Choke Question, what would you do?

[FuzzFace2]

My 81 F100 with a 300 six, factory Carter v1 carb and EFI exh manifolds and the manifold may be where the issue lies? The intake had a hot water plate to heat the intake / carb.

I have used the truck last few days to work and is has gotten cold, this morning it was 28*f when I left at 3am. I am finding at 45* or lower the choke will not pull off all the way and the fast idle stays on and the AFR gauge stuck on 10, the highest rich reading. The truck runs great other wise and above 45* the choke pulls off as it should.

I pulled the below information from here so you know how Ford wanted the choke to work.

Hot Air w/Electric Assist: The 1981 factory shop manual says this: "The hot air choke with the electric assist choke cap functions as follows: as the engine warms up, manifold heat transmitted by hot air to the choke housing relaxes the bimetal permitting the choke to open. The electric assist has a ceramic heating pill. At temperatures above 12 degrees C (54 degrees F) to 23 degrees C (74 degrees F), the temperature sensing switch closes and current is supplied to the heater causing the bimetal to pull the choke plate open at an increased rate. The electric assist choke cap is powered from the stator tap of the alternator."

Now for them EFI EXH manifolds that I think might be where the problem lies.
The stock log manifold had the "hot air tube" my fix for that was to wrap copper tubing around 1 of the tubes. I wonder if I may not have made enough wraps of the copper to pick up heat?
I think (need to re-check) that I used the white insulation sleve on the hot side.

So is it not enough heat from the "hot air tube" or something else?
I will be leaning out the choke a little so I can drive it when below 45*
Dave ----

[85lebaront2]

Dave, you could put a completely electric choke thermostat on it, then it would warm at a fixed rate. If you can find a water heated choke cover, like Pintos used and make it fit, then it would be tied to engine warm up.

[Gary Lewis]

Bill - That's a good idea.  Here's a link to Mike's where he lists several choke stoves, so Dave would just have to get the right one.  

But, I found something else.  Some folks on a forum about a car line called AMC, whatever that is, were talking about a Carter YF electric choke conversion.  Anybody heard of an AMC?  

[85lebaront2]

Yeah, I think they were formed from Hudson and Nash (trivia item, cast on the Gen 1 AMC V8 heads are the joined letters HN for Hudson Nash)

[Gary Lewis]

Didn't know that.

Anyway, an electric choke would be easy.  But the hot-water Pinto choke would be ... cool?  What carb did they have and will the choke cap/stove fit a YF/YFA?

[FuzzFace2]

Happy turkey day everyone

Thanks guys but I dont know what a AMC is

I dont really want to use a full 12 volt cap as I would need to run a wire from power with key on and as said on that AMC link should run through something so the choke is not powered up if not running like a oil pressure switch that is more work also.

What I did pick up from that AMC site if you could not run tubing like the factory, through the manifold, was to wrap copper around the manifold like I did. This leads me to think I need to do more wraps to pick up more heat and make sure the hot side is insulated.

On the hot water cap I was also thinking of the bracket Ford used on v8 motors that held the heater hose to the choke cap to help it heat up. But I would need to run more heater hoses. I have a heater core bypass valve installed and the intake heater so have more hoses down there now.

I also think that low heat is the issue because the choke would almost open when stop at lights for a bit but if driving and then came to a light the choke would be back on, fast idle. I think the cold air blowing through the engine bay would cool the heat side of the copper tubing.
I also dont have any protection covering the copper on the manifold and that may help trap heat.


I have some home work to do to see what would be the easiest (I am lazy but also want it to look factory) way to get this choke to work like it should.
Thanks
Dave ----

[Gary Lewis]

I suspect you are right that the air is cooling the tubing.  So if you can insulate the hot side it might help.

[85lebaront2]

AMC = American Motors Corporation, merged with or acquired by Renault, split from Renaualt and taken over by Chrysler, who in turn went through a number of ownership changes, Cerebus Capital, a merger with Daimler-Benz, dissolved and acquired/merged with Fiat to become Fiat Chrysler Automobiles.

FCA was recently merged with PSA (Peugeot and Renault) to become Stellantis. Headquartered in Italy, brands include Alfa-Romeo, Fiat, Ferrari, Maseratti, Renault, Peugeot, Chrysler, Dodge, Jeep, Ram and a few others.

[FuzzFace2]

85lebaront2 wrote

AMC = American Motors Corporation, merged with or acquired by Renault, split from Renaualt and taken over by Chrysler, who in turn went through a number of ownership changes, Cerebus Capital, a merger with Daimler-Benz, dissolved and acquired/merged with Fiat to become Fiat Chrysler Automobiles.

FCA was recently merged with PSA (Peugeot and Renault) to become Stellantis. Headquartered in Italy, brands include Alfa-Romeo, Fiat, Ferrari, Maseratti, Renault, Peugeot, Chrysler, Dodge, Jeep, Ram and a few others.

Bill, it was a joke as I know of AMC as I have been into them for a long time. I have 2 1970 Javelins, 1/4 mile drag car and a car I have been re-building for the street I have had for over 30 years now.
I also have a 1975 Gremlin factory v8 auto and a bunch of parts I have picked up over the years.

When Chrysler bought AMC back in 1988 they did it for the Jeep side and got rid of anything else AMC including all parts as they were crushed
It was a sad day for us AMC fans.

It might be warm enough, 45* from 27* to go look at this choke issue and maybe the trailer hitch so I can get the spare tire mounted.
Dave ----

[jdavidsmi]

I thought everyone has a AMC car hidden back in their history.
 We had a Pacer in the 70s, kept having issues with wiring harness melting and the car would just die. It was in the shop as much as it was drivable. After 3 months, Traded it in on a Chev Malibu wagon .

Sorry for the hi jack, still cringe when I think about it.

[LARIAT 85]

Yes, I think your problem is not enough heat getting to the choke cap.

You can purchase a hot air choke stove from most auto parts stores for about $10:

https://www.napaonline.com/en/p/NOE6101116?cid=paidsearch_shopping_dcoe_google&campaign=GSC-Fuel-Emissions&campaign_id=10951730297&adgroup_id=113117085528&adtype=pla&gclid=Cj0KCQiAhf2MBhDNARIsAKXU5GQBP1pMnk78xl_Riq-JyPcbi76M-0VHJQ2s9icQCfE4-ABg--VITT8aAlMGEALw_wcB&gclsrc=aw.ds&

The universal Choke Stove Kit is designed to bypass the choke stove chamber on the exhaust manifold and replace the stock choke tubes completely. The kit comes with a length of coiled up aluminum tubing that you can easily bend by hand, the tubing insulation, the hardware to mount the tube to the choke cap, and a little "dome" with a hole in one end for the tubing to push into. This dome clamps to the exhaust manifold or header pipe to trap the hot air when the engine is running and routes the hot air up to the choke cap.

The factory setup had a "fresh air" tube that routed from the carburetor air horn down to the bottom of the choke stove chamber on the exhaust manifold. This location provided filtered air because this area is located on the "filtered air" side of the air filter once the air cleaner is in place. But the universal Choke Stove Kit doesn't use the "fresh air" portion of the hot air choke at all. So I drilled a second hole on the other end of the dome that came in the Choke Stove Kit so that the hot air going into the choke cap would be filtered, more like how it originally done by Ford. You can see where mine attaches to the carburetor air horn by the rubber hose right behind the choke cap.

[85lebaront2]

We never owned any AMC cars, one of our neighbors in Norfolk VA had a Hudson, and another had a string of Packards. AMCs biggest problem was always money, they had some excellent cars, but had to outsource a lot of components Ford and GM manufacture or own plants as subsidiaries to build components, electrical and fuel systems in addition to transmissions. The independents, AMC, Studebaker-Packard, Kaiser-Frazier had to either buy from Ford or GM or share a supplier. GM owns AC Delco, Packard Wire and Cable (after Packard's demise) Rochester Carburetor. Ford Owns Motorcraft. Both Ford and GM built their own carburetor and electrical parts along with transmissions and axles. Chrysler bought electrical and carburetors from outside sources, Autolite or Delco electrical, Carter, Stromberg and Holley for carburetors, Studebaker used Stromberg and Carter, Packard used Autolite or Delco electrical and Carter or Rochester carbs AMC, used all of those sources except Stromberg carbs. Packard was the only independent to develop their own automatic transmission in house, part of which still lives on in the lock-up torque converters. Studebaker used a Detroit Gear, later Borg-Warner transmission with a lock-up converter also.

Stellantis seems committed to bringing at least what's left back to the living. FCA revived a couple of AMC names, there was a Dodge Ram Rebel model, reviving the 1957 Rambler Rebel name, supposedly the Hornet name is returning.

On the Pacer, maybe the very name was cursed, it was an Edsel model in 1958. Ford retained two of the model names, Ranger and Corsair, Citation was also apparently cursed, Ranger has done well as a small truck, Corsair supposedly is returning as a Lincoln model

[Gary Lewis]

Our Chevy Citation had more recall badges than places to put them.  They ran from one fender to the other across the radiator support.  

[JimsRebel]

You can use a full 12 volt choke cap and wire it to the stator output, it just takes about a minute longer to open the choke fully. I did some bench testing of different choke caps with both 6 and 12 volts applied to them, as I was considering going this route.
It is by far the simplest fix.
Jim

[Gary Lewis]

I agree.  I've run a 12V Edelbrock choke that way.

[mat in tn]

i get the copper coil wrapped around the manifold. its basically the same thing . i wonder about air flow through the tubing. is the tubing just open at the end or is it crimped nearly shut? depending on how open the air feed is at the carb you may not be actually bringing heat to it unless the contents of the tube can actually soak up enough.

[Gary Lewis]

Hopefully he set it up the factory way with the cold end connected such that it pulls filtered air from the air cleaner, as shown below for the 2bbl.

Dave - If you want more or different insulation you might try this ThermaShield Wrap.  I'm using it on Big Blue's dip stick.

[FuzzFace2]

JimsRebel wrote

You can use a full 12 volt choke cap and wire it to the stator output, it just takes about a minute longer to open the choke fully. I did some bench testing of different choke caps with both 6 and 12 volts applied to them, as I was considering going this route.
It is by far the simplest fix.
Jim

I was wondering if I could use a 12 volt cap and what would happen now I know just opens slower.

But that brings up something else. The way the factory cap works is it does not do anything till the temp is 70* or more to help open the choke faster.
Where is this temp switch? Or dose it get this 70* from the hot air and then opens faster?
If I was to put on a 12v cap other than it opening slower because it is only getting 6 to 7 volts would this temp switch also play into it?

mat in tn wrote

i get the copper coil wrapped around the manifold. its basically the same thing . i wonder about air flow through the tubing. is the tubing just open at the end or is it crimped nearly shut? depending on how open the air feed is at the carb you may not be actually bringing heat to it unless the contents of the tube can actually soak up enough.

Hopefully he set it up the factory way with the cold end connected such that it pulls filtered air from the air cleaner, as shown below for the 2bbl.

Dave - If you want more or different insulation you might try this ThermaShield Wrap.  I'm using it on Big Blue's dip stick.

To answer Mat & Gary:
The hot air tubing is run just like the factory had it.
Fresh clean air is pulled from the factory spot.

It is wide open on both ends and no kinks to hinder air flow with in the tubing.
It runs down to the manifold and makes think its 4 wraps. When I checked the other day it is a little neater where all the wraps are on the manifold and not other each other like in the picture.

You can just make out the insulating sleve on the hot air side going up to the carb in the above picture and here into the carb.

So other than the tubing being wrapped around the manifold it is run just like the factory.
Bill, I did buy that kit. Dorman makes one and I used the sleve from it. I did not want to have it pull "dirty" air if I used that metal half bucket thing and why I went with the wrapping.

So yesterday I leaned the choke out a little, did this after I marked the cap & housing so I know where I started.
I also checked if the hot air tube is getting heat and it is it just took some time for the heat to make it to the carb choke area.
I think I am going to try and add a few more loops around the manifold to get more heat to see if that helps any.

I took the truck to work again today and the choke door seams like it can use a choke pull off as the carb dose not have one. other wise going a little lean did help but it was also about 45* where it would work ok so I have more testing & tuning to do.

Also when I went to leave work I checked the snorkel flap to see if it was open to pull heated air from the manifold area, every little bit should help right?
The door was closed. The air filter has 2 temp switches and I got the wrong one hooked to the flapper.
The hoses are to short or I would have swapped them so I need to swap the switches.

If I can get the flapper working I can add a hose to it and poke it down close to the manifold to pickup heat as I think the cold air coming into the carb is also keeping the choke cool and not opening.
Right now fresh air is 100% from in front of the grille to the carb.

As we know carbs always need tinkering to get them just right.
Thanks for the help
Dave ----

[85lebaront2]

Get some header wrap and put it over the tube area where it goes around the manifold. One of the issues is that the choke stove as it is called, is it is either part of the manifold (300 and the older Windsor engines) or inserted into the exhaust passage (most V8s and some V6s). The ones integral with the manifold depend on the entire manifold getting hot, actually red hot on the highway and the internal ones are thin stainless steel tubing, sometimes with a piece of stainless steel wool or a spiral to (a) slow the flow down a bit and (b) expose more area to heat the air.

On some older Ford V8s it was a stainless steel tube that was larger in one end than the other and was pressed in, Chevrolet used a similar design. main difference was location, Ford Y-blocks had it in the crossover, Chevrolet in the right side exhaust manifold.

I had a big Ford V8, an MEL 430 that had a water heated choke on a big Carter AFB. The early versions had a choke stove in the right exhaust manifold.

[FuzzFace2]

Never gave it a thought of header wrap  to help hold in the heat.
I think between the wrap & more tubing loops may do the job.

You are right that the tube should be in the path of the hot gases from the factory on the 300.
Because I am running the EFI manifolds it does not have a choke heat tube passing through it so I came up with the copper wrapped around the outside.
 
I cant remember if I ever had the truck out being as cold as it was, 28*f, the other day and why I think this has come up now and not before.

My Street AMC Javelin has it in the intake cross over and seams to work pretty good there.
Little by little I will get the choke dialed in on the truck.
Dave ----