The Ford Barn

malloyjp · 10-09-2014, 11:52 AM

I have a 1969 autolite 2100 and I'm trying to dial in the fast idle setting. The book calls for 1600 rpms on fast idle. I know the adjustment screw rests on little steps that drop the idle down. But I can barely see in there to know what's going on or how to correctly adjust it. Is there a methodical way to get this thing set to 1600 rpms on start up other than trial and error ? Also, it has an automatic choke setup. I've played around with moving the black plastic cap for lean and rich settings. I suppose that determines how fast the spring inside expands to open the choke, but I'm not seeing a whole lot of difference when I adjust the cap. What are people's experiences with these auto choke adjustments ? I'm wondering if I'm doing something wrong of if the whole thing is just a cruel joke by Ford. Thanks !

oj · 10-10-2014, 11:31 AM

With the engine not running roll the throttle wide open and from the passenger side of the car you will see the highspeed adjusting screw barely exposed, use a 1/4" boxend wrench on it to screw it in (higher high idle speed) or back it out for lower idle speed.
You have to adjust it and see where you are at when the choke is fully open and warm, you can't adjust it then start the car - it has to go thru the warmup process. During the process you cannot touch the throttle or the cam will trip out. With engine cold you push gas pedal to the floor and engage the automatic choke, start engine and resist touching the gas pedal, allow engine to run on its' own, the choke plate will be opening and the idle speed increases, when fully open the idle will be ripping right along - you can't touch the gas pedal during any of this process else the high idle cam will drop out and the throttle blades return to closed position.
You realy have to have the engine properly tuned to get it right.

malloyjp · 10-13-2014, 03:54 PM

my car sat for a week, I live in PA and it's starting to get colder (50s today). Anyway, I fired it up and watched the tach. On cold start it initially read about 1400 rpms, and the rpms slowly started to drop to about 1100 and engine was running pretty rough (engine shaking a bit). Once I tapped the gas pedal, the engine smoothed out and rpms began to rise. I had air cleaner on, so wasn't following the choke. I assume by hitting the pedal the choke began to open more. I just watched it and rpms rose to about 1750 on its own. I let it warm up and hit the gas pedal again , this time it dropped down to it's curb idle speed and it ran fine.

I've been tinkering with this car for some time. I have the timing set right, the points/rotor/cap are new, plugs and wires are fairly new. My only issue right now is getting it to run smoothly on cold starts. If I start it every day, it's better. If I let it sit for several days , it's worse. But once it's warmed up it runs well. I'm not sure why the car would stumble and run rough on cold starts. I'm assuming it's a carb setting, but guess could be anything. Any ideas on how to get an old car to run well when cold ? Thanks !!!

ems customer service · 10-14-2014, 12:15 PM

remember todays gas is not the same as when these carbs were built,, we are running more volume of fuel with less energy, all the epa crap added and alcohol make carb adjusting a bear

oj · 10-15-2014, 07:34 AM

When starting push the gas pedal all the way to the floor before cranking the engine - this will engage the choke. The engine will run rough because it'll have too much fuel and no air until the choke begins to open allowing more air and the rpm will continue to increase as the choke opens.
It sounds like you started the engine without engaging the choke (your initial high rpm) and then engaged the choke when tapping the throttle.
I have to battle this problem often, we don't drive these cars as much as the designers intended. When we do drive them the trips are shorter and the plugs do not get as clean as they should, they get carbon fouled and having clean plugs is the key to easy & smooth engine starts. Pull your plugs right now and you'll see both extreme carbon and raw fuel fouling the plug - that is a big contributor to what you are experiencing.
You might try a higher heat range in your plugs, that will help to keep them clean. Have your O2 checked when engine is warmed to running temp on idle, your idle circit may be too rich adding to the carbon fouling. Have a look at your ignition system itself, good wires? etc

willowbilly3 · 10-16-2014, 06:36 PM

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Those were a piss poor and finicky choke when new. The heat tubes all need to be in good order and generally rotted off the manifold in a couple years. I have done some comparing and came up with an electric cover from a newer 2150 carb, maybe late 70s and it helped, but it don't help the lack of notches on the cam. In real cold weather, it's either screaming or kick it once and it's dieing. I fiddled with some I drove brand new and never found a middle ground, neither could the Ford garage. In frustration, I started hoarding the 69 and earlier pickup carbs for the manual choke stuff and converting them. The last 2 I had got robbed for the pair of 2100s I have on the 260 in my rpu.

10-09-2014, 11:52 AM	#1
malloyjp Junior Member Join Date: Jul 2014 Location: Phoenixville , PA Posts: 28	Autolite 2100 - adjustment questions I have a 1969 autolite 2100 and I'm trying to dial in the fast idle setting. The book calls for 1600 rpms on fast idle. I know the adjustment screw rests on little steps that drop the idle down. But I can barely see in there to know what's going on or how to correctly adjust it. Is there a methodical way to get this thing set to 1600 rpms on start up other than trial and error ? Also, it has an automatic choke setup. I've played around with moving the black plastic cap for lean and rich settings. I suppose that determines how fast the spring inside expands to open the choke, but I'm not seeing a whole lot of difference when I adjust the cap. What are people's experiences with these auto choke adjustments ? I'm wondering if I'm doing something wrong of if the whole thing is just a cruel joke by Ford. Thanks !

10-10-2014, 11:31 AM	#2
oj Senior Member Join Date: May 2010 Posts: 293	Re: Autolite 2100 - adjustment questions With the engine not running roll the throttle wide open and from the passenger side of the car you will see the highspeed adjusting screw barely exposed, use a 1/4" boxend wrench on it to screw it in (higher high idle speed) or back it out for lower idle speed. You have to adjust it and see where you are at when the choke is fully open and warm, you can't adjust it then start the car - it has to go thru the warmup process. During the process you cannot touch the throttle or the cam will trip out. With engine cold you push gas pedal to the floor and engage the automatic choke, start engine and resist touching the gas pedal, allow engine to run on its' own, the choke plate will be opening and the idle speed increases, when fully open the idle will be ripping right along - you can't touch the gas pedal during any of this process else the high idle cam will drop out and the throttle blades return to closed position. You realy have to have the engine properly tuned to get it right.

10-13-2014, 03:54 PM	#3
malloyjp Junior Member Join Date: Jul 2014 Location: Phoenixville , PA Posts: 28	Re: Autolite 2100 - adjustment questions my car sat for a week, I live in PA and it's starting to get colder (50s today). Anyway, I fired it up and watched the tach. On cold start it initially read about 1400 rpms, and the rpms slowly started to drop to about 1100 and engine was running pretty rough (engine shaking a bit). Once I tapped the gas pedal, the engine smoothed out and rpms began to rise. I had air cleaner on, so wasn't following the choke. I assume by hitting the pedal the choke began to open more. I just watched it and rpms rose to about 1750 on its own. I let it warm up and hit the gas pedal again , this time it dropped down to it's curb idle speed and it ran fine. I've been tinkering with this car for some time. I have the timing set right, the points/rotor/cap are new, plugs and wires are fairly new. My only issue right now is getting it to run smoothly on cold starts. If I start it every day, it's better. If I let it sit for several days , it's worse. But once it's warmed up it runs well. I'm not sure why the car would stumble and run rough on cold starts. I'm assuming it's a carb setting, but guess could be anything. Any ideas on how to get an old car to run well when cold ? Thanks !!!

10-14-2014, 12:15 PM	#4
ems customer service Senior Member Join Date: May 2010 Location: detroit mich Posts: 162	Re: Autolite 2100 - adjustment questions remember todays gas is not the same as when these carbs were built,, we are running more volume of fuel with less energy, all the epa crap added and alcohol make carb adjusting a bear

10-15-2014, 07:34 AM	#5
oj Senior Member Join Date: May 2010 Posts: 293	Re: Autolite 2100 - adjustment questions When starting push the gas pedal all the way to the floor before cranking the engine - this will engage the choke. The engine will run rough because it'll have too much fuel and no air until the choke begins to open allowing more air and the rpm will continue to increase as the choke opens. It sounds like you started the engine without engaging the choke (your initial high rpm) and then engaged the choke when tapping the throttle. I have to battle this problem often, we don't drive these cars as much as the designers intended. When we do drive them the trips are shorter and the plugs do not get as clean as they should, they get carbon fouled and having clean plugs is the key to easy & smooth engine starts. Pull your plugs right now and you'll see both extreme carbon and raw fuel fouling the plug - that is a big contributor to what you are experiencing. You might try a higher heat range in your plugs, that will help to keep them clean. Have your O2 checked when engine is warmed to running temp on idle, your idle circit may be too rich adding to the carbon fouling. Have a look at your ignition system itself, good wires? etc

10-16-2014, 06:36 PM	#6
willowbilly3 Senior Member Join Date: Sep 2011 Location: Black Hills, SD Posts: 577	Re: Autolite 2100 - adjustment questions Sponsored Links (Register now to hide all advertisements) Those were a piss poor and finicky choke when new. The heat tubes all need to be in good order and generally rotted off the manifold in a couple years. I have done some comparing and came up with an electric cover from a newer 2150 carb, maybe late 70s and it helped, but it don't help the lack of notches on the cam. In real cold weather, it's either screaming or kick it once and it's dieing. I fiddled with some I drove brand new and never found a middle ground, neither could the Ford garage. In frustration, I started hoarding the 69 and earlier pickup carbs for the manual choke stuff and converting them. The last 2 I had got robbed for the pair of 2100s I have on the 260 in my rpu.