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Hey i just bought an 81 bronco for $1500. The previous owner put a new carb on it and new cap and plugs. When the thing is warmed up it runs great but in the cold it will always die after first crank and 2nd crank I have to keep the rpms around 4k just so the things stays running. When its finally warming up its smooth. I feel like im dumping a gallon of gas just to start this thing. Also sometimes I'll shift into drive and the truck acts like its still in park. I'm definitely a newb bronco owner and a newb with non fuel injected engine. Any advice?

1981 Bronco XLT
351 auto
182k miles
 

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Probably needs carb choke work for the cold crankiness.

There’s a seal in the tranny that leaks cold but will seal when warmed up. I’m not intimately familiar with it, but you can google “C6 morning sickness” and get info on it.
 

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Ahhh... Welcome to my world! Been going thru this with my 82 since the beginning of summer and since replacing... Carb (went to Edelbrock 1406), starter, starter solenoid, all wires and ground between the battery, solenoid, starter, and alternator, and changed to a universal gm ignition (getting rid of the highly cantankerous EECIII system) distributor ect and reset timing only to STILL have a cold start/long crank issue we finally figured out it was the auto choke. It wasn't opening up so it was starved for fuel. Almost like there was a backflow issue when it would sit for a couple days... It's at the mechanics right now being fine tuned... I'll let Cha know how it goes 👍
 

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What did the original owner replace the carb with? Any idea?
 

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Discussion Starter #5
Yeah im thinking its gotta be a choke issue. Seriously I don't care how cold it is it fires right up... Just right after it dies no matter how much you pump the gas. How do I adjust that? ELIF?
 

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Yo 81gdad,
WELCOME!
For any Bronco questions or to chat about it's planned modifications or build, it's better to post each seperately in Noobie Bronco Tech Questions. Flame free zone. This will get more attention and you can build up your post count to get into other sections such as Bronco and Ford Parts/Accessories (75 posts required to view).

To save you time and for better responses, please fill out your Signature with location, year, engine size, transmission type, transfer case type (manual or electric shift), locking hub type (automatic or manual) info & major mods such as a Lift, etc. .
From the navigation, near the upper right-hand corner, click on your avatar and then select “Account Settings” from the drop down menu.


From your “Account Settings” page you will then see more navigation option of the left side. Select “Signature”.


Now you can simply enter your signature information in the text editor and click save.

Our Forum faqs @ https://www.fullsizebronco.com/help/faq/
Includes for example:
How To Upload Images To Posts & How to Use Search
See more tips!

There's only three Technical Service Bulletin for the 81 @ http://www.bbbind.com/tsb-wiring-diagrams-database/
LABOR TIME STANDARDS - MCU AND EEC REVISED ALLOWANCES
TSBID: 103975 ,MFG NUMBER: 87-15-14 ISSUE DATE: 1987-06-01T00:00:00
LABOR TIME STANDARDS - USE OF OIL LEAK DIAGNOSIS OPERATIONS
TSBID: 103957 MFG NUMBER: 87-5-19 ISSUE DATE: 1987-01-01T00:00:00
REVISED SERVICE LABOR TIME STANDARDS
TSBID: 103962 MFG NUMBER: 87-8-20 ISSUE DATE: 1984-05-03T00:00:00

Baba Looey's Favorite FSB Links (lots and lots of tech links) @ https://www.fullsizebronco.com/forum/21-noobie-bronco-tech-questions-flame-free-zone/131287-baba-looeys-favorite-fsb-links-lots-lots-tech-links.html
Includes good stuff such as Tailgate Tech!

1981 Bronco Dealer Brochure by Gary @ 1981 Bronco Brochure - Gary's Garagemahal (the Bullnose bible)

1980-1986 Bronco/F Series Fasteners by Gary

1980-1986 Bronco/F Series Carburetors, Chokes & EFI by Gary

1980-1986 Bronco/F Series Specifications by Gary @ Axle Ratios - Gary's Garagemahal (the Bullnose bible)

Differences in 1980-1986 Bronco/F Series by Gary

1981 Bronco/F Series Electrical & Vacuum Troubleshooting Manual (EVTM), partial via Gary @ 1981 EVTM - Gary's Garagemahal (the Bullnose bible)

Partial Chilton Manual for 1978, 1979, 1980, 1981 Bronco. Scanned by broncocity.com @ https://web.archive.org/web/20130419152159/http://www.broncocity.com/66-81manual.htm

1981 Bronco Advertisement @ Ads0002.jpg


EEC III Testing, etc @ http://web.archive.org/web/20101222172609/http://home.comcast.net/~TommySpace/EEC3.html by Tommy

Find some time to participate and VOTE in our Full-Size of the Month (F.O.T.M.) & Full-Size of the Year (F.O.T.Y.) Contests @ https://www.fullsizebronco.com/forum/27-f-o-t-m-voting/
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Vote for the ongoing Full-Size of the Year (F.O.T.Y.)!
Al
 

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Discussion Starter #7
Thanks for the responses and the info. So the electronic choke is the problem as the wire is not hooked up its just wrapped around a battery cable. It's got a new motorcraft carb the previous owner installed before the transmission cooler started leaking which at that point he decided to sell as it was too much of a project for him. So now im try g to figure out where this wire goes
 

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Figured it would be the choke... A bit of advice from another thread regarding wiring the choke...
Screenshot_2019-11-01-22-05-41.png
 

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I'm not sure if this applies to the motorcraft as well as the Edelbrock. Hopefully someone smarter then me chimes in to confirm if running the new wire is worth it.
 

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Yes, all electric chokes work the same.

I tear them off and put a manual choke on mine so it does what I want when I want it to. I’ve never been able to get an electric choke to work well for me throughout the seasons here.


Sent from my iPhone using Tapatalk Pro
 

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Stupid question but how does a manual choke work @biggum is there a switch or something u installed inside cab?
 

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Discussion Starter #12
Well shouldn't the motorcraft be the stock replacement? If so I should be able to run it directly to the stater like the oem was.
 

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Yo 81,
Do you have EEC III system with the Electronic Control Assembly (ECA) under passenger's seat? See attached ECA component location depictions from 1981 Bronco/F Series EVTM @ http://www.garysgaragemahal.com/1981-evtm.html
150048


150049

Charge & Power Distribution, page 16;
"The choke heater operates only when the alternator is generating current through terminal s (miesk5 note, that is the stator with yellow wire with white dots) .
Above 60 degrees temperature the heater cause a thermostatic spring to pull the choke open within 1 to 1.5 minutes.
Below 60 degrees F, the heater does not operate and normal choke opeeation occurs"

HOWEVER, see attached for full 12 volts DC.
150047

Now we need more members to chime in.

■□■
For posterity, from our ex 76 F notes;
"The stator "Y" connection, on the back of the alternator, is the correct point of connection for a factory electric choke. It provides around 7 volts. Stator terminal is usually marked "stator" on the case.
A 12 volt source is needed for aftermarket carbs to work properly."
 
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