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Cold weather start is rough

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BigBrother-84

Cold weather start is rough

This post was updated on .

Hi gentlemen!

Cold weather is coming back, we’re waking up under freezing point every morning since almost two weeks now. 3" of snow yesterday night.

Since my GMC Terrain is at dealer’s garage for a week now (they are waiting for a part), I use Big Brother as my daily drive vehicle.

Cold start:
• After pressing the pedal to the floor and slowly leaving it up, get off my feet of it and turn the ignition key, he starts instantly.
• He runs smoothly for 4-5 seconds, then the engine begins to run roughly. At lot of exhaust smoke.
• Runs this way for the time it takes to warm enough so the choke flap begins to open.
• Then, almost instantly, no more “rough running”, runs smooth and RPM are going up as the choke opens, this until 100% opened.
• After couple of seconds lettings this high RPM going on, I touch the pedal and the engine goes down at its normal RPM (around 750-800).

Question: Why this rough behavior chapter until the choke begins to open?

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: Cold weather start is rough

Administrator

You have the original carb, the Holley 4180C, right. If so it sounds like you have the choke plate is closing too far. I say that because you said that the smoke starts after 4 to 5 seconds, which I would think is before the choke heater could possibly be expected to bring the choke off.

But the process to adjust the choke closing, aka "choke plate pulldown", isn't straightforward, as shown in the snippet below from Ford's service manual on that carb. That being the case I'd back off one notch on the choke setting.

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

BigBrother-84

Re: Cold weather start is rough

Gary Lewis wrote

You have the original carb, the Holley 4180C, right. If so it sounds like you have the choke plate is closing too far.

Gary, I replaced Big Bro’s carb not so long ago.
This new Holley carb has a “partial choke flap” design, as I already posted in this thread.

Could this has to see with my «rough running» cold start?

Gary Lewis wrote

But the process to adjust the choke closing, aka "choke plate pulldown", isn't straightforward, as shown in the snippet below from Ford's service manual on that carb. That being the case I'd back off one notch on the choke setting.

Can I apply these instructions to my “partial choke flap” carb?

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: Cold weather start is rough

Administrator

Oops, I forgot that.

I doubt you can use those instructions on the different carb. Bill's the guy to ask how to adjust that part on that carb. But I'd still back off one notch on the choke cap.

Gary, AKA "Gary fellow": Profile

BigBrother-84

Re: Cold weather start is rough

This post was updated on .

Gary Lewis wrote

But I'd still back off one notch on the choke cap.

Well, I said to myself «Why not give a try, it won't kill anybody».

1- Cold position, before any move:

2- After depressing the pedal ("partial" choke flap 100% closed):

3- After ignition, when it began to "rough run" after the initial 4-5 seconds, I forced the opening a little bit with a screwdriver. Looks that it helps, the engine runs smoother:

4- I stopped immediately the engine (so it stays cold), and I decided to modify the position of the choke heater, turning it a little bit clockwise. This places the cold flap position slightly opened:

New cold ignition, the engine starts immediately and after the initial 4-5 seconds, the engine continues to run smoothly. "Rough run" seems to be gone.
I'll test this setting couple of cold mornings before declaring the issue solved.

Gary, you had a good intuition!

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: Cold weather start is rough

Administrator

Wonderful!

Gary, AKA "Gary fellow": Profile

FordFETruck

Re: Cold weather start is rough

Those newer Holley's without the choke pull off and the slotted choke in my experience are horrible and it was just a way to save cost on manufacturing at the expense of a poorly running engine during warmup in most cases. I have a quick fuel SS780VS on a Ford 445 FE stroker that is the same way, and it was so terrible trying to get it to run right on choke I converted it to manual choke. I'll never buy another automatic choke Holley that's like that. The Summit racing 4010 series carburetors still come with choke pull off, I put the 7 volt Motorcraft choke thermostat on those wired to the stator wire on the alternator and they start and run nearly as well as EFI.

1986 F250 351W, C6, 10.25 Semi float 3.55 gear, 250K Miles

BigBrother-84

Re: Cold weather start is rough

I already swapped the original 7V thermostat to this new carb.

But, if I still have cold start issue with this carb, I begin to think about sending my original carb (which I still have) to a specialist, for a complete rebuild/restoration…
🧐

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: Cold weather start is rough

Administrator

The 4180 isn't difficult to rebuild but you absolutely need to get the correct 3-1346 kit.

A generic 4160 kit won't do.

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: Cold weather start is rough

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: Cold weather start is rough

Administrator

In reply to this post by BigBrother-84

I can't restore the plating, but I used to own a shop that was a Holley authorized warranty location, Preston Carburetion, located in Newport News VA. I am now on Virginia's Eastern Shore and have plenty of time if you want to send it to me.

Darth had a 4180C until he was converted to MAF/SEFI in 2012 (first was the SD/BF system in late 2011).

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: Cold weather start is rough

Bill, you’re the man!

I’m not looking for sparkling and shiny carb, if I could just have Big Bro’s working as new, would be my dream!

I’ll send you an email for your address and see how I can ship it.
No rush, as the truck runs well… after its cold start.

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.

BigBrother-84

Re: Cold weather start is rough

In reply to this post by 85lebaront2

Email sent.

Bill, I know that the forum “mail” function isn’t always reliable.

Please post me if you don’t receive it, maybe Gary could help me about this.

—Jeff

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: Cold weather start is rough

Administrator

Email sent to the two of you.

Gary, AKA "Gary fellow": Profile

BigBrother-84

Re: Cold weather start is rough

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.