When I worked at a Dodge dealership in the 70's and early 80's, plugged crossovers was a common problem. On Chrysler products, the crossover has to be open and the exhaust damper has to function correctly or the choke will never fully open. We cleaned many intake manifolds and rebuilt many exhaust dampers. It seemed to be worse on the newer engines with EGR. A rule of thumb was that if you touch the intake around the choke with a fully warmed engine, it should leave a little skin.
Years ago, when I started off in an engine machine shop, I had to tear down the engines to be prepared for overhaul. I know exactly what Uncle Tony's referring to when It comes to those passage ways basically becoming a black diamond. I Would just toss them in the big oven and literally bake them overnight @ 750⁰. When I came in the next morning they would be still pretty warm. Then the carbon just basically turned to powder. So it's not real bad to clean them but still a pain. Thanks for sharing!
Tony gets it - it's the *stories* that go along with each and every one of these old cars that make them matter, make them interesting, make us love them. The history of each are what makes this a true hobby. - Ed on the Ridge
Most of us, in those days went to manual control. It only cost $2 and solved the problems. In 1970, I took apart a choke on a '63 Chevy 283 that had been assembled backwards at the factory(choke off when cold and choke on when warm) or sabotaged at the dealer. Ten minutes and it was working fine. Good Luck, Rick
My late father was a mechanic back in the day and I remember him telling me that most of his customers who tried manual choke conversions were not happy with them, and asked to return back to automatic. Granted his customers were not "car guys" who are more receptive with returning to the slight inconvenience of an old school hand choke.
I had a 62 Chevy 2 in 1998 with straight six (no chock at all) on cold day just pump gas twice crank right up. Hot day just turn the key. It would idle all day without skipping a beat.
If I had a dollar for every hour I've spent chiseling carbon out of Mopar manifolds, I think I could buy another old Mopar. Then I could spend more time knocking carbon out of that one.😆
UT, I'm glad to hear about keeping the cars history intact. The scribbles ARE part of the cars life story. I have a 58 year old, inaccurate tach mounted with an exhaust clamp by the original owner of my cherished 1965 GTO. I'm also leaving it as part of the cars history and nod to the original owner.
That intake may have been a throwaway 40 years ago, but not today. It is NOT that hard to clean out the hardened carbon. I’ve done it on three 318s and it isn’t that difficult. But it makes a massive improvement in driveability.
I remember back in the 90s watching my dad do the same thing with a infrared thermometer that looked like a space laser. He used to tune carbs by header temp and smell. Really glad you're putting this info out there as these seem to be the more arcane tricks most people don't know.
@@redlight3932, you Can still work on your cars..... just get out the credit card, spend about $6,000 on bidirectional scanners, oscilloscope, good meters. Then watch Eric at South Main Auto. If he can do it, then you can do it ! ! ! There... problem solved !
I blocked off the exhaust crossover on my ‘70 Charger with the aluminum Edelbrock Six Pack manifold. Worth a few HP, and then installed a manual choke.
Manual choke even easier than finding a new manifold. A small four barrel makes it run so much better even if you arent looking for more power. I had the same setup on my old 318, threw away the stock carb and replaced with a junkyard Edelbrock . It ran better at idle, started easier and had more power. I get keeping things stock but sometimes its just too stupid to do.
Agreed, manual choke all the way. And I blocked off the crossover on my manifold to keep the intake temps cooler, though I wouldn't recommend doing that unless you have a crossover pipe on your dual exhaust.
As I understand it, 4 barrels could be slightly more efficient than twos as long as you’re not flooring the gas pedal every chance you get. Having gotten my license in ‘75 I try accelerate smoothly and anticipate stops by letting up on the gas.
@@outlawbillionairez9780 My old Volvo had a blue light that came on when the engine was warmed up that said choke.It went off when you pushed the choke knob all the way to off. Engine never fail to start with a manual choke.
My '71 Fiat 124 had a factory manual cable choke. It worked perfectly. All my old motorcycles have manual chokes. Its somehow more satisfying when you have to interact more with the machine.
Having worked as a Emission/driveability tech back in the the day i ran into this problem a stuck heat riser valve in the exhaust was a major player in this i dont know how many of those i have replaced but it was a lot ! keep up the good work Tony !!
Back in the day I cleaned out dozens of 318/360 heat passages on those things. Being in Canada, at -30f i did about 6 a week. I have seen the whole carburetor frost up, inside and out, especially when it was humid and cold, with the complaint "it keeps stalling" or won't idle when it's cold and damp.
That alternator belt is loose. I solved the choke problem on my cars. I removed the damned things. I live in Phoenix, AZ, where chokes are not needed. Pump the pedal a couple of times, and the engine will start right up. I always warm up the engine before taking off. I have never believed in putting a load on a cold engine. EFI is more than 10 times more complicated than a carburetor, so there are a lot more things that can and do go wrong. The last several years I worked as a professional mechanic for a large government fleet department, I had to deal with thousands of check engine lights. Automatic chokes have always been an issue, but they are a simple and easy problem to get rid of. Either get rid of the choke altogether, or use a manual choke.
Stuck a manual choke on my '69 340. Solved. Now if I could only keep the eddy's fuel bowls from evaporating away after the car sits it would be perfection.
Back in the day we'd cut up a coffee can to create block off plate for the crossover passage in order to keep the fuel/air charge cooler. Our Holleys had manual chokes anyway.
Very true about blocking any manifold heat for an engine that will see a track. Cooler air is denser, which means more power, and in racing, you want to WIN by an inch, not lose by an inch. On a street engines, you WANT manifold heat, as a warm manifold means a stable air/fuel charge - in the winter, the gas will tend to fall to the walls of the manifold at lower speeds until you have been driving for quite awhile.
I ran into that with a 283 years ago. As it was my daily driver and already had an old wore out Rochester 4GC four barrel carb, I did the street aluminum intake and a 390 Holley w/ vacuum secondaries along with a manual choke. Problem solved, the Nova ran great and got good mileage. Those old 4GCs at that time were very hard to find, which is why I went with the Holley.
This is why I always use a Manual Choke and completely despise an "automatic" choke and I'll go so far as to say that 90% of all classics you get your hands onto will have this issue. A machine shop can knock out that cross-over and it's not that bad on price, but it's included in all the rest of the bill when we take them an engine to make ready for assembly. Good stuff as always UTG.
I once came across this fellow having trouble with his "hot" "63 Vette. He installed a rebuilt engine but could not get it to run cool around town; on the road OK but otherwise ran hot. Spending days on his problem, he changed the water pump, radiator, thermostat etc but no help. Showing me the problem, he started it up cold and within a short period, the engine was radiating so much heat, you had to back away from the engine. Looking down at the exhaust manifold, I spotted the heat riser and saw that it was installed upside down so as the engine warmed up, the exhaust gases increased into the intake manifold cross-over...
Shelve that manifold with other antiques. Check the head ports place a performer manifold and carb. Yes I know it's a daily driver. But this engine deserves it make it happy!
@@oscaracme because I'm extremely old, I worked on these cars when they were not really old. Every choke had a problem, and every exhaust butterfly was rusted in place. And this was Southern California. People ran water, not coolant, so every old car had freeze plugs rotted out. All the new emissions required stuff like air pump and hoses fell apart. No matter what Tony says, these weren't the good ole days. Glad they're gone. ☮️
318s and 360s were terrible for that. I have done countless de-carbons on those, usually having to use chisels and old screwdrivers to chip out the coal-like carbon. Don't miss those days.
Uncle Tony, in the late 80's and early 90's i cleaned alot of those intakes. Theyd give those crappy jobs to the kids in those days! Manual choke is way easier 😅 Cheers from Junk's Automotive Indiana USA
Yep . As I recall , they were called Heat Risers ? Along with what you mentioned , the cold bottom of the manifold doesnt help vaporize the fuel / air mixture beforehand . When guys ask me what I like best between carburation and electronic fuel injection ? I say that each has a purpose for a given situation ...that avoids the argument . Using the Jeeps , the cars were limited off road . If the hill was too steep , the carb worked against you due to the float . Injection has no such problem .
Uncle Tony…..I cleaned the carbon on intakes when I was just starting out in a Dodge dealership. You remove the intake and heat the passage blocked with carbon with the acetylene torch, then turn off the gas and blow the oxygen on the carbon to accelerate the burn. It does smoke and stink up the shop, but they come clean as new. Working on cars 45 years ago was more enjoyable! Another quick tip: If you can hold your finger on the choke stat longer than the count of 3, it’s too cold 😳
I have a 1970 truck 318 in my Barracuda that has a water passage under the carb, rather than exhaust gas, so i had to go manual choke. Best part, its a forged crank w/ sodium valves!
Amc with the 2100 and 2150 carbs. Have a plate bolted to the side of the choke thermo spring with those black housings. That plate holds the heatercore hose directly from the intake/thermostat housing area. So this helps heating the choke up very quickly. With this. Ive never had issues running my 360s with rusted out broken heat tube risers on the intake. It heats up very quickly within seconds. Those heat riser tubes under the carb in the intake . Also helps create vapor lock. Some guy will take the intake off and block it off to fix vapor lock
That style choke uses a 12V wire to operate in addition to heat provided by the exhaust crossover in the intake manifold. There is a heating element next to the bimetallic spring that operates the choke. The post is still there, and the wire is broken off. A switched 12V power source will open that choke.
Honestly I only have ever had electric chokes. Some of them have provisions for exhaust gases and whatnot but I have not heard a convincing argument to use one. Only potentially annoying part of an electric is if you leave the key on and the car off (rare occurrence).
I’ve never seen a carter bbd with an electric choke. Ever! Please tell us just what car had a carter bbd 2 barrel with an electric choke element in it.
@@davidleonard8369 That's not the carb that came on that manifold. The intake and possibly the engine are out of a later model car. Then someone put the older carburetor on it.
On these cars & all the ones I've owned that had carbs, I used a manual choke-always. No problems. If it came with an automatic choke, it was switched to a manual. It's not that hard to do. But your video is right on the money.
Previous owner could have also blocked them off on purpose, thinking, like Tony said, that it would make more power. Doubtful, but teenage boys will try anything for easy horsepower. I put split fire sparks plugs in my firebird when I was a kid. I believed I could feel a difference… 😂
Looks like a new camera or uncle kathy playing with the lighting in the editor. Nice! Looks good guys, nothin but gratefulness for basically free content!
With the cast iron intake manifolds, I could always fire up the torch to get the carbon out of it. It makes lots of fun sparks, too. Just do it outside, the hell away from everything else. Use appropriate shielding or do the hot ember dance. The aluminum manifolds weren't as easy.
Great video and great explanation, I just install manual chokes on my old cars. Kinda off subject kinda on subject. My son once wrote I love Dad inside our china closet , My wife discovered it and showed it to me and asked what we should do. I said nothing that’s awesome!!
The previous owner of my ‘41 Chevy tied up the broken end of the windshield wiper with a bit of string. This truck never sees the rain, so I have left the wiper and string as is. It’s part of the truck’s history.
Tony, I had a 360 in a '74 Ramcharger that would turn the carburetor into a block of ice. It actually would build up 3/8" of ice in the summer... until the intake was changed. I could warm it up and shut it off for about 15 Minutes and the block heat would thaw out the carb. then it was pretty driveable.
Explains why my mechanic 35 years ago said I had to leave it overnight for a diagnosis. I started a different comment until you explained the conflicting advice to plug the heat crossover.
When I was a teenager and the only dirt bikes were 2stroke and when they gummed up the exhaust badly with carbon and I can't remember what we used to soak out the carbon buildup in the pipe because as teens no one had any money to buy anything but gas and Tyres 😅
What about the adjustment on the choke pull off rod? It should be able to open the choke fully after a few blips of the throttle. In the summer you just need the choke to start not to stay on.
I once had a plugged intake manifold from a 2 barrel 318 hot tanked in a bath of chemicals for a few hours and came out spotless. Simpler than changing the whole intake.
I daily an 86 Nissan D21 with Z24i engine. I have hot start issues. The tbi seems to be over fueling on hot restarts. I know it could be a few things I just wanted to share some of the weird stuff. The coolant runs through the tbi and it has a wax pellet choke. It has duel sparkplugs with a flow thru hemi head and is cam on bucket with adjustable tappets. People look at me funny when I try to tell them about it.
Tony...somewhat off topic, but I see this car has a clear glass fuel filter, of the type that can be disassembled for cleaning...PLEASE remove it ASAP and replace with a metal housing filter. I had a woman with one of these filters on a fake MG with a Volkswagen engine. She complained of a gas odor. I opened the access hatch and a QUART of gasoline poured out!!! The pot metal threads holding the filter together failed just enough to create a leak at the ends, but still passed enough fuel to keep the engine running. She was a frog hair away from a catastrophic engine fire!!!
At 9:15, I think you mean a "runaway condition", also can be called a "positive feedback condition". As an engineer I have encountered runaway failures that need redesign to prevent. Sometimes designers know of an issue but they don't fix as it is expensive, and the issue will not be noticed until later life, so managers say ignore it. A great video explaining this issue. I am amazed on the things I still do not know. Thanks. Cheers Tony!
Those SB Mopars are famous for the passages filling with carbon. My old friend Jim used to soak the passages with diesel fuel and ignite the carbon. It would burn slowly and within a couple of hours clean as a whistle!
People used to do that on the old road draft tubes. They would pull the tube and soak it with gasoline and light it off in order to burn off the blockage. Them tubes could get clogged up and cause the engine to use oil.
My mother taught me my first mechanical lesson in the 70's when trying to warm start her Plymouth: "Put the screwdriver down the hole to open the butterfly valve." Thanks Mom.
Was a dodge dealership in a little town in Virginia called Gretna, when they went out of business one of the mechanics leased the building and ccontinued to service cars that were sold new there, also sold lawnmowers ,weed eaters, chain saws, we used to do tuneups, and preventative maintenance, like putting in timing sets I've pulled many intakes and cleaned out the crossovers, a small chisel would break through it initally, it got easier after that, but I'm with you ,iwould toss that intake and at least go back to a 72 or older that had no egr or electrically assisted choke,which will look more stock
Back in the late 1970's and 1980's I took many intake manifolds off on Chrysler engines because of what you are talking about I would clean the passage in the heads and I would take a small stiff rod and run it through the intake manifold and put the car back together and send it down the road as alot of people in my area had Chrysler products whether trucks or cars and here in southwest pa it gets cold in the winter so they had to have the choke working right!!!!! There was one Chrysler New Yorker 440 engine that wouldn't start one cold day and I took the Tow Truck to this Lady's house and put the jumper cables on it and I could smell ether bad, so I asked her Husband how much ether did you use and he said very little so I started the car and heard a boom and tin rattling and when I looked under the hood it blowed both valve covers off the engine so I towed it to the garage went to the junkyard and got valve covers and put them on and started the car and everything was ok, the car ran great!!!!!!
In the 70s I was the teenage kid in the shop who could actually reach plug#8 in a 440 New Yorker. We patched a lot of tuneups from other shops that skipped #8.... IIRC I still had to pull a motor mount bolt and jack it to reach #8 plug from underneath on the hoist! Aaaah the good old days when cars were "easy" to work on.
Rev the motor up and slam the choke down a few times that might get the idle screws to respond better...I have no clue why this works on a carb but it does. Jamie did it on an Eldlebrock thet other day.
@@oldblueaccord2629 That’s an old trick to clean out power valves or idle passages. I used to call it “back flushing”. Done by reving and forcing choke closed while holding full throttle, then release choke before the engine dies. This uses engine suction to force crud through. Repeat until it seems like it’s running better. As Tony says it won’t do anything for clogged cylinder head crossovers.
Love the scribbles background lore of the ‘cuda! Also sounds like a similar problem on a rule injected Nissan maxima I had with the EGR piping becoming completely clogged. Ran terribly when I got it but it ran better and better the longer I had it!
Never had that issue. I substitute one quart of Marvel Mystery Oil every oil change and put 4 oz of MMO to every 10 gallons of fuel, every fill up, for years, on all my vehicles.
My first car 72 Nova 250 6 3 on tree I put a manual choke on. Pull it as you press gas down once and every time first crank vrrrooom . Funny nobody could start that car without flooding it.Best car I ever had .
Yes, that was a common problem, but mostly a Mopar thing because of their choke functions. You also neglected to mention the other piece of the puzzle, the heat riser valve that makes more of those hot exhaust gases flow through the intake. I just freed one up on an old 318. It also has a thermal spring that opens it up as the engine warms up so you don't boil the gas in the carb. For all of you that think a manual choke is the solution, you don't know how to set up an automatic one properly and you don't know the pleasure of driving a car with one that works as it should.
one of the other reasons it builds up is because of the ruff casting inside the cross over ports . I just plug off the ports and run a manual choke because the factory set up causes the carb to percolate durning the summer from the heat . If people wanted to spend the extra money they can send off the old cast intakes to a place that pumps in a putty with grit in the ports that goes through and cleans and smooths out all the ports . Cant remember the correct name but saw it several years back in a mopar car magazine
Air cooled VW's are very prone to the carb/intake heat runner getting clogged with carbon. Gotta take it out and heat it with a torch, then run an old clutch cable through it while chucked into a cordless drill. Works almost every time!
Another great vid and a very valid topic no one ever talks about. But in my experience working in an automotive machine shop, i have to disagreed that the intake is a throw away. i would chip out the big pieces clogging the entrance ports of the cross-over, remove the splash shield under the intake, then drop it in the hot tank. the intake comes out spotless every time.
@@UncleTonysGarage Like pieces in a puzzle it takes time to put it all together. I knew you had more to come on this so it wouldn't be a 3hr long single video. Keep it coming man. lolol.
Yes, sir I had that issue with a 71 Chevrolet Blazer I bought from a fellow. It has the 307 with the small Rochester 2bbl. I pulled the intake and was able to clean out all of that blockage and the choke works fine. That also helps heat up the carburetor base for proper fuel atomization as you mentioned. And depending upon the humidity the base of the carburetor will sweat and in extreme cold weather it can ice up. People do not realize that the engine is basically aa heat exchanger and heat is energy. Sure, when you are running a race engine or a hopped-up street engine that is one thing, but a regular driver is another. I have two other vehicles which suffer from this malady, and they do not get driven enough to ward off the consequences. I'll get around to dealing with them as well.
Tony, spend your time repairing the rust on the car for when you sell it... Do good quality work through out the entire car. etc etc. I'm looking forward to purchasing that car for a future project. 🙂
Yep! Hand chock. I have tried cleaning that out! Oooo my god what a job. Not a ten minute fix. Good luck trying to find that intake and pull out that card brother! $$$
Love the information never known that or even heard any other mechanic talk about the intake manifold problem like you described and the crossover great information and too saving and old car love it.
We have a very similar problem on old VW Beetles. But there it is not the choke, it is the intake preheat (the Beetle choke element is just a bimetallic spring that connects to the positive side of the coil). The intake is long, and it has a preheat pipe that runs from one side of the muffler, into the center of the intake manifold, and out into the muffler again. With time the tube can get completely clogged with carbon, which can make the intake ice up. Especially in a colder climate like we have here in northern Europe. The fix then is to take the manifold out (it can also be done with the manifold in the car if you remove the muffler) and gently tap the preheat tube with a hammer. Then we take a piece from an old clutch wire, fray the end a bit, and mount it to a drill going counter clockwise. Then it is usually possible to slowly work the cable all the way through the center of the preheat tube from both sides. After the tube is open we can blow out all the loose carbon into a sizeable black cloud. I have no idea if something like that would work on a Mopar manifold. Clogged preheat pipes seems to have become a bigger issue during the later years. People are not driving their cars as much anymore. Also a lot of people are not used to noisy engines, and because of that shift gears way WAY too early. I have heard people say that they think the engine sounds like the pistons are about to come out through the valve covers, while in reality it is barely reaching 2500rpm. One thing these engines are not too fond of is being lugged up hills and only limping around at low rpm. Which makes for both poor cooling and more carbon deposits. Don't be afraid to use the gas pedal. If our old cars are being properly taken care of they can handle it. I liked the choke and manifold that was on the 1961 Rambler Classic we used to have. There the choke was connected to a pipe that ran through the exhaust manifold, and reacted to the heat of the exhaust gases. And the intake was cast into the cylinder head. On top of it there was simply a lid with a gasket under it, and the carburetor bolted directly on top of it. I should probably never have sold the Rambler.
Why not just disconnect the auto choke and hook up a manual choke cable?
Watch the next video...I made it for you
the guy is pissed off with that history
Exactly. Wins dumb big😂
👍💕
That's what I always did
When I worked at a Dodge dealership in the 70's and early 80's, plugged crossovers was a common problem. On Chrysler products, the crossover has to be open and the exhaust damper has to function correctly or the choke will never fully open. We cleaned many intake manifolds and rebuilt many exhaust dampers. It seemed to be worse on the newer engines with EGR. A rule of thumb was that if you touch the intake around the choke with a fully warmed engine, it should leave a little skin.
Years ago, when I started off in an engine machine shop, I had to tear down the engines to be prepared for overhaul. I know exactly what Uncle Tony's referring to when
It comes to those passage ways basically becoming a black diamond. I Would just toss them in the big oven and literally bake
them overnight @ 750⁰. When I came in the next morning they would be still pretty warm. Then the carbon just basically turned to powder. So it's not real bad to clean them but still a pain. Thanks for sharing!
Tony gets it - it's the *stories* that go along with each and every one of these old cars that
make them matter, make them interesting, make us love them.
The history of each are what makes this a true hobby.
- Ed on the Ridge
Peoples upgrades are other peoples ruins.
Most of us, in those days went to manual control. It only cost $2 and solved the problems. In 1970, I took apart a choke on a '63 Chevy 283 that had been assembled backwards at the factory(choke off when cold and choke on when warm) or sabotaged at the dealer. Ten minutes and it was working fine. Good Luck, Rick
I was going to say the same thing. Put a manual choke on it, and keep on going
First sentence: Exactly. Conversion to manual choke was a simple fix for a clogged crossover and/or an iffy auto choke.
My late father was a mechanic back in the day and I remember him telling me that most of his customers who tried manual choke conversions were not happy with them, and asked to return back to automatic. Granted his customers were not "car guys" who are more receptive with returning to the slight inconvenience of an old school hand choke.
@@kentjohnston2582 Yeah but that dont sell videos.
I had a 62 Chevy 2 in 1998 with straight six (no chock at all) on cold day just pump gas twice crank right up. Hot day just turn the key. It would idle all day without skipping a beat.
If I had a dollar for every hour I've spent chiseling carbon out of Mopar manifolds, I think I could buy another old Mopar. Then I could spend more time knocking carbon out of that one.😆
UT, I'm glad to hear about keeping the cars history intact. The scribbles ARE part of the cars life story. I have a 58 year old, inaccurate tach mounted with an exhaust clamp by the original owner of my cherished 1965 GTO. I'm also leaving it as part of the cars history and nod to the original owner.
I love neat stories like this, thank you for sharing
Thank you for your kind words. The GTO has bumps and bruises everywhere, each with a story and I know them all. See NYS-GTO @@arindryn0:04 0:04
Barefoot gas pedal. My dad had an uga horn that went from his 59 Ford to 72 gran Torino to somewhere in my garage.
That intake may have been a throwaway 40 years ago, but not today. It is NOT that hard to clean out the hardened carbon. I’ve done it on three 318s and it isn’t that difficult. But it makes a massive improvement in driveability.
Gas was dirty till fuel injection made the show and fuel companies had to do better.
I remember back in the 90s watching my dad do the same thing with a infrared thermometer that looked like a space laser. He used to tune carbs by header temp and smell. Really glad you're putting this info out there as these seem to be the more arcane tricks most people don't know.
Ahh the space Lazer, here I thought we would get cooler tools in the future to work on our cars but instead we CANT work on our new cars
@@redlight3932, you Can still work on your cars..... just get out the credit card, spend about $6,000 on bidirectional scanners, oscilloscope, good meters. Then watch Eric at South Main Auto. If he can do it, then you can do it ! ! !
There... problem solved !
I blocked off the exhaust crossover on my ‘70 Charger with the aluminum Edelbrock Six Pack manifold. Worth a few HP, and then installed a manual choke.
This and the previous video is why I love this channel. You’re the best, Uncle Tony.
Manual choke even easier than finding a new manifold. A small four barrel makes it run so much better even if you arent looking for more power. I had the same setup on my old 318, threw away the stock carb and replaced with a junkyard Edelbrock . It ran better at idle, started easier and had more power. I get keeping things stock but sometimes its just too stupid to do.
Agreed, manual choke all the way. And I blocked off the crossover on my manifold to keep the intake temps cooler, though I wouldn't recommend doing that unless you have a crossover pipe on your dual exhaust.
@@JB-xg7ioGenuine question here, why would it not be reccomended to block off intake crossover without having an exhaust crossover pipe?
As I understand it, 4 barrels could be slightly more efficient than twos as long as you’re not flooring the gas pedal every chance you get. Having gotten my license in ‘75 I try accelerate smoothly and anticipate stops by letting up on the gas.
Had that exact problem, solved with a manual choke cable, easy peasy.
Yeah. Me too.
And I wish I had 10¢ for every mile I drove with the choke left on.
RIght on! I stopped messing with automatic chokes back in about 1982 and have never looked back.
I did the same
@@outlawbillionairez9780 My old Volvo had a blue light that came on when the engine was warmed up that said choke.It went off when you pushed the choke knob all the way to off. Engine never fail to start with a manual choke.
A manual choke will solve a symptom, not a problem.
My '71 Fiat 124 had a factory manual cable choke. It worked perfectly. All my old motorcycles have manual chokes. Its somehow more satisfying when you have to interact more with the machine.
Having worked as a Emission/driveability tech back in the the day i ran into this problem a stuck heat riser valve in the exhaust was a major player in this i dont know how many of those i have replaced but it was a lot ! keep up the good work Tony !!
Back in the day I cleaned out dozens of 318/360 heat passages on those things. Being in Canada, at -30f i did about 6 a week. I have seen the whole carburetor frost up, inside and out, especially when it was humid and cold, with the complaint "it keeps stalling" or won't idle when it's cold and damp.
That alternator belt is loose. I solved the choke problem on my cars. I removed the damned things. I live in Phoenix, AZ, where chokes are not needed. Pump the pedal a couple of times, and the engine will start right up. I always warm up the engine before taking off. I have never believed in putting a load on a cold engine. EFI is more than 10 times more complicated than a carburetor, so there are a lot more things that can and do go wrong. The last several years I worked as a professional mechanic for a large government fleet department, I had to deal with thousands of check engine lights. Automatic chokes have always been an issue, but they are a simple and easy problem to get rid of. Either get rid of the choke altogether, or use a manual choke.
Stuck a manual choke on my '69 340. Solved. Now if I could only keep the eddy's fuel bowls from evaporating away after the car sits it would be perfection.
Back in the day we'd cut up a coffee can to create block off plate for the crossover passage in order to keep the fuel/air charge cooler. Our Holleys had manual chokes anyway.
Someoe mentioned using a manual choke, good idea. I like being in control of such things!
I always ran a manual choke when I blocked off the heat riser on a hot rod
"a vicious circle" The algorithm brought me here after the previous video you mentioned. Thanks again.
I was going to say, "viscous cycle," but it's the same thing.
Very true about blocking any manifold heat for an engine that will see a track. Cooler air is denser, which means more power, and in racing, you want to WIN by an inch, not lose by an inch. On a street engines, you WANT manifold heat, as a warm manifold means a stable air/fuel charge - in the winter, the gas will tend to fall to the walls of the manifold at lower speeds until you have been driving for quite awhile.
I ran into that with a 283 years ago. As it was my daily driver and already had an old wore out Rochester 4GC four barrel carb, I did the street aluminum intake and a 390 Holley w/ vacuum secondaries along with a manual choke. Problem solved, the Nova ran great and got good mileage. Those old 4GCs at that time were very hard to find, which is why I went with the Holley.
This is why I always use a Manual Choke and completely despise an "automatic" choke and I'll go so far as to say that 90% of all classics you get your hands onto will have this issue.
A machine shop can knock out that cross-over and it's not that bad on price, but it's included in all the rest of the bill when we take them an engine to make ready for assembly.
Good stuff as always UTG.
I once came across this fellow having trouble with his "hot" "63 Vette. He installed a rebuilt engine but could not get it to run cool around town; on the road OK but otherwise ran hot. Spending days on his problem, he changed the water pump, radiator, thermostat etc but no help. Showing me the problem, he started it up cold and within a short period, the engine was radiating so much heat, you had to back away from the engine. Looking down at the exhaust manifold, I spotted the heat riser and saw that it was installed upside down so as the engine warmed up, the exhaust gases increased into the intake manifold cross-over...
Scribbles on the gauges...perfection. I agree, it fits the car and is part of its history.
Kathy is waiting for this car to be done so she can drive it. Tony is taking his time.
Tony's probably trying to get her to fall in love with XJ's so he can buy more😂
Shelve that manifold with other antiques. Check the head ports place a performer manifold and carb. Yes I know it's a daily driver. But this engine deserves it make it happy!
@@harlyjock1 I've cleaned several of those passages out. It's no big deal. Stock stuff worked just fine. It'll work fine again.
@@outlawbillionairez9780 and fix the exh. manifold damper too.
@@oscaracme because I'm extremely old, I worked on these cars when they were not really old. Every choke had a problem, and every exhaust butterfly was rusted in place. And this was Southern California. People ran water, not coolant, so every old car had freeze plugs rotted out. All the new emissions required stuff like air pump and hoses fell apart. No matter what Tony says, these weren't the good ole days. Glad they're gone. ☮️
318s and 360s were terrible for that. I have done countless de-carbons on those, usually having to use chisels and old screwdrivers to chip out the coal-like carbon. Don't miss those days.
Uncle Tony, in the late 80's and early 90's i cleaned alot of those intakes. Theyd give those crappy jobs to the kids in those days! Manual choke is way easier 😅 Cheers from Junk's Automotive Indiana USA
Yep . As I recall , they were called Heat Risers ? Along with what you mentioned , the cold bottom of the manifold doesnt help vaporize the fuel / air mixture beforehand . When guys ask me what I like best between carburation and electronic fuel injection ? I say that each has a purpose for a given situation ...that avoids the argument . Using the Jeeps , the cars were limited off road . If the hill was too steep , the carb worked against you due to the float . Injection has no such problem .
Uncle Tony…..I cleaned the carbon on intakes when I was just starting out in a Dodge dealership. You remove the intake and heat the passage blocked with carbon with the acetylene torch, then turn off the gas and blow the oxygen on the carbon to accelerate the burn. It does smoke and stink up the shop, but they come clean as new. Working on cars 45 years ago was more enjoyable! Another quick tip: If you can hold your finger on the choke stat longer than the count of 3, it’s too cold 😳
I have a 1970 truck 318 in my Barracuda that has a water passage under the carb, rather than exhaust gas, so i had to go manual choke. Best part, its a forged crank w/ sodium valves!
Amc with the 2100 and 2150 carbs. Have a plate bolted to the side of the choke thermo spring with those black housings. That plate holds the heatercore hose directly from the intake/thermostat housing area. So this helps heating the choke up very quickly.
With this. Ive never had issues running my 360s with rusted out broken heat tube risers on the intake. It heats up very quickly within seconds.
Those heat riser tubes under the carb in the intake . Also helps create vapor lock. Some guy will take the intake off and block it off to fix vapor lock
That style choke uses a 12V wire to operate in addition to heat provided by the exhaust crossover in the intake manifold. There is a heating element next to the bimetallic spring that operates the choke. The post is still there, and the wire is broken off. A switched 12V power source will open that choke.
good catch !
Honestly I only have ever had electric chokes. Some of them have provisions for exhaust gases and whatnot but I have not heard a convincing argument to use one. Only potentially annoying part of an electric is if you leave the key on and the car off (rare occurrence).
I’ve never seen a carter bbd with an electric choke. Ever! Please tell us just what car had a carter bbd 2 barrel with an electric choke element in it.
@@davidleonard83696:07
@@davidleonard8369 That's not the carb that came on that manifold. The intake and possibly the engine are out of a later model car. Then someone put the older carburetor on it.
I love these "basics" videos! It's stuff I don't know, or have forgotten.
On these cars & all the ones I've owned that had carbs, I used a manual choke-always. No problems. If it came with an automatic choke, it was switched to a manual. It's not that hard to do. But your video is right on the money.
maybe it has Intake Gaskets that are blocking that passage off.
Previous owner could have also blocked them off on purpose, thinking, like Tony said, that it would make more power. Doubtful, but teenage boys will try anything for easy horsepower. I put split fire sparks plugs in my firebird when I was a kid. I believed I could feel a difference… 😂
@@met454 Any you could. In your wallet but not in the car
Looks like a new camera or uncle kathy playing with the lighting in the editor.
Nice! Looks good guys, nothin but gratefulness for basically free content!
I'd forgotten about having this problem back in the sixties. In every case, they were big sleds that never saw 3500 rpm or full throttle.
With the cast iron intake manifolds, I could always fire up the torch to get the carbon out of it. It makes lots of fun sparks, too. Just do it outside, the hell away from everything else. Use appropriate shielding or do the hot ember dance. The aluminum manifolds weren't as easy.
Awwww!!!! I can see you have a soft spot for the kiddos, Uncle Tony!!! Right on man!!!!
Great video and great explanation, I just install manual chokes on my old cars.
Kinda off subject kinda on subject.
My son once wrote I love Dad inside our china closet , My wife discovered it and showed it to me and asked what we should do. I said nothing that’s awesome!!
The previous owner of my ‘41 Chevy tied up the broken end of the windshield wiper with a bit of string. This truck never sees the rain, so I have left the wiper and string as is. It’s part of the truck’s history.
Tony, I had a 360 in a '74 Ramcharger that would turn the carburetor into a block of ice. It actually would build up 3/8" of ice in the summer... until the intake was changed. I could warm it up and shut it off for about 15 Minutes and the block heat would thaw out the carb. then it was pretty driveable.
Neato!
Explains why my mechanic 35 years ago said I had to leave it overnight for a diagnosis. I started a different comment until you explained the conflicting advice to plug the heat crossover.
10:05 When you swap it out will you show us the carbon build up? I'm not a mechanic and I'd like to see it. Thanks.
When I was a teenager and the only dirt bikes were 2stroke and when they gummed up the exhaust badly with carbon and I can't remember what we used to soak out the carbon buildup in the pipe because as teens no one had any money to buy anything but gas and Tyres 😅
Gold wing. ! You lucky dog . Has jar took a ride yet . Remember she is a big part of the uncle Tony saga !
What about the adjustment on the choke pull off rod? It should be able to open the choke fully after a few blips of the throttle. In the summer you just need the choke to start not to stay on.
I once had a plugged intake manifold from a 2 barrel 318 hot tanked in a bath of chemicals for a few hours and came out spotless. Simpler than changing the whole intake.
Ford small blocks PUs had the same problem. One of the secrets of small block Dodges PUs was keeping that passage clean.
I daily an 86 Nissan D21 with Z24i engine. I have hot start issues. The tbi seems to be over fueling on hot restarts. I know it could be a few things I just wanted to share some of the weird stuff. The coolant runs through the tbi and it has a wax pellet choke. It has duel sparkplugs with a flow thru hemi head and is cam on bucket with adjustable tappets. People look at me funny when I try to tell them about it.
Tony...somewhat off topic, but I see this car has a clear glass fuel filter, of the type that can be disassembled for cleaning...PLEASE remove it ASAP and replace with a metal housing filter. I had a woman with one of these filters on a fake MG with a Volkswagen engine. She complained of a gas odor. I opened the access hatch and a QUART of gasoline poured out!!! The pot metal threads holding the filter together failed just enough to create a leak at the ends, but still passed enough fuel to keep the engine running. She was a frog hair away from a catastrophic engine fire!!!
Yeah, I hate those filters. And they clog up easy too with very little filtering area. Course, you can blow them out, if you like the taste of gas,
At 9:15, I think you mean a "runaway condition", also can be called a "positive feedback condition". As an engineer I have encountered runaway failures that need redesign to prevent. Sometimes designers know of an issue but they don't fix as it is expensive, and the issue will not be noticed until later life, so managers say ignore it.
A great video explaining this issue. I am amazed on the things I still do not know.
Thanks.
Cheers Tony!
When you find another intake manifold do a video of the carbon build up inside the heat cross over Uncle Tony.
Yeah I gotta see this.
Check the heat riser valve also!
Only thing I would do is fix the rust issues and drive it. It’s definitely a cool old car!
Manual choke, problem solved. I always run manual chokes.Manual choke kit, $20, New /Used intake $80-140.
If the intake passage is clogged, so are the passages in the heads! Just changing the intake won't resolve that.
This is the material that makes this channel interesting. Tony is a great teacher of old moparology
Love how you got your name for Scribbles!
Those SB Mopars are famous for the passages filling with carbon. My old friend Jim used to soak the passages with diesel fuel and ignite the carbon. It would burn slowly and within a couple of hours clean as a whistle!
People used to do that on the old road draft tubes. They would pull the tube and soak it with gasoline and light it off in order to burn off the blockage. Them tubes could get clogged up and cause the engine to use oil.
My mother taught me my first mechanical lesson in the 70's when trying to warm start her Plymouth: "Put the screwdriver down the hole to open the butterfly valve." Thanks Mom.
Was a dodge dealership in a little town in Virginia called Gretna, when they went out of business one of the mechanics leased the building and ccontinued to service cars that were sold new there, also sold lawnmowers ,weed eaters, chain saws, we used to do tuneups, and preventative maintenance, like putting in timing sets I've pulled many intakes and cleaned out the crossovers, a small chisel would break through it initally, it got easier after that, but I'm with you ,iwould toss that intake and at least go back to a 72 or older that had no egr or electrically assisted choke,which will look more stock
Back in the late 1970's and 1980's I took many intake manifolds off on Chrysler engines because of what you are talking about I would clean the passage in the heads and I would take a small stiff rod and run it through the intake manifold and put the car back together and send it down the road as alot of people in my area had Chrysler products whether trucks or cars and here in southwest pa it gets cold in the winter so they had to have the choke working right!!!!! There was one Chrysler New Yorker 440 engine that wouldn't start one cold day and I took the Tow Truck to this Lady's house and put the jumper cables on it and I could smell ether bad, so I asked her Husband how much ether did you use and he said very little so I started the car and heard a boom and tin rattling and when I looked under the hood it blowed both valve covers off the engine so I towed it to the garage went to the junkyard and got valve covers and put them on and started the car and everything was ok, the car ran great!!!!!!
In the 70s I was the teenage kid in the shop who could actually reach plug#8 in a 440 New Yorker. We patched a lot of tuneups from other shops that skipped #8....
IIRC I still had to pull a motor mount bolt and jack it to reach #8 plug from underneath on the hoist! Aaaah the good old days when cars were "easy" to work on.
Rev the motor up and slam the choke down a few times that might get the idle screws to respond better...I have no clue why this works on a carb but it does. Jamie did it on an Eldlebrock thet other day.
What on earth could that possibly have to do with a cold intake manifold?
@@UncleTonysGarage I think it help with setting the idle screws....I guess not.
@@oldblueaccord2629
That’s an old trick to clean out power valves or idle passages. I used to call it “back flushing”. Done by reving and forcing choke closed while holding full throttle, then release choke before the engine dies. This uses engine suction to force crud through. Repeat until it seems like it’s running better. As Tony says it won’t do anything for clogged cylinder head crossovers.
@@UncleTonysGarage So it was the carb not the intake...huh? who woulda thought.
Love the scribbles background lore of the ‘cuda! Also sounds like a similar problem on a rule injected Nissan maxima I had with the EGR piping becoming completely clogged. Ran terribly when I got it but it ran better and better the longer I had it!
Never had that issue. I substitute one quart of Marvel Mystery Oil every oil change and put 4 oz of MMO to every 10 gallons of fuel, every fill up, for years, on all my vehicles.
Never have I EVER heard this exhaust carbon buildup being an issue for choke issues. Thank you.
That's a big temperature difference. I like how you use a fancy digital IR thermometer to pin point an old problem. I look forward to the fix.
We need more people who think like Tony. Keep it original.make it work as intended.
Add a manual choke knob to pull it open..
My first car 72 Nova 250 6 3 on tree I put a manual choke on. Pull it as you press gas down once and every time first crank vrrrooom . Funny nobody could start that car without flooding it.Best car I ever had .
Yes, that was a common problem, but mostly a Mopar thing because of their choke functions. You also neglected to mention the other piece of the puzzle, the heat riser valve that makes more of those hot exhaust gases flow through the intake. I just freed one up on an old 318. It also has a thermal spring that opens it up as the engine warms up so you don't boil the gas in the carb. For all of you that think a manual choke is the solution, you don't know how to set up an automatic one properly and you don't know the pleasure of driving a car with one that works as it should.
one of the other reasons it builds up is because of the ruff casting inside the cross over ports . I just plug off the ports and run a manual choke because the factory set up causes the carb to percolate durning the summer from the heat . If people wanted to spend the extra money they can send off the old cast intakes to a place that pumps in a putty with grit in the ports that goes through and cleans and smooths out all the ports . Cant remember the correct name but saw it several years back in a mopar car magazine
Thank you for this! My 62 Bel Air which is a 235ci has this exact problem and was struggling to figure it out.
Air cooled VW's are very prone to the carb/intake heat runner getting clogged with carbon. Gotta take it out and heat it with a torch, then run an old clutch cable through it while chucked into a cordless drill. Works almost every time!
i know someone with a motorhome with the same symptoms, ill have to go back and see if this is whats going on. thanks tony
Another great vid and a very valid topic no one ever talks about. But in my experience working in an automotive machine shop, i have to disagreed that the intake is a throw away. i would chip out the big pieces clogging the entrance ports of the cross-over, remove the splash shield under the intake, then drop it in the hot tank. the intake comes out spotless every time.
It's a throwaway because it's an extremely undesirable intake manifold. Not worth the effort to save it
@@UncleTonysGarage I'm going to try to follow suit and replace my 318 intake as well!
Dear god please check the heat riser valve before removing the intake manifold.
You caught that too? That is something most people miss as well.
And the thermal spring on them is adjustable as well.
The heat riser only works for the first minute or two after the engine is started. After that's it's open and does nothing.
@@UncleTonysGarage Like pieces in a puzzle it takes time to put it all together. I knew you had more to come on this so it wouldn't be a 3hr long single video. Keep it coming man. lolol.
But they will rust open or closed.
@@bobbybrown931 the plate can rust out or fall out and it’s not uncommon for people to just remove them. And I’ve seen plenty of them stuck open.
Maybe the intake gaskets are not correct and block off the passage. You have to do an autotopsy.
I love the scribbles! I would pay extra $$ to buy something with that personality.
Much love
UT and UKB
Would you now? I got a grandaughter with plenty of crayons!
Yes, sir I had that issue with a 71 Chevrolet Blazer I bought from a fellow. It has the 307 with the small Rochester 2bbl. I pulled the intake and was able to clean out all of that blockage and the choke works fine. That also helps heat up the carburetor base for proper fuel atomization as you mentioned. And depending upon the humidity the base of the carburetor will sweat and in extreme cold weather it can ice up. People do not realize that the engine is basically aa heat exchanger and heat is energy. Sure, when you are running a race engine or a hopped-up street engine that is one thing, but a regular driver is another. I have two other vehicles which suffer from this malady, and they do not get driven enough to ward off the consequences. I'll get around to dealing with them as well.
Outstanding information Tony. I'm dealing with a 76 gm 250. What a pain in the arse it has been.
Manual chokes were so much better. For many years, I would reach for the choke, automatic chokes sucked.
Perpetual motion is the thing chasing it's own tale.You are talking about that keeps motion going on its own.My grandfather had it figured out
I put manual chokes on my 68 and my 74 Plymouths back in the day. My brothers 65 Econoline came from the factory with one.
every day we learn something new, old school style,,,
Tony, spend your time repairing the rust on the car for when you sell it... Do good quality work through out the entire car. etc etc. I'm looking forward to purchasing that car for a future project. 🙂
Tony has no clue how to do proper body work. Hes a hack when it comes to that lol.
I couldn't find books in the library to help me with these problems. Now we have youtube.
Yep! Hand chock. I have tried cleaning that out! Oooo my god what a job. Not a ten minute fix. Good luck trying to find that intake and pull out that card brother! $$$
Love the information never known that or even heard any other mechanic talk about the intake manifold problem like you described and the crossover great information and too saving and old car love it.
Thanks Tony
Not an issue on any of my classics as they have SUs with manual chokes, but I sure appreciate the information. Thanks.
THIS, is why I’m here.
We have a very similar problem on old VW Beetles. But there it is not the choke, it is the intake preheat (the Beetle choke element is just a bimetallic spring that connects to the positive side of the coil). The intake is long, and it has a preheat pipe that runs from one side of the muffler, into the center of the intake manifold, and out into the muffler again. With time the tube can get completely clogged with carbon, which can make the intake ice up. Especially in a colder climate like we have here in northern Europe. The fix then is to take the manifold out (it can also be done with the manifold in the car if you remove the muffler) and gently tap the preheat tube with a hammer. Then we take a piece from an old clutch wire, fray the end a bit, and mount it to a drill going counter clockwise. Then it is usually possible to slowly work the cable all the way through the center of the preheat tube from both sides. After the tube is open we can blow out all the loose carbon into a sizeable black cloud. I have no idea if something like that would work on a Mopar manifold.
Clogged preheat pipes seems to have become a bigger issue during the later years. People are not driving their cars as much anymore. Also a lot of people are not used to noisy engines, and because of that shift gears way WAY too early. I have heard people say that they think the engine sounds like the pistons are about to come out through the valve covers, while in reality it is barely reaching 2500rpm. One thing these engines are not too fond of is being lugged up hills and only limping around at low rpm. Which makes for both poor cooling and more carbon deposits. Don't be afraid to use the gas pedal. If our old cars are being properly taken care of they can handle it.
I liked the choke and manifold that was on the 1961 Rambler Classic we used to have. There the choke was connected to a pipe that ran through the exhaust manifold, and reacted to the heat of the exhaust gases. And the intake was cast into the cylinder head. On top of it there was simply a lid with a gasket under it, and the carburetor bolted directly on top of it. I should probably never have sold the Rambler.
To keep the choke functional i have only blocked off the drivers side crossover.
Nicely done. 😊
Welcome Scribbles!