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New User - 83 Bronco - 300 straight 6, 4 speed manual

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Gary Lewis

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

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The first pic shows a DS-II ignition module. And if I remember correctly the feedback carbs got the TFI ignition. Right, Matt?

But maybe we need a better shot of the carb with the air cleaner off.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

FuzzFace2

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

In reply to this post by Brock

Brock, how bout a better picture of the dist. and dose it have a vacuum hose going to it?
Also when looking at the firewall just to the right, when looking from the front of the back of the motor / valve cover area, is there a bunch of wires going into the cab there?

From what I now see from the pictures as Matt said it dose look like a feed back carb BUT.....
The 1 picture of the dist. looks like it has a vacuum can on it and a hose going to it then the IGN. DSII box on the inner fender looks like its been there for a long time, factory?

I wounder if this was a feed back system that has only been have done to remove?
Or it needed a carb and a used feed back carb was installed?

I think the 83 year was when the feed back system was coming into play.
What is the date on the door sticker, month & year?
My 81 F100 has a date of 11/80, anything built after Sept. is the following year my case 1981 model.
Dave ----

Edit I also wonder if the motor has been changed out at some point?
I ask because of the oil dip stick being so long like from a van?Mine is shorter but I am sure my motor came from a car as the exh manifold would not take a truck head pipe and why I went with EFI manifolds.

Dave G.
81 F100 flare side 300 six / AA OD / NP435 / 2.75 gear
http://cars.grantskingdom1.com/index.php/1980-Ford-F100?page=1
81 F100 style side 300 six/SROD parts truck -RIP
http://cars.grantskingdom1.com/index.php/1981-Ford-F100

Brock

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

FuzzFace2 - This engine had been swapped from a pickup truck and I do know that the carb is not original from this Bronco. My dad had told me that the previous carb ran better. So, it sounds like I may need to run a check on the engine to find out what engine year is in there. I will look for the engine nameplate or something, not sure where it is though. If I found that information that would probably tell us what type of distributor is there. Would that then be enough information to make sure I can find the correct carb?

FuzzFace2

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

Brock wrote

FuzzFace2 - This engine had been swapped from a pickup truck and I do know that the carb is not original from this Bronco. My dad had told me that the previous carb ran better. So, it sounds like I may need to run a check on the engine to find out what engine year is in there. I will look for the engine nameplate or something, not sure where it is though. If I found that information that would probably tell us what type of distributor is there. Would that then be enough information to make sure I can find the correct carb?

I dont think you will find anything on the engine on what it is or from.

On the dist. just take a better picture of it and if it has a vacuum hose going to it.
I think the dist. dose have a vacuum hose and the truck has the DSII box on the inner fender.
I also think the carb is a feed back from something else.

If that is the case and if the carb is not working right it might be best to replace it with a non-feed back one than try and rebuild it. With non-feed back parts installed we can then help you tune it, feed back system a computer dose the tuning.
Dave ----

Brock

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

This post was updated on .

Here are some more pictures. I found that likely the distributor was from this 83 Bronco, but the carb was from an 82 F150 (which that is also the engine that is installed). I found that there is a vacuum line running to the carb from the distributor (module just below it)

Gary Lewis

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

Administrator

I believe you have a "hybrid". I see a connection dangling on the carb that is probably for the feedback system, but I'll let others more familiar with those carbs confirm that. However the distributor is for sure from a DS-II system.

So if, as I think, you have a feedback carb and a non-feedback ignition then the question becomes what to do. If you also have a computer then the computer isn't going to be happy 'cause it isn't controlling the ignition. But there's not much it can do about that save for changing the air/fuel ratio via the carb, and it has a very limited range in which it can do that. Maybe not even enough to cause problems.

Given that I'd say you would be best to go with a non-feedback carb.

Gary, AKA "Gary fellow": Profile

mat in tn

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

I have been reading up on this this morning and going back and reviewing the pics as I get the points that others have been pointing out. wow! this is either a factory transitional hybrid like a mid-year production change or a very interesting Frankenstein. it is a feedback carb but the stepper motor is not hooked up. not really an issue as it is mostly for adjusting to the load of the ac system which is nonexistent. there is no tps for the ecu to read so that is interesting. the feedback solenoid does seem to be hooked up electrically but it's not the focus of the picture so I could have that incorrect. the dipstick length is not really significant aside from it being the length of a van model and seems to be welded to a bracket for stabilizing a dealer air compressor bracket. as far as whether it "could run well or not, I don't see any reason why it could not. If the feedback solenoid were not open it would just not have the lean circuit option. if the dist. is a stand-alone only reading vac signal, then it won't know or care what carb it has. that just means the tuning is all "back to basics".

Gary Lewis

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

Administrator

Since Brock said "I found that likely the distributor was from this 83 Bronco, but the carb was from an 82 F150 (which that is also the engine that is installed)" I think we can rule out it having come from the factory this way.

But you are right, it might run well if tuned correctly. However, Brock started the thread asking for what carb he should buy, and right now I'd say he should buy one of the cheap Chinese YF knockoffs as it would stand a good chance of being set up right for this truck. More so than the feedback carb.

Gary, AKA "Gary fellow": Profile

mat in tn

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

maybe so. i just hate that we have gotten to the point of believing a "cheap Chinese" anything is the answer. feels like giving up to me. Can I get an amen?
certainly, we have a rebuilder among us who may have a good yf on the shelf. I only have a yfa and its modified or I would make it available.
on second thought I just removed the exact drivetrain he should have from my newest project lefty. carb has not been rebuilt or even run-in years but that may be an option.

Gary Lewis

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

Administrator

Yes, it is odd to think a "cheap Chinese" carb can solve a problem. But it really can as several others have had success with them.

However, if you have the right one...

Gary, AKA "Gary fellow": Profile

FuzzFace2

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

In reply to this post by mat in tn

mat in tn wrote

maybe so. i just hate that we have gotten to the point of believing a "cheap Chinese" anything is the answer. feels like giving up to me. Can I get an amen?
certainly, we have a rebuilder among us who may have a good yf on the shelf. I only have a yfa and its modified or I would make it available.
on second thought I just removed the exact drivetrain he should have from my newest project lefty. carb has not been rebuilt or even run-in years but that may be an option.

I am a little late coming back to the party

The real issue with the feed back system is not the 2 big items, carb & dist. but all the little things that make the computer happy and to let it make adjustments as needed.

Have just 1 of the 3 relays / valves on the valve cover go bad and the system goes in to "limp mode".
Now try and find the needed part and you can get a lot older before you find one and it will most likely be used and who knows if it works?

That is why if there is no smog check to just scrap the feed back system and go old school carb & dist.
Dave ----

Brock

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

In reply to this post by Gary Lewis

So I think I’ll get a single barrel carb with non-feedback. I just need to choose either climatic choke or electric choke. I’ll probably get one from the National Carb site below.

https://nationalcarburetors.com/ford-trucks_c_292.html_6-cylinder-1-barrel-carburetor_1982

Could anyone recommend one on that webpage?

At the moment I have a manual choke but it would be nice to have it be automatic.

I thought about going 2bbl with an adapter but I don’t want to overkill this.

Gary Lewis

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

Administrator

Personally I'd go with the electric choke as it is probable that your hot air tube is rusted off, which is why someone converted to manual choke. The electric choke isn't quite as good at determining the temp of the engine so doesn't get the choke "right" in as many cases as the climatic choke, but it works pretty well.

An example of that is in restarting the truck in cold weather when the engine is still warm. The carburetor will cool faster than the exhaust manifold due to the amount of metal in each. So when you restart the electric choke will dial in more choke than the climatic one will. But it still will work.

So I'd go with ND1506.

Gary, AKA "Gary fellow": Profile

Brock

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

I removed the old carb. I wonder if part of the rough starting and idle problem was exacerbated by possible vacuum leak? I could jiggle the carb before I remove it. It seemed loose. Here is a picture of the intake after the carb was removed.

mat in tn

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

loose carb bolt/nuts is actually in some of the service manuals as a possible cause for rough idle/poor performance.
as a unique part of the ford 4.9 . the yf carb is also known for the carb base plate screws coming loose and causing a vacuum leak within the carb. while you have it off check those also. they should be a number 3 Phillips but I seem to remember some torx headed ones too

FuzzFace2

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

Yep the carbs like to come loose
I think I would have tighten it up to see if that fixed it and gone from there as it could save you some coin.
Dave ----

Brock

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

Well I installed the new non feedback YFA electric choke carb and reconnected everything except the electric. I’m wondering which wire from the truck to connect to the electric choke? See the image below. Any suggestions? I tried the single white ended connection but when I started it the rpms ramped up really fast and then it died. Once I make the correct wire connection, the fun begins adjusting the carb - I’ve never done that.

Gary Lewis

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

Administrator

I'm guessing that the reason the RPM's went up is that the fast idle kicked in, which is exactly what it should do. The fast idle RPM is adjustable, so that's not a big worry. And it may have died because the choke didn't come off very fast.

There are two ways to hook up a full-electric choke:

Quick & Dirty: The white/black wire (white with a black stripe) comes from the alternator's stator circuit and supplies ~7 volts. This can be used to heat the choke but it will take a lot longer than full battery voltage. I've used it and it works fairly well.

Proper Way: Ford used a relay, as shown below from the '85 EVTM, to power a full electric choke. The relay gets its power from the always-hot terminal of the starter relay and is pulled in by that white/black wire from the alternator.

If you don't mind doing some wiring then go for the relay. But if you just want to get it on the road for a test use the wire from the alternator. It won't pull the choke off nearly as fast as battery voltage, so you'll have to adjust the choke some.

Gary, AKA "Gary fellow": Profile

Brock

Re: New User - 83 Bronco - 300 straight 6, 4 speed manual

Thanks for the advice. I got out the voltmeter and found that one of the female spade connections in the connector coming from the distributor/ignition had ~12 V (only when the key was on) so I just wired that to the electric choke. When it warmed up, the choke opened so I think the choke is working.

I was able to make adjustments to this new YFA electric choke 1 bbl non-feedback carb but I still have a problem. I adjusted the idle mixture screw, curb idle screw and fast idle screw. There was a surging up and down in the rpm's every few seconds during idle and so the only adjustment I could make to fix that was to screw the curb idle screw in ,mashing the spring down (a bit more than seemed appropriate to me). The idle mixture screw didn't seem to cause much change when I adjusted it.
I think I screwed the curb idle in too far because when I went for a (very short) drive, I put it in first gear and I didn't need to push the throttle to move, it did it on its own, the throttle almost seems too responsive.

Any ideas on how I should proceed? I'd like to reference a document that could illustrate what vacuum hoses need connected and to where. Does anyone know of one? There are several factor plugged ports on the carb that I'm not using. Thanks in advance for the help!