown history, this stuff gets done just for peace of mind right away. Those are some good winter projects for you, and very doable DIY jobs.
 

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Discussion Starter · #8 ·
You may have some dirt in your idle air bleeds or elsewhere in the carb. The fact that it runs fine on startup and gets worse suggests it's a problem with the idle circuit. Could be something as simple as resetting your idle mixture screws. Now that you'll have a vacuum gauge, you can dial those in more precisely by adjusting them for maximum idle manifold vacuum. Your idle speed screw may have also slipped over the season, so might simply need to be reset--do that after you adjust your air/fuel mixture to get your desired curb idle speed. The factory procedure is to set the idle speed (and the mixtures for that matter) in drive with the parking brake on and wheels blocked, but it can be done in park. In other words, true "curb idle" is the idle speed when you are in gear idling, will be faster when you're in park with no load. All the above assumes the problem is with the fuel system. Of course, rule out timing and vacuum issues as well. If you have no luck with basic tune up procedures, it may be time for a carb overhaul. Worth checking your spark plugs,, plug wires, points, condenser, cap. That kind of stuff just needs going through every so many years. On cars I have bought with unknown history, this stuff gets done just for peace of mind right away. Those are some good winter projects for you, and very doable DIY jobs.
I have the factory 4bbl carb on my 390FE, do you know what model or part# is it? I'd like to order a rebuild kit and gaskets for it just in case. I'm curious how tempermental these cars are once it starts getting near freezing at night and warms up slightly during the day? Maybe I naturally need to adjust the carb for cold weather?

I've been watching a ton of youtube video's like Uncle Tony's garage (mopar guy) & Thunderhead289, is there any other resources that focus more on the 390FE w/ 4bbl carb?

What's a good 4bbl replacement carb if I decide to go that route? This car is just a cruiser but I'll likely throw some headers and a cam at it this next summer.
 

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Discussion Starter · #9 ·
Make sure the choke is opening all the way.
I will double check that next time I start the car. When I first bought the car the choke didn't work and stayed open when the engine was cold. I figured the car had starting issues because when I bought the car the gentlemen already had the car warmed up and he admitted it was a little tough to start during winter. I adjusted the choke spring and it helped a lot but maybe it's out of adjustment again? I'll soon find out.
 

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You could just give it a quick cleaning without a thorough rebuild. Take it off the car and flush out the passages with carb cleaner as best you can, at least to see if the problem is just dirt. this is just while waiting for parts to arrive. I believe surging idle is usually the result of a lean condition, so stuff in the idle circuits could be the culprit.
 

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Discussion Starter · #14 ·
You could just give it a quick cleaning without a thorough rebuild. Take it off the car and flush out the passages with carb cleaner as best you can, at least to see if the problem is just dirt. this is just while waiting for parts to arrive. I believe surging idle is usually the result of a lean condition, so stuff in the idle circuits could be the culprit.
That carburetor is probably the easiest to repair. It is possible that if someone installed the choke spring backward it closes when heated. I know most people jump on the internet and order a new Edelbrock but try keeping the original.
I've been around Foxbody 5.0's most my life and I learned a long time ago to not just throw parts at it, I'd rather diagnose the problem and fix it. I'll begin with checking to see if my choke is working properly, checking timing, and spraying around the carb/manifold to see if there's any vacuum leaks. Per your advice, I may just take the carb off and clean it since it's winter and I have time. Thank goodness I have a heater in my garage.

In the spring time my son (13) and I are converting the four wheel manual drum brakes to Wilwood discs 😎
 

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I have the factory 4bbl carb on my 390FE, do you know what model or part# is it? I'd like to order a rebuild kit and gaskets for it just in case. I'm curious how tempermental these cars are once it starts getting near freezing at night and warms up slightly during the day? Maybe I naturally need to adjust the carb for cold weather?

I've been watching a ton of youtube video's like Uncle Tony's garage (mopar guy) & Thunderhead289, is there any other resources that focus more on the 390FE w/ 4bbl carb?

What's a good 4bbl replacement carb if I decide to go that route? This car is just a cruiser but I'll likely throw some headers and a cam at it this next summer.
Unless you want to stay absolutely stock 600 cfm vacuum secondary, is a great carb for a 390 and it can be had with electric or manual choke if your car is an automatic make sure to get one with Ford auto trans kick down setup 😉.
 

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Discussion Starter · #17 ·
Unless you want to stay absolutely stock 600 cfm vacuum secondary, is a great carb for a 390 and it can be had with electric or manual choke if your car is an automatic make sure to get one with Ford auto trans kick down setup 😉.
My car is 98% factory stock but I'm very prone to the "mod bug". What CFM is the stock Ford carb? Holley would be my choice if I was to upgrade.
 

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Discussion Starter · #19 ·
If it's an Autolite 4100 chances are very good it's no more than 500 cfm, 600 cfm were available but later, and their rare. If it's a 2 barrel..... size is SMALL lol 😆. 600 Holley is perfect.
It's a 4bbl. Maybe a Holley 600cfm will be in my future if it'll be a performance upgrade. A manual choke would be nice too if that's an option.
 

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The Autolite 2100/4100 is regarded by many to be the “best carburetor ever”. It is still very much a strong performer, and some of today’s best replacement carbs are merely knock-offs of the design. They can run a long time between rebuilds. The only fair knock on them is the cumbersome choke setup. If you can get it dialed in, though, it is quite nice and works very well. The trouble really is that Ford’s manuals did a poor job of articulating the procedure for setting them up, and much misinformation has been spread as a result of the gaps they have forced the end-user to fill in.

Bottom line: Please don’t change it, there is no reason. The ford engineers knew what they were doing. Adding CFM is often a misstep that guys make trying to improve performance, but if other mods are not made first, it will not help at all, will possibly hurt performance. As mentioned, the solution to your current issue is likely something simple, and warrants a methodical diagnosis. If it was running well before, you can get there again with minimal investment, almost certainly.

This is a post I made on the Vintage Mustang forumthat attempts to fill in some of the gaps that Fordshop manuals leave on choke operation…


…possibly beyond the scope of this discussion, but I hope it will help some people.
 
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