The automatic choke is a system with hundreds of variations and dozens of ways to malfunction. Here's a quick rundown of how they work, and why you're probably better off without one at all.
I cried out to God one time with regards to a poorly performing automatic choke, and he told me that he had, indeed, intended for all chokes to have manual cables...
Yup, then my mom would load up the neighborhood kids, and we go in town racing LOL Memories I never wanna forget. She would be in jail doing that today. LMAO
@@diymisfit_Mechanic_UDX404 My mom had a AMC Concord. Not doing much racing with that. Now the 72 Olds Cutlass with the 350 rocket she had before this, was a different story lol
That's why the air cleaner lid was held on by a wing nut, so you could remove it by hand to get access to insert the screwdriver blade so it held the choke plate open a bit. I'm surprised that they didn't add a strap to make the wing nut "Captive" so that it wouldn't get lost in all the excitement of the cold-morning start-up routine.
I love old school carburetor talk. I grew up on cars with these. I intuitively learned how to feather them. Listening to tell rich from lean, long before I learned how they worked. If you didn’t? You couldn’t drive anywhere in the winter. The automatic chokes with the heat crossover worked pretty well...until the coil spring in the exhaust pipe broke. Or the weight rusted and fell off. For ultimate reliability, like the ‘53 Ford, 3 on the tree, I drove into the early 1980s, the manual choke was the “Bee’s Knees”. It did tend to get carburetor icing on a cool/cold and humid morning and wouldn’t idle worth crap. I devised a work around. It involved the bottom of a 5 gallon bucket cut to fit over the oil bath air cleaner, a 3” PVC Tee and pipe, and a manually operated butterfly valve made from the metal lid of a jar of peanut butter. With some aircraft heat ducting connected to a makeshift sheet metal contraption over some of the cast iron exhaust manifold. It worked like a charm, barely. I’m serious as a heart attack. I was commuting to school in LA and it was very bad to have your engine die on an uphill stoplight during morning traffic. That was about a block from my apartment. I worked as a gas pumper at the local airport in the summer. and scrounged the design idea and parts from my bosses junk pile. The engine eventually broke a rod cruising home North on I-5 in Northern California to Medford OR. My Dad and Mom came with his Minnie Winnie motorhome and strap towed me to the far side of the Siskiyou pass brake check area. He said I should just coast down the ~15 miles to Ashland and then he would tow me home. It worked great...except it was raining fairly hard and the ‘53 Ford’s wipers were vacuum powered. No engine? No vacuum. No heater. So I had to keep the window down with my hand and arm stuck out in the freezing cold rain to manually operate the wiper. All while watching my Mother staring at me out of the back of the motorhome with a concerned look. It’s a steep winding freeway mountain road with a couple of truck runoffs. Fortunately the rainwater kept my “high tech” 4 wheel drum brakes from fading. My Dad put a rebuilt engine in it and used in Portland OR where he was based as an airline pilot. Where it is cool/cold and humid. He called and said it kept dying on him when cold. I told him to put my Rube Goldberg contraption on the engine. He always looked at it as a dubious thing. He called me back and said “GD it works”. I learned everything in know about cars and mechanics from my Dad. I miss him.
@@Ivusmchine Thanks, Brother. There's more strange, almost unbelievable, twists to the story. That are interesting. I still miss my Dad. Thanks for the nice considerate comment.
Remember back in the day late 60s-70s.. you could smell that one car in the neighborhood that ran so rich it would come through the screen door and burn your eyes and nose.
@@PistonAvatarGuy today's carbs are well designed and work well. Carbureted hotrods work and are not necessarily sloppy. Spending ridiculous money on a fuel system, other EFI parts, and spend many hours tuning and data logging isn't for everyone either.
When I rebuilt my Satellite I put in a manual choke on my Edlebrock on purpose. The weather here in Iowa is unpredictable at best.I also inadvertently dropped it back open halfway after starting without realizing why. It just ran better. Now I know.
This is fantastic information. I have been driving my first carburated vehicles for almost a year now and you described everything that has been happening PERFECTLY. My truck came with an aftermarket Edelbrock carb... and yep! The only issue with it I've had is exactly what you mentioned toward the end! If I stop somewhere after I just started it... there is a good chance I have to fight it to start up when I get back in. But every morning it fires right up like a champ. This has been really really frustrating but now I know why! Thanks so much and keep these videos going, they are so helpful to us younger guys that grew up with nothing but EFI.
I bought an 84' AMC Eagle about 6 months ago and have barely been able to drive it because of that exact reason you explain with the choke pull off.I was born in 91',I know EFI and newer tech so It's back to the basics for me
Can totally relate to that one...my hemi...cold...pumped the throttle 8x...she lit right up....hot....don't touch it 'cause a flooded hemi is a bitch to start....
Your videos make me really miss an old, beat up '55 Studebaker Commander I had in high school. Big cast iron V8, 3 on the Tree, two barrel carb. Coolest kid at my high school for 08 and 09. Sold it to a restorer when I needed money for college. Really wish I kept it. That car taught me so much about how to work on cars. Including carb tuning and that dang auto choke.
I was always told that auto-chokes were no good, but I never understood why - thanks for the explanation! We have a Holley on the 318, not sure how that is set but at least I feel confidant to go take a look and have a semi-knowledgeable conversation with hubby about it lol, and my own build has a Weber that I'm converting to manual choke. I know a lot of adverts push towards EFI, but at MY level of understanding, I'm going back to basics and taking it from there, and I am getting so much good information here, I love it! :)
Yeah, if you live where the weather stays about the same all year round, they work well, but around here we go from 110+ in the summer to 0 and below during the winter. I found that I had to readjust edelbrock's in particular every spring and every fall, but if I adjusted them on a cold winter day to where the spring just barely holds the choke closed, they usually did ok during the summer, I'd just have to pump them a couple of times.
@@livewire2759 that's what I do with edelbrock and I dont have any issues, just a couple of pumps b4 I start and she takes off. Of course I live in south Carolina and our weather isnt that extreme.
I hope you and Uncle Kathy are completely safe from those tornadoes I just read about. I look forward to, and learn from each new video. Thank you and God Bless.
Good stuff!!! Definitely had my share. That was way back when there was still a service known as a tune-up.Wow that's old! Almost going back as far as Dave at the Old Steam Powered Machine Shop. Well, maybe not that far. Kids, pay attention to Uncle Tony. You're never too young to learn old stuff.
Just thinkin. Uncle Tony, if you want, you can take the tagline of my last comment and use it on some kind of decent swag. Maybe get a little something going to help Lambchop with the expenses that crop up with his type of treatment. I made it up as I was writing so it's ok to use. The '...never too young to learn old stuff' fund or something. Yours if you want it. To Uncle Tony from Uncle Mike. L8r.
been watching your videos for a while now, i must say this video in particular was really helpful in understanding why my carbed car is a pig to start cold, your videos in general are great for me to just have a better understanding of the older systems, even though im from the uk the systems are almost the same all be it smaller carbs haha
Growing up, my mom's 68 Newport with a 383 - 2bbl would have starting issues on really cold mornings. We always kept a screwdriver in the car, which I would grab and stick down the carb just to keep that butterfly from closing up completely while mom cranked it and got it running. Now I start my truck with my cell phone... ah the good old days!!
My first car was an old vw. I had a great book on vw's in which the author swore auto chokes were a conspiracy by manufacturers to shorten engine life. His first suggested carb adjustment was to disable an auto chokes and just let the car warm up for a few minutes.
i have heard the same! i had a 1972 mustang 351c 2bbl it had the choke wired open and it started up like efi! that engine has all the original stuff but the common tune up stuff! so from that point i had never had a choke. i remove them! yes you have to let them warm up but it is not a problem. using a clutch fan helps. i have let people start my other rigs and thy are used to the 1-2 second dely efi has and ended up grinding the starter as i lit off so fast! it all so wold out do efi in fuel economy to!
love your channel. old engine builder from down under.slowly but surely resurrecting my 66 charger .383 orig car,going back together with 440 cranked 400.liked your video about back dressing your slant6 intake valves,have done something similar back home with a die grinder with a small emery flap wheel ,puts a nice swirl pattern on the under side of the valve.when you did your demo,ya nicked close to the stem with your file,if left like that,might drop a valve.that just stuck in my head.like i said before,love ya channel,always look forward to your vids!
You brought back a lot of memories. I used to do a lot of carb work-rebuilds. Some carbs had to pull offs to adjust. I can remember doing the initial startup after a rebuild adjusting the choke pull off and high speed idle and kick down solenoid fun days. I have to vehicles and one has a manual choke the other has the holly carb original equipment ford factory 4 barrel but I plan on converting it to manual operation in the future when I go through the motor.
Do as God intended 😂. After watching your channel for a while I've begun to marvel at the complexity of the systems that developed, all so we wouldn't have to manually choke it anymore. How ironic that the failure of this complexity lead to the bone yard. And the addition of complexity has only compounded in recent years. Thanks for the great info Uncle Tony!
I just spent about $700.00 on my sbc with a 600cfm. The motor would crank & run beautifully, but when I drove it, the low end power just disappeared one day and the motor backfired. I was incredulous. That happened 2 months ago. I've gone through 2 mechanics & 500 RU-vid videos. After watching this video I went outside & checked my carburetor... it was particularly choked...smh The lever inside my truck wasn't adjusted or able to unchoke the carb. Thank your Sir... you saved my 1972 Chevy truck.
I always enjoy coming to get a tidbit of knowledge to pass on to my children from you… Before reminding you that it is within your power to stop smoking. I love what you are doing for the automotive community and hope you were able to do it longer by conquering a difficult challenge for you and me and everyone. Do it when you’re ready. I hope it is soon.
I remember my 2nd vehicle was a carborated 2.0L ford with an auto choke, it would run differently everytime you started it. Go into town it would run alright, get back in it would run so so, sometimes it ran great and others it would spit and chough, we switched it to manual choke cable and things got significantly more consistent. Good vid, its truer than most would believe.
The first carburetor I ever rebuilt was on an 86 Cutlass Supreme. The mechanic I was working with slid it across the work bench and said you do it. You won’t ever understand them if you don’t repair them. Another overlooked part it a worn throttle shaft. Definitely a spot for a vacuum leak causing an erratic idle
I've just pulled the choke off completely and feathered it, kind of sucked during winter but other than that it stayed at a idle no problem. Very educational video thanks Tony.
Perfect video - perfect lead picture! Chokes are THE NUMBER ONE pain in the ass with carbs. I've been lucky, a good many of my automatic choked cars worked like they should or close enough they weren't a problem..... But some of those bastards got replaced with a mechanical choke, or ripped out, choke plates and all. I never had a carb related "no start" even at -20° with no choke, I can't say my EFI cars did as well. Below a given temperature, the ECM says "fuck it" and goes dead rich, and 8 injectors do a much better job of flooding an engine than ANY carb.
Last time I drove a carbureted vehicle, it was a 1978 Chevy C1500 long bed pickup with a stovebolt 6 and three-on-the-tree manual. The guy had taken great mechanical care of that old truck, I pumped the gas twice as instructed, and the engine barely turned maybe 3 revolutions and started right up from dead cold (65F ish degree day) and was amazing to drive. That was a great example of the auto choke working perfect.... My neighbor just got a 1980s Ford F150 recently, and I think he is having choke issues because the truck acts dumb till it is warmed up. This all said, I prefer manual chokes. You know for sure if they are on or off, and if something goes wrong, MUCH easier to check for the reason.
Thanks for knowing as much as you do. I figured out how to make an Edelbrock electric choke work functionally. I ran with it disconnected for a while which has its own problems. I figured after your explanation, just put a switch for the choke in the vehicle. If you don't need it, turn it off. Interesting that it doesn't have its own pull off but thanks for the insight. The choke plagued me when I had it running and I don't like incomplete systems in my truck so this is now on my list of things to make driving this thing a bit better.
Thanks Uncle Tony! Takes me back to my early days as a mechanic unplugging hot air crossovers on our fleet of early Dodge vans with carbed 318s in them. Lost science now!
Thank you for this. I used to drive a 1969 Ford F250 4x4, with a manual choke. I loved it. I could make it start in any temperature. The coldest, -50 C ( -58 F) and believe it or not, it started right up, without being plugged in. that 360 was a beast. I had to hold the clutch for 5 minutes or it would immediately stall. My Wildcat, automatic choke. It seems to work great, goes to high idle, about 1200 RPM until the COLD light goes out.
I just rebuilt my Holley 4160 today, this was perfect timing. The choke isnt functional at the moment but has the mechanicals for it, I have it locked open but will probably hook the manual pull cable up to it. UTG videos are like crack to a wannabe hotrodder!!!
That helps a lot! Partially explains some of the start up issues I see with my ‘77 M880. Pretty cool how all these mechanical and vacuum systems work vs computer FI.
Hey Uncle Tony, I’m with you I just have it disconnected. Although it can get can cold here in Australia it’s never that bad that you actually need the choke. Cheers😊
Problem solved! Thank you so much! Nobody could seem to answer my question about the choke pull off. My old school chevy has been chugging and loading up when it's cold and couldn't figure out why for years! Thought it was the bimetal spring but my old quadrajet has that pull off. Once I fix that she should run a lot better. And yes, I have a terrible soot problem. I hope once that's fixed that soot will blow out. I might partially plug one side of my dual exhaust to try to clear the intake crossover.
Hey Tony , I’m 62 years old and only last fall bought my very first EFI 1990 Scottsdale 1500 with 129.000 American miles on it . Have only ever run q-jets since the seventies. My dd work truck with Ht383 crate has two block heaters and two hot air snorkels ( junkyard parts but looks factory with all vacuum doodads working ) drawing hot air off two ram horn manifolds . Here in northern Canada i often start it at 20 minus Celsius. Two pumps and it idles at 600 rpm no stumbles and NO fast idle either. Thanks to the block heaters, with out them I’d be screwed. I love the sound of these cold starts . Something sexy about them , just like old ww2 airplane motors, minus the blue smoke. Putters some and the after 20 seconds levels of to a nice even idle. An honest sound. In the summer I run an open air filter and love the sound of secondaries in sync with a raspy x pipe. Lotsa pretty girls turn their heads to see where that sweet music comes from only to see my dd 1ton . Love your show .
I learned how to adjust the choke and the pulloff on my Thermo Quads and the lil 2 bbl Carter most of my cars had at first. IF you get it right they'll start right up after one quick pump to set the choke and get a shot of gas in to prime it. My Dart would start on one pump with the 9800 series electric choke TQ, same with sisters Scamp. If it took longer than 3 cranks something was wrong or it was flooded. It is a black art and I grew to understand all the interrelated adjustments on the TQ and the bbd carbs. Most folks didn't have a clue so it either worked or they fought their cars in cold weather. There are measurements and adjustments in the true manuals for them that will get it close enough to work as long as the carb is already jetted close for the engine and you can fine tune from there. I bought a 78 318 200 van and I had to set the choke and pull off for it once I got it home and I hadn't had to touch one in years but knowing what a 318 typically likes I got it right fairly quickly. Once they are right you shouldn't have to touch them again till something breaks or wears out. I even have a TQ strip kit and for a AVS and The AFB though if you kept all the parts the same you could use parts from either kit. Mopars usually used the 3 step metering rods and everyone else used 2 step and the matching jets from the factory. My Dart tested better emissions wise than many new cars in the early 80s after I fine tuned the 383 AVS I originally used before I swapped to the 9800 TQ I bought at a swap meet for 2 bucks and rebuilt. I ran that one for probably 15 years before I finally had to rebuild it again.
With all due respect, I will say, in my experience, that the accelerator pumps are the biggest issues...especially with the Edlebrock 4 bbl if NOT used often! May be different issues in different parts of our Great Country. I am in So Calif
SoCal fuel is pretty bad on rubber parts. Try to get a pump that uses Viton as the material. Much more ethanol and solvent resistant than regular rubber or leather. Keep an eye on your lift pump too if you have a mechanical style lift pump.
Lol I’m glad you mentioned that! Every single edlebrock carb I put on my V8’s I used a manual choke to deal with the bad automatic system. Finally got tired of it and went with a sniper efi.
Good grief, what a long list of things to go wrong! Have manual chokes on all of my Webers, and I have never even used it. Just pump the pedal, and she starts. Thanks UT for another illuminating video.
Thank you, UTG. I had decided to use my foot as the "choke adjuster" a long time ago, getting rid of the electric unit, while it warms up. Manual add "on the list".
Uncle Tony I am surprised those "Roadkill" boys over at Motortrend haven't pick you up yet for a show. Id watch it. Great videos, always love learning about this stuff. Keep on my man you rule!
At one time, I made a living just fixing quadrajet chokes and choke pull-offs in the winter. For some reason, people had a hard time understanding, “one pump, turn the key to start, warm up, tap the throttle to idle” . They had the need to pump the pedal five times and flood the motor, it was crazy
ANY other carb than an effing Q-jet, and you could get away with five pumps! LOL What I found most of the time is they couldn't just pump the carb and leave the foot off, they would pump, and pump, WHILE they were cranking.
I got my choke tuned to perfection( manual) .... it’s held open with a spring lol. It’s a fair weather cruiser stored in a heated garage so I don’t really need it. Great information tho tony looking forward to more . Thanks.
Most quadrajets had two choke pull-offs, a primary and a secondary. The secondary choke pull off, the one that the back of the carburetor, has a calibrated vacuum leak in it new and will always bleed off.
Here in Ontario Canada all the cars my dad owned got manual choke. He never liked relying on the factory garbage. He also used to have marks on distributor cap summer and winter. Made super easy to get the tune in range with the changing seasons.
I spent 47 years in the auto repair business from my family's service station to a dealership. I have serviced uncountable numbers of carburetors and chokes and the one thing that I can say from my experience is that manual chokes caused more problems than they cured. If someone had a cold performance problem they knew they had a problem and brought the car in for service. The vast majority of the time the repair was quick and inexpensive.
I did not realize there was a pull off inside there, a summit carb I recently played with said that hole wasn't drilled out of course I assumed it was for pulling manifold heat thru the spring. Sometimes I'll take the PVC hose and wrap it around the spring cover, just to assist in warming it up. Thanks uncle Tony, as always
I've been toying with the choke on a farm-fresh '85 K10. That was about the last year for a fully mechanical carb and bare bones ignition, but by then all the adjustment screws were blocked off or replaced by rivets. Though the worst part is finding parts that work; the bi-metallic elements don't allow rotational adjustment without assistance from a pedestal grinder, and the vacuum pull-offs are being sold for 75 flippin' dollar-roni's. But it's ok, it's now one of the most reliable vehicles in the fleet.
In the mid/early '80's, I went off to GM 'school' to learn about the new, 'computer' cars, (remember the Citation?). One of the things GM taught us was to take the Q-jet off, turn it over and physically break open the casting, so we could get to the hidden idle air-fuel adjustment screw. As we sat in horror, watching the teacher pound on this $1000 carb, ($3-4,000 in today's dollars), trying break out this casting, he warned us to be careful doing this, as it was easy to fuck up the carb. At the time, some corporation was using 'a better idea' as their catch phrase in their TV commercials, and it had become a popular 'meme'. Someone in the class says, 'Now, that's what you call a better idea, and everyone laughed.' I then proceeded to gain the instant dislike of the instructor, when I asked, "Speaking of better ideas, is there any valid reason GM came up with the side mount battery, other than to sell more batteries and cables?" He couldn't answer, and never really liked me, from that day on...
Well I learned something from this.... I had no idea what that crossover was for ! I knew it was there just didn't know why ! Very cool too find out ! Thank you 😎
The only carbureted vehicle I ever owned was my first. It was a 1986 Toyota 2wd regular cab short bed with the 22R 4 cylinder with a 4 speed. I bought it in 1988 with 77k miles and sold it in 1993 with 194k miles. I never had a lick of trouble with the carburetor. From -15°f to 100+°f, it always started on the first try, even during the summer I couldn't afford to replace the starter, it still started on the first pop of the clutch going forward or backwards, even pushing it across a flat parking lot by myself, except when I forgot to turn the key to ON. I miss that truck 🥲 and would love to have another just like it !
Good video on this. Factory chokes are a pain to get right and even the aftermarket ones are finicky. Usually only have one or two tries to get it right then have to let it cool off and try again.
I once had a ‘62 F-85 with a 215 v8. It had a Rochester 4-bbl that was not running right. I took off the carb, installed a kit and adjusted all the settings as per the instructions. It ran flawlessly after that. The carb had an interesting feature. With a partially warm start, there was a small vacuum servo that would raise the idle a few hundred rpm. This would happen without any throttle input, and only last for about 5 seconds, then idle down to the stop screw setting. Clever idea! I loved the car... all except the tranny, a 3-speed hydromatic... not a TH! The 1-2 shift was miles apart in ratio. It would have been more fun with a 4-speed manual.
I'm happy to say I've never had a vehicle with an automatic choke. I went straight from manual choke as a youngster to EFI in the mid '90s, skipping everything in between. Happy days. :-)
My 78' Holden Kingswood (here in Australia) has a Stromberg BX carburretor with a manual choke straight from the factory and I love it. The automatic chokes don't seem worth the hassle! Also the BX is a very simple carburettor, so I like it too- even if it's only a single barrel. Gets the job done for my straight 6 engine.
I concur UT! I have an edelbrock 500 AVS on my mild 318 with a manual choke. I used to use the choke but once it was tuned properly I found it didn’t need the choke at all! Also my edelbrock suffered from the dreaded edelbog when hitting the secondary’s. I read somewhere that the choke flap can hinder this so one day while tinkering I took the choke flap off completely and to my surprise it really did get rid of most of the bog that was there! Still bogs a bit but I believe that’s largely due to my diff ratio of 2.92. I was impressed as it was an easy fix.
You nailed it. The automatic choke is by far the biggest downfall of any carb and not needed if you know how to pump a gas peddle and keep it at a high idle for a few minutes. I've bought dozens of GM products with quadra jets and I disco the pull off and wire the choke open before I even leave the people's driveway or lot. Nothing worse than stomping on the loud peddle to find out the secondaries won't open because of the choke....
