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'66 170 autolite 1100 carb only idles only on choke

Gas Pig

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Oct 19, 2005
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Years of never having a problem and now 2nd year in a row my '66 is having carb issues. Just like last year something in idle circuit of the carb is messed up. Last year I just cheated and threw on a fresh rebuilt carb it needed it anyways.

My '66 only runs with the choke 1/4-1/2 pulled out. If I push the choke all the way she dies instantly.

Do you guys think it will clear in time with tank of fresh gas or maybe a can sea foam? Or is this something I need to break down the carb and clean/rebuild it?

Thanks and input would be appreciated, jeff
 

B RON CO

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Hi, it might improve on its own. Does it sit all winter, that might be part of the problem. You know running with the choke pulled is giving a rich mixture. If it doesn't get better you will have to rebuild the carb. Can you do that yourself? You are better off looking inside the carb for dirt.. You might not need the rebuild kit if you don't rip any gaskets. Good luck
 
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Gas Pig

Gas Pig

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Hi, it might improve on its own. Does it sit all winter, that might be part of the problem. You know running with the choke pulled is giving a rich mixture. If it doesn't get better you will have to rebuild the carb. Can you do that yourself? You are better off looking inside the carb for dirt.. You might not need the rebuild kit if you don't rip any gaskets. Good luck

Yeah I did fire her up a few times with out any issues over the winter. I wanted to it more but you know how that goes. I'm first going to put some new gas in it just for safe and easy measures but I don't think that's going to do it.

Yes I'm handy enough to pull a carb apart and clean it but I'm definitely not a carb expert by any stretch. But it really shouldn't be needing a rebuild but I can see the carb getting funny after sitting most of the winter and spring.
 

NC-Fordguy

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I had a similar issue on my 1100 a few years back. Went through the carb several times and could not get it to run right unless the choke was partially engaged. I'd get frustrated, lay tools down and go in the house. Come back and try again later.

Finally I just happened to see the problem-- saw an ever so slight squirt of fuel from the accelerator pump housing. The housing was warped likely from being over tightened over the years.

I did try to straighted in out on an anvil by lightly tapping it but it cracked. I found a couple of 1100s at a u-jerk yard in the trunk of a falcon and the housings were good. Installed it and problem solved.
 

okie4570

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Rebuild kits are cheap at any parts store. I had the same issue on my 66' when I bought it.
 

TDubya

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Aug 3, 2009
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Fortuna, CA
On mine the choke cable is also attached to the throttle linkage. At 1/4" out, the choke is open, but holds the throttle open slightly, kind of working like a hand throttle at that point.
 

CraigS

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Jun 14, 2001
Messages
368
How many new fuel filters have you put on it? Sounds like the idle circuit is plugged. What happens when you give it throttle with the choke off? Another possibility alluded to by NC-Fordguy is you need the enrichment due to a vacuum leak somewhere.
 

bmc69

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I end up cleaning (sometimes with a rebuild kit..other times reusing the gaskets) the one on my '67 every couple of years, thanks to ethanol in the gas and not running it very often. It is always the idle circuit that goes first.
 

jdbronco

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Panama City Beach
Back when I first got mine running with the 6 cylinder, I had to clean the carb multiple times because the gas cleaned everything out of the tank and lines and sent it to the carb. One time I got away with taking the idle mix screw out and spraying a little cleaner into the hole but the other time I had to take it apart and dip it to get it to work right. The tiny passages catch the junk. Mine wasn't dying instantly but didn't run well. You might have a vacuum leak on top of it.
 
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Gas Pig

Gas Pig

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Ok back on it!

Hey guys thanks for all the responses! I got tied up with work then it rolled into a much needed family vacation but I'm back on it now!

I will go through the carb as everyone said but as the vacuum leak where and how should I test???

I did check the carb body screws where good also the accelerator pump housing looks new. The carb was NOS reman from Ford and looked great but who knows if it sat to long on the shelf???

Also I'm not running the original vacuum/fuel pump on it. The vacuum part is still hooked up but prior owner disconnected the fuel portion side of things and installed a electric pump. I did swap it out with a newer pump and filter before the pump. I also have a clear filter right before the carb so I can keep tabs on it too.

Just today I put in fresh gas and it seems better but not as good as it ran at the end of last year.

Any additional thoughts???
 

norm02

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Hey guys thanks for all the responses! I got tied up with work then it rolled into a much needed family vacation but I'm back on it now!

I will go through the carb as everyone said but as the vacuum leak where and how should I test???

I did check the carb body screws where good also the accelerator pump housing looks new. The carb was NOS reman from Ford and looked great but who knows if it sat to long on the shelf???

Also I'm not running the original vacuum/fuel pump on it. The vacuum part is still hooked up but prior owner disconnected the fuel portion side of things and installed a electric pump. I did swap it out with a newer pump and filter before the pump. I also have a clear filter right before the carb so I can keep tabs on it too.

Just today I put in fresh gas and it seems better but not as good as it ran at the end of last year.

Any additional thoughts???

Buy some carb cleaner and spray some of it around the base of the carb, the throttle linkage, carb body, and anywhere that you have a line screwed into the carb. Also spray around the PCV valve. If the idle speed increases, then you've got a vacuum leak at the area that you just sprayed.

Would help to attach pictures of the fuel pump that's on it and the plumbing of the carb. You may have a mismatch of parts that won't allow it to run as well as it's capable of running.
 
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Gas Pig

Gas Pig

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Still no go with choke off

Ok I sprayed for vacuum leaks and didn't find any. Then I removed the carb and carefully took the top off of it. I did find junk in the bottom of the bowl... blackish/brown fussy junk. So I carefully clean the bowl out. Next I shot carb cleaner into every port I could find. I figured that has to be it reinstalled the carb and fired right up. But still after getting up to operating temp I still need 1/3 of the choke on for it idle. She ran a bit better but not anywhere like she use to. Like I stated before I didn't change anything from when I put it away from last fall and she even ran fine the couple of times over the winter.

I'm figuring either I didn't actually clean the junk out well enough and I need to break the carb down further to get it clean or I'm overlooking an obvious vacuum leak?

Ok side point to make last year I had a start of a exhaust manifold leak... and now it is worst then last fall. I can see that could cause it not run at its best but not to be able idle. Agreed? I'm have the new exhaust manifold gasket hopefully will put that in tomorrow.
 

Jdgephar

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Sep 25, 2012
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Most issues that I've had with engines that only run when the choke is pulled is because of junk stuck in the jets of the carb....tractors, lawn mowers, etc. Make sure the jets for the mains are clear, make sure the idle circuit is clear, and the floats are correct. Pulling the choke opens the throttle plates a little bit, letting it get more fuel.
 

okie4570

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Agree with above. Before I rebuilt mine, it sit for 30 minutes in a solvent bath, then solvent rinse. Rebuilt and wow what a difference it made.
 

jdbronco

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Panama City Beach
Get you a paint can of carb dip. I have cleaned carbs before by spraying them and still had issues. Then after 10 minutes in a dip bucket they ran like a champ. There's just some passages in carbs that you can't get clean enough without it.
 

norm02

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Feb 8, 2016
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Get you a paint can of carb dip. I have cleaned carbs before by spraying them and still had issues. Then after 10 minutes in a dip bucket they ran like a champ. There's just some passages in carbs that you can't get clean enough without it.

+1 on this.
 
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Gas Pig

Gas Pig

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Ok I pull the carb again and give it good bath. Apart from that it has to be the issue because everything seems to check out ok.

Thanks and I'll report back with the results. Jeff
 
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Gas Pig

Gas Pig

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Update: all good now! I took the carb off then apart and didn't see any new junk in the bowl but still was going to clean it. I got a small catch container then soaked and blasted the carb with carb cleaner in every port I could find. I did this three times and by the 3rd time I could see noticeably see carb cleaner freely flowing through ever port. In my container you could see very fine junk in the used carb cleaner. So I put the carb back together and reinstalled it. She fired right up... idled and ran great! Also for safe measures I installed a new stock style fuel filter back on the carb.

Thanks to all for helping a bronco get back on the road! :)
 
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