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I have a 1981 351M automatic I am having troubles with. I have learned from YouTube and colleges from the part store I work at. I have done all the work myself as far as seal replacements, gaskets, axle shaft, valve cover...the simple things. I am now trying to pass an emissions test here in Denver, CO. The vacuum lines are a complete mess and I believe I finally have them all routed to their proper locations. However the curse of "fix one, two more go down," has happened so many times. Now the smog or air pump is making an awful ticking noise I can't seem to fix. There is still airflow from the output. The diverter that is connected on top does not provide airflow. So I believe I have found one fault in the system so far. I then noticed the mark on the mounting bracket and tried to put it back where it once was, maybe that will help? I then continued my adjustment with the idler screw and fuel ratio screw. Perhaps my adjustments hurt something? I do not know. This is the first vehicle I've worked on, and I plan on doing a complete restoration. No crazy mods, nothing crazy expensive or eye catching. To me original is truly eye catching and more desirable. I need some help with this beast. Routing diagrams, tips, good places to purchase replacements, links. Anything to help me with all troubles. Chassis wiring. Interior wiring. Suspension. Mounts. Body adjustment specs.
Now, for the pictures. Is this thing supposed to have one or two vap canisters? Proper routing? I have tried a few different ways but nothing I am completely satisfied with.

The carburators float seems to be rather stuck at first. When the engine is cold the flap is not able to close without being pushed manually. Is the valve I believe it's called the cause of this?

I have capped a few ports trying help the air to fuel ratio. So far I don't believe I've hurt anything further. However it still feels as though I have not helped anything either.

The smog or air pump makes a wicked ticking noise. What is the cause of this? I've removed the diverter valve to check the output. Diverter is definitely faulty. No air being pushed out of it.

The kickdown linkage bar seems to be extremely loose. As a matter of fact I have no kickdown when putting the pedal to the floor. Quite recently it has been hesitation to keep going or even staying on instead. Hence my new research towards the smog.

I was given the advice to cap my oil filler. Is this smart to do? I am under the impression these things had to breathe.

Need some help here please! Greatly appreciated.
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I have a 1981 351M automatic I am having troubles with. I have learned from YouTube and colleges from the part store I work at. I have done all the work myself as far as seal replacements, gaskets, axle shaft, valve cover...the simple things. I am now trying to pass an emissions test here in Denver, CO. The vacuum lines are a complete mess and I believe I finally have them all routed to their proper locations. However the curse of "fix one, two more go down," has happened so many times. Now the smog or air pump is making an awful ticking noise I can't seem to fix. There is still airflow from the output. The diverter that is connected on top does not provide airflow. So I believe I have found one fault in the system so far. I then noticed the mark on the mounting bracket and tried to put it back where it once was, maybe that will help? I then continued my adjustment with the idler screw and fuel ratio screw. Perhaps my adjustments hurt something? I do not know. This is the first vehicle I've worked on, and I plan on doing a complete restoration. No crazy mods, nothing crazy expensive or eye catching. To me original is truly eye catching and more desirable. I need some help with this beast. Routing diagrams, tips, good places to purchase replacements, links. Anything to help me with all troubles. Chassis wiring. Interior wiring. Suspension. Mounts. Body adjustment specs.
Now, for the pictures. Is this thing supposed to have one or two vap canisters? Proper routing? I have tried a few different ways but nothing I am completely satisfied with.

The carburators float seems to be rather stuck at first. When the engine is cold the flap is not able to close without being pushed manually. Is the valve I believe it's called the cause of this?

I have capped a few ports trying help the air to fuel ratio. So far I don't believe I've hurt anything further. However it still feels as though I have not helped anything either.

The smog or air pump makes a wicked ticking noise. What is the cause of this? I've removed the diverter valve to check the output. Diverter is definitely faulty. No air being pushed out of it.

The kickdown linkage bar seems to be extremely loose. As a matter of fact I have no kickdown when putting the pedal to the floor. Quite recently it has been hesitation to keep going or even staying on instead. Hence my new research towards the smog.

I was given the advice to cap my oil filler. Is this smart to do? I am under the impression these things had to breathe.

Need some help here please! Greatly appreciated. View attachment 196291
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Wow so much to reply to… first thing that jumped out to me was your carburetor float question… you can’t see your floats, they are internal to your carburetor, so how have you dertimind they are sticking. A sticking float will cause either fuel starvation, or fuel spilling out the float bowl. The top butterfly you describe is your electric choke, not the float. The choke starts off closed, and gradually opens up as the thermostat warms up.

going through your pictures in order.

picture 1 is your air injection pump belt tensioner. This adjusts the belt tension but will probably have little to no effect on the ticking sound you hear coming from the pump. Ticking from the pump indicates it is on its way out. With the belt removed spin the pulley while feeling for excessive play (sticky spots will be normal as the pump builds compression).

picture 2 high idle solenoid for the AC system.

Picture 3 Choke Butterfly. The shaft that holds the butterfly has a black plastic disk attached to one end… this is the electric Choke Thermostat. It gets power from the positive side of the ignition coil.

Picture 4 is the PCV Valve. It’s function is to maintain a constant pressure inside the crankcase. (Over simplified

Picture 5 is the air pump and air diverted valve.

Picture 6 carbon canister (often referred to as the charcoal canister because it’s filled with charcoal like substance). The fuel tank vents to the canister to store the evaporated fuel fumes to be burnt when the engine is running.

Buy a Haynes or Chiltons manual for your bronco (personally I have both) the manual will help you a lot as you learn to work on your rig.
 

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Yo FrankenBronco81,
Welcome to our Big Bronco DIY site!

Here's some information for you:
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1981 Bronco Brochure - Gary's Garagemahal (the Bullnose bible) by Gary

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)

1980/1981 Light Truck Roadability Diagnosis Guide @ 1980 Light Truck Roadability Diagnosis Guide

EEC III Testing, if not removed or disabled by a previous owner or shop via Wayback Machine by Tommy

Haynes Red Manual for 80-95 Bronco & F Series @ Hanes guide 80-96 bko f series.pdf via BroncMom!

Partial Chilton Manual for 1978, 1979, 1980, 1981 Bronco. Scanned by broncocity.com @ Bronco City

1981 Bronco Advertisement @ Ads0002.jpg

Baba Looey's Favorite FSB Links (lots and lots of tech links)
Includes good stuff such as Tailgate Tech!

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 that requires 50 non- padded posts to buy or sell due to scammers who preyed on our members.

See How to add your 81s Signature @ Bronco Forum - Full Size Ford Bronco Forum by BigBlue 94

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