Stalling at acceleration
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5th Wheeling
Joined: Apr 2012
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Stalling at acceleration
Howdy,
I have a 1968 ford f100 with 240 6, and the Autolite carburetor has some problems. It starts and runs like new, I'm very impressed, but when you try to get it to move, it starves. At first I thought it might be a vacuum advance problem, but if I rev it up until it starts to starve and then pour a little fuel in the carburetor, it revs fine for a second. Now, the confusing part is that there is fuel in the bowl. So I'm getting fuel to the carburetor, but somhow its not getting to the intake from there. I cleaned my main jet out and that made a world of difference, but didn't solve the problem entirely. And anyway, are Autolites good carbs? I've heard mixed opinions about them. Some folks say they'll outlast the engine if kept clean, other say they're crap.
I have a 1968 ford f100 with 240 6, and the Autolite carburetor has some problems. It starts and runs like new, I'm very impressed, but when you try to get it to move, it starves. At first I thought it might be a vacuum advance problem, but if I rev it up until it starts to starve and then pour a little fuel in the carburetor, it revs fine for a second. Now, the confusing part is that there is fuel in the bowl. So I'm getting fuel to the carburetor, but somhow its not getting to the intake from there. I cleaned my main jet out and that made a world of difference, but didn't solve the problem entirely. And anyway, are Autolites good carbs? I've heard mixed opinions about them. Some folks say they'll outlast the engine if kept clean, other say they're crap.
Posting Guru
Joined: Mar 2006
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like everybody else, Autolite made some great carbs, and some not-so-great ones.
the 2100 and 4100 (2 and 4-barrels) are as good as it gets for the street. i'm guessing you're working with an 1100.
sounds like your power circuit is still plugged up somewhere.
the 2100 and 4100 (2 and 4-barrels) are as good as it gets for the street. i'm guessing you're working with an 1100.
sounds like your power circuit is still plugged up somewhere.
Thread Starter
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5th Wheeling
Joined: Apr 2012
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The carburetor is a one barrel, so I suppose that means its a 1100?
The guy I bought it from said he rebuilt it, but some of his setups have lead me to believe he wasn't much of a mechanic...
We've had it apart...3 or 4 times now. Cleaned every jet and adjusted everything. We're completely stumped.
I doubt its the accelerator pump, because no matter how gradual we try to speed up, it still stalls eventually. If we choke it it helps, but its still not enough. Is the power circuit what goes thought the main jet? You can blow thought the main jet itself, but its not free-flowing.
I'm about ready to give up. If I can't figure it out, what other carburetors fit on this? I was told that if I changed the carburetor I'd also have to change the distributor. Is that true?
The guy I bought it from said he rebuilt it, but some of his setups have lead me to believe he wasn't much of a mechanic...
We've had it apart...3 or 4 times now. Cleaned every jet and adjusted everything. We're completely stumped.
I doubt its the accelerator pump, because no matter how gradual we try to speed up, it still stalls eventually. If we choke it it helps, but its still not enough. Is the power circuit what goes thought the main jet? You can blow thought the main jet itself, but its not free-flowing.
I'm about ready to give up. If I can't figure it out, what other carburetors fit on this? I was told that if I changed the carburetor I'd also have to change the distributor. Is that true?
Tuned
Joined: Jun 2003
Posts: 307
Likes: 1
From: South Florida
The proper way to test the accel pump is to open the linkage by hand, look in the carb and see if it sprays.
Not a 100% sure, but in 68 on a 240, I think it should be a Carter carb.
On vehicles this old, you have to check everything, see if you have a dist with centrifugal advance, it matters if you can use a 67 or older 1100.
The older setup controlled the ign advance thru the carb vacuum load.
Check which parts you have.
Not a 100% sure, but in 68 on a 240, I think it should be a Carter carb.
On vehicles this old, you have to check everything, see if you have a dist with centrifugal advance, it matters if you can use a 67 or older 1100.
The older setup controlled the ign advance thru the carb vacuum load.
Check which parts you have.
Postmaster
Joined: Dec 2006
Posts: 3,603
Likes: 10
From: Spokane, WA
The throttle shaft may be worn causing a vacuum leak. Re-bush and replace the throttle shaft...usually overlooked or just not done on rebuilds.
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Posting Guru
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If it is a "Load-o-matic" carb, then you'll need to use a matching Loadomatic distributor. Like one of the earlier posts said, you'll need to nail down exactly what it is you have currently.
But look on the bright side- if you have a Loadomatic setup, you'd want to change it anyway. It was a terribly outdated design by the mid-60s.
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Thread Starter
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5th Wheeling
Joined: Apr 2012
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Yes, the accelerator pump sprays in, we have done that.
It may have been a carter stock, but its definitly an Autolite 1100 now. And I'm fairly certain I have vacuum only, but not positive. How do you tell for sure?
It may have been a carter stock, but its definitly an Autolite 1100 now. And I'm fairly certain I have vacuum only, but not positive. How do you tell for sure?
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5th Wheeling
Joined: Apr 2012
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I cleaned out the high speed circuit as best I could, you can't hardly get into it. That helped. Got it up to 70...with the choke on.
Any tips on cleaning the Autolite 1100? The port on mine goes up and the takes a 90-degree turn.
Any tips on cleaning the Autolite 1100? The port on mine goes up and the takes a 90-degree turn.
Posting Guru
Joined: Mar 2006
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make sure to click the "spark control valve" link, it has a pic of the Autolite 1100, see if yours is the same setup.
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5th Wheeling
Joined: Apr 2012
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here's a good write-up on the Loadomatic. Classic Inlines
make sure to click the "spark control valve" link, it has a pic of the Autolite 1100, see if yours is the same setup.
make sure to click the "spark control valve" link, it has a pic of the Autolite 1100, see if yours is the same setup.
Yep, thats my carburetor. Interestingly enough, when the article describes characteristics of the years they produced certain carburetors, it sure seems like mine is older than '68, when my truck was produced. I took a look under the hood of the 1974 ford 250 at the farm I work at, and noticed that it had a carter, with a more conventional distributor setup. Sure looks to me like they would bolt right up, bummer they still use that ford or I could just steal the parts off it. If I found a later model carburetor and distributor at a junkyard could I just swap them, easy as that?
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5th Wheeling
Joined: Apr 2012
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I glanced over that article again. It says that pre '68 is when they had spark control valves, and pre '67 had one acceloretor pump diaphragm. I'm almost certain, I have a pre '67 carburetor on my '68 pickup.
But I really don't know if I'm having problems with the distributor advance, it sure seems to me like its starving out on fuel. And when I cleaned the high speed circuit, it ran very much better, just not perfect. I'm gonna try again today, maybe get a little imaginative on ways to clean out that port.
But I really don't know if I'm having problems with the distributor advance, it sure seems to me like its starving out on fuel. And when I cleaned the high speed circuit, it ran very much better, just not perfect. I'm gonna try again today, maybe get a little imaginative on ways to clean out that port.