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4V Choke electrical voltage

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BigBrother-84

Re: 4V Choke electrical voltage

Capiche, thanks Jim.

Now, let's dig little further with the choke voltage question... Here are some picts I took of the old and new carbs.

Three questions:

1- Caps voltage:

Gary Lewis wrote

But the real question is what the black plastic choke heater says. 12V?

Well, there is no such indication on the two caps. Do I look correctly?:

2- Caps swapping:

85lebaront2 wrote

Why not just use the Holley choke cover for the 4180? It is made for the 7V supply.

I canot figure out how the old one could fit on the new carb... Maybe I suffer of a lack of creativity?
And the new one appears to be much easier to adjust... I am wondering how to adjust the old model? Never done it...

3- Relay solution:

Whisler wrote

The relay setup works well on the Edelbrock on my 351W, pulled in by the stator wire.

Could a relay add-on be a simpler solution? If so, any suggestion about such a relay and how to wire it?

Thanks again Gentlemen!

Jeff / 1984 F350 Crew Cab 4x4/5.8L w351 4V/ T18/ D50 4.10 front/ 8' bed.
Restored 2019-2022.
Nicknamed «Big Brother 1984», due to its soooo-looong shape & nod to George Orwell's 1984 famous novel.

ArdWrknTrk

Re: 4V Choke electrical voltage

Administrator

Like I said above, single bullet Motorcraft choke cap 7ish volts (the black/white stator wire provides about 1/2 the rectified 14ish V alternator output)

Two spade Holley choke cap uses 12V. Because not all brands of vehicle are set up the same way as Ford did it.

As Bill pointed out, the Motorcraft cap would fit right on the aftermarket Holley carb. (This is how my truck is set up)

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

ArdWrknTrk

Re: 4V Choke electrical voltage

Administrator

In reply to this post by BigBrother-84

The documentation that comes with your new Holley carb will tell you the choke cap requires 12V and ground.

You may be confused because the OEM choke cap has a little plastic nub to limit the amount of adjustment (per federal regulations) but it's simple enough to file this back, and then it fits fine in the Holley retaining collar.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: 4V Choke electrical voltage

Administrator

In reply to this post by BigBrother-84

Jeff - I think the old carb's choke is a 7V unit. And I think if you take the three screws off it and the one on the Holley they may interchange. But make sure they are both wound the same direction so they open the choke up when getting hot.

As for a relay, it is a fairly simple solution. Below is the wiring on the power distribution box on Big Blue, but it shows how the choke relay is wired. You can put the relay on the fender near the starter relay and pick up power from the starter relay by running a fuse between the relays.

I bought these relays from Amazon and like them 'cause they are nicely sealed. And I bought these fuses, which work out well.

If you are interested I could draw up exactly how to wire it, and it isn't hard to wire.

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

ArdWrknTrk

Re: 4V Choke electrical voltage

Administrator

The Motorcraft choke is definitely 7V and it operates in the same direction as Holley.
(note what I said above about the adjustment limiting nub)

IIRC there were some 351 engines that did come with a choke relay....
Here it is from the '86 EVTM

Edit: G801 is shown as behind the LH headlamp

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: 4V Choke electrical voltage

Administrator

Good example, Jim. But I think you are suggesting that it would be easier to swap the choke heater, and I agree.

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: 4V Choke electrical voltage

Administrator

In my mind there's a lot to be said for keeping the original set-up, especially as it's been proven to work well (35 years in my case)

I realize that the winters here may not be as cold as Ontario but my choke has worked okay at -20F.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

85lebaront2

Re: 4V Choke electrical voltage

Administrator

In reply to this post by BigBrother-84

You don't need the metal shell, the retaining ring from the new Holley will work fine. Just start with the reference notch set the same.

Bill AKA "LOBO" Profile

"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413

BigBrother-84

Re: 4V Choke electrical voltage

This post was updated on .

85lebaront2 wrote

You don't need the metal shell, the retaining ring from the new Holley will work fine. Just start with the reference notch set the same.

Ok Bill, I'm willing to give a try tomorrow. But as a regional doctor operating a delicate surgery not in his qualifications, I'll need to be remotely supervised by a specialized surgeon.

My first "mechanical exploration" was at age of 4. Decided to understand how the hell a Big Ben table clock was working.
Disassembled and opened it when suddenly a spiral spring jumped out of its heart. Was never able to reassemble it, had to apologize to my Mom (with some tears) about this disaster.

I know there is a spiral spring in this cap, I'll have to "hook" it correctly in its new location. Not sure how to do it... Will it jump in my face (again!)?

Will I have to tension it in any ways when reinstalling the cap? If so, how much turn, or turn fractions?

I'll proceed methodically. Will first take out the old cap, examine it, send some picts and wait for instructions.

Jeff / 1984 F350 Crew Cab 4x4/5.8L w351 4V/ T18/ D50 4.10 front/ 8' bed.
Restored 2019-2022.
Nicknamed «Big Brother 1984», due to its soooo-looong shape & nod to George Orwell's 1984 famous novel.

Gary Lewis

Re: 4V Choke electrical voltage

Administrator

I'm not Bill, but I had the same experience with a clock and knew what was coming when you started down that path. But I can assure you that the spring in the heater isn't going to jump out at you. It is a bi-metal spring, meaning it has two different metals in it, one on one side of the spring and one on the other. And since those metals have different expansion rates that means that the spring will expand or contract due to temperature. But at a given temp the spring is stable.

The best tip I can give you is to ensure that the "hook" at the end of the spring captures the pin of the choke mechanism. I put the heater on the carb with the open side of the hook past the pin and rotate the heater towards the pin to see that the mechanism moves before I secure the heater in place.

Gary, AKA "Gary fellow": Profile

BigBrother-84

Re: 4V Choke electrical voltage

This post was updated on .

Okay, I have the old in hands.

I assume that some other dummies like me would do it for the first time too, so there is some picture for them (not for my Pro Teachers).

1- This is how it looks when disassembled:

2- Let's say we want to install it back. Help needed:

A) When put it back, I assume having to insert the choke pin in the spring end loop.

B) Now, does it have to be done with open or closed flap?

C) Now it is back at its place, have to turn it clockwise or counterclockwise, and how much tension the spring before tightening the 3-screws ring?

D) EDIT: Oh, and I assume I'll have to keep the old metal 3-screws ring on the new carb, otherwise the old 7V choke cap will not be grounded, am I right?

After this will be done, it will be time to talk about fine tuning.

Jeff / 1984 F350 Crew Cab 4x4/5.8L w351 4V/ T18/ D50 4.10 front/ 8' bed.
Restored 2019-2022.
Nicknamed «Big Brother 1984», due to its soooo-looong shape & nod to George Orwell's 1984 famous novel.

85lebaront2

Re: 4V Choke electrical voltage

Administrator

On the Motorcraft cover you will find a notch. For starting initially set that on the large rib on the choke housing and tighten the clamp ring. Fine tuning is fairly easy, if it seems to come off too fast, turn it toward "rich" (counterclockwise), if it is too slow coming off then go "lean" (clockwise). Do it one, maybe two notches at a time.

As far as the retainer, as long as the ring contacts one of the two metal areas on the choke cover, it will be grounded properly.

Bill AKA "LOBO" Profile

ArdWrknTrk

Re: 4V Choke electrical voltage

Administrator

In reply to this post by BigBrother-84

A) Yes

B)You now need to set the choke flap opening: either what the book suggests or what your decades of tuning experience tells you.

C) I personally like to start between 2mm/0.080" open to just touching.
The vacuum pull-off will crack the plate open once the engine starts.
If you find driveability suffers and it comes off too soon you can begin to add tension one line at a time.

D) Use the new Holley retaining ring. its not all crudded up and probably a little springier.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

BigBrother-84

Re: 4V Choke electrical voltage

Gentlemen, many thanks all of you, JOB IS DONE!

For posterity

and for other newbie dummies like me, here is a summary of what I've done:

1- Fully cleaned the old 7V cap and its ring. For comparison, there is also the new 12V one and its ring:

2- This is when I took off the new 12V cap and installed the old 7V one.
For the newbies:
- Simply insert the spring loop on the choke pin while the choke flap is opened.
- Than turn about 90º conterclockwise, the choke flap will close. I stopped turning when the cap notch was centred in the adjustment scale.

3- I decided to keep the old retaining ring. I trust it better for grounding purpose. If you do so, don't make the same mistake I did... Take off the ground wire before installing the old metal ring, or you'll not be able to do so.

4- THAN, install the old metal ring.

5- I had to make a new insulation for the old wire, the original rubber was completely gone. Did it with multiple heat shrink tubing:

6- Et Voilà!

The truck started very well, the closed flap began to open after couple of minutes (max 20ºF here today), Big Bro seamed happy.

Again, many thanks to all pros for their patience explaining me the way it works!

I have some other questions about the carb choke flap itself, I'll start a new thread about it.

Jeff / 1984 F350 Crew Cab 4x4/5.8L w351 4V/ T18/ D50 4.10 front/ 8' bed.
Restored 2019-2022.
Nicknamed «Big Brother 1984», due to its soooo-looong shape & nod to George Orwell's 1984 famous novel.

Gary Lewis

Re: 4V Choke electrical voltage

Administrator

Excellent! Well done, Jeff!

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: 4V Choke electrical voltage

Administrator

In reply to this post by BigBrother-84

Congratulations Jeff!

I'm glad to hear the 7V choke coil is working for you too.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

grumpin

Re: 4V Choke electrical voltage

In reply to this post by BigBrother-84

Dane
1986 F250HD SC XLT Lariat 4x4 460 C6-Sold
1992 Bronco XLT 4x4 351W E4OD
1998 GMC Sierra SLE K1500 350 4L60E
Arizona

BigBrother-84

Re: 4V Choke electrical voltage

This post was updated on .

In reply to this post by ArdWrknTrk

ArdWrknTrk wrote

My truck has a mechanical fuel pump so it takes a lot of cranking if I let it sit too long.
Sometimes (if I know it's been a week) I resort to using a syringe to fill the bowls through the primary vent tube sticking up in the choke horn.
This saves wear and tear on my starter and battery.
«pumping» an empty bowl may give you something to do while the carburetor fills but I doubt it really accomplishes anything.

Jim (and others), I posted a movie on YouTube:
https://youtu.be/yEoUzQ9IO5s

Was cold (really) this morning (-6ºF / -21ºC), so I decided to make a "hard" test. No block heater, no battery heater. Just the battery maintainer was plugged.

Usually during winter, I plug the block heater overnight before using Big Bro.
And when very cold, I add the battery heating blanket.
But I wanted this morning test to be very difficult.

Remember that Big Bro starts one or two times a month.

As you'll see in the movie:
- Big Bro needs its carb bowl to fill.
- The colder is the weather, the more I need to pump before getting a first spark. Much easier in summer.
- If I do not pump the pedal (letting the mechanical pump to do its job), it gets much longer to get the fist spark.
- I stop pumping at the second I feel the engine wants to start.

I am wondering how I could fill the carb bowls without pumping. Jim, you mentioned the use of a syringe. Where do you inject the fuel? Possible to have a pict about this method?

Thanks!

Jeff / 1984 F350 Crew Cab 4x4/5.8L w351 4V/ T18/ D50 4.10 front/ 8' bed.
Restored 2019-2022.
Nicknamed «Big Brother 1984», due to its soooo-looong shape & nod to George Orwell's 1984 famous novel.

grumpin

Re: 4V Choke electrical voltage

I think, considering that it’s a mechanical fuel pump, carburetor, a little cold out (

) and hasn’t started for a week, that it is great!

Dane
1986 F250HD SC XLT Lariat 4x4 460 C6-Sold
1992 Bronco XLT 4x4 351W E4OD
1998 GMC Sierra SLE K1500 350 4L60E
Arizona

mat in tn

Re: 4V Choke electrical voltage

In reply to this post by BigBrother-84

not sure that you I am understanding the pump. accelerator pump or fuel pump? the fuel pump has no connection to the gas pedal.

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