How to Adjust Edelbrock Air Valve Secondaries (AVS)
ฝัง
- เผยแพร่เมื่อ 30 ก.ย. 2024
- I’ll show you how and when to adjust the air valve secondaries (AVS) and one massive mistake everyone seems to make when setting this adjustment. Its not complicated and actually one of the easiest adjustments you can make, but getting it wrong just makes the tuning process longer.
Carburetor - amzn.to/3doGmtK
Calibration kit - amzn.to/3lBVZCE
Pressure regulator - amzn.to/3lJo2NB
Cheaper pressure regulator - amzn.to/3glXxNi
Edelbrock fuel line kit with filter - amzn.to/2JD5vFL
Edelbrock fuel line kit w/o filter - amzn.to/2JRNweB
10 micro filter - amzn.to/2JLx53j
100 micron filter - amzn.to/36LwiIJ
Liquid filled gauge - amzn.to/3mLPfRa
Wood laminate spacer - amzn.to/2JOtoKm
Phenolic spacer - amzn.to/2JMBPpo
Mr Gasket base gasket - amzn.to/2LjIUi1
My new website - musclecarsolut...
Order My Merch Here - muscle-car-sol...
I'm on Instagram! - / muscle_car_solutions
Wanna buy me a beer? ;) I like beer! / musclecarsolutions
New video cam! - amzn.to/2RkHUJe
Gimbal - amzn.to/2wg8Sbc
My Amazon Store - www.amazon.com...
#edelbrock #avs #secondaries
Exactly! People forget that air accelerates faster than fuel, so when you whack the throttle open the engine usually takes a big gulp of air because it's physically lighter than fuel and gets to the intake valve before the liquid fuel does. Slowing down the AVS valve slows down that acceleration of the air so the engine doesn't hesitate, and it has a chance to pick up fuel thru the boosters.
hello sir i just purchased one of these avs2 and it does fine until i’m at the end of my gear it starts stuttering at the end of every gear i have a manual transmission
If I have a carb backfire when jumping on the throttle will this adjustment resolve that issue?
It’s possible. But there’s some other factors at play. Fuel pressure and level in the carb, timing.
@@MuscleCarSolutions I ordered a new vacuum advance can for it for a start. Then I’ll do timing also when new can is in.
The wealth of knowledge you're sharing is just over the top. Thanks again for a great video!
I literally know nothing else. Just ask my wife! 😂 Thanks man! Happy holidays!
@MuscleCarSolutions do you think these 650 versions would work with a 355 smallblock that only produces 9hg in vaccum at idle? It has a howards rattler hydraulic retro fit roller cam with 227 duration @50 intake and 235 at exhaust. 109 lobe separation. It's a daily driver and I was really considering one of these avs2
Love your videos!!! Makes me feel confident to work on my AVS2. I dont want to go to EFI just yet.
They’re easy. Lots of resources here to help you. Get the fuel system right and tuning a carburetor and ignition becomes very easy.
@@MuscleCarSolutions i want to install a wideband o2 sensor next so I can tell exactly if im tuning it right.
Always a good choice. That’s a tool you’ll come wonder how you ever did without it! Makes tuning much quicker.
Thank you for your videos, you made fine tuning my carb easy and understandable, my truck is running great now !
Nice! Glad it helped!!
Everything I've learned about fine tuning my carb and engine. 98% of it has been from your videos.
Nice! I hope we got it running right. 😂
same this guy has been so helpful for a young guy like me learning all this stuff
To tighten the spring you say counter clock wise. Edelbrock states clockwise? Just want to be sure. Thanks!
Tighten the adjuster screw to make the spring weaker. Loosen the adjuster screw to strengthen the spring. It's obvious when you see it.
I'm glad I came across your videos about a year ago, definitely learned alot got a Holley double pumper on my 396 Edelbrock 800 thunder series on my old 454 and a street demon on my 402 GMC maybe a video sometime on the street demon thanks again who needs TV when we got your videos lol
Nice! I’m glad they’ve been useful! I don’t see the demon carbs that often. Might be because I’ve just gotten a reputation for fixing Edelbrock’s. Next time I get one, I’ll see if I can get permission from the owner to shoot a video. Appreciate it! Happy holidays!
This carb, avs2, is a no brainer for me. Back in the day I had a new 71 340 Duster which I would run against a racing friend, with a 70 Nova 350, from a kick. He always got me by 1 1/2 cars, time and time again. I didn't know anything about tuning a carb, until reading an article on my Thermoquad. So I did a rod change and adjusted the door until I could feel the motor wanting to pull, while flat out. Making it stiffer causes more velocity !
The next time I got him by 1 1/2 cars. The TQ was rated at 800cfm, so this 800 AVS2 will work on my 70 360, and it's stroked. So I will have my TQ back, plus annular boosters !
Information is power, so thank you ! As the song goes, Still crazy after all these years !
Good stuff as always! I had heard before that you could make adjustments on a carburetor without a hammer…who’d have known it’s true!
Sometimes a hammer is all you need!
Thank you, I just put a 650 AVS2 on my fresh built 383 and have that hesitation for 1 second , when cruising 40mph and hitting the gas pedal hard. This should get me past that.
It can! Let me know if it doesn’t fix it.
@@MuscleCarSolutions I still have a hesitation after 3/4 turn counterclockwise.
Yeah, thanks for the invitation to contact you, I will be rebuilding 2 Holly 450s for my car. In 3 to 4 months time.thanks
Easy!
Sounds like playing around with the old Q-jets, always great videos.
Happy and Safe Holidays to you and yours 👍👍😎
Appreciate that! Happy holidays to you as well!
I need the 4300 squrter. Been trying over 7 months and nobody has them
How do you know you need the 43 squirter?
I know that old blue truck is happy with his new owner!! Old blue is running better than he ever has ! 😁
She’s running about as well as she’s going to. She smokes pretty good after sitting for a fee days and is burning oil. She’s ready for a rebuild for sure. Sometime this winter or early spring.
Ok im glad i found this video .
I have a 1965 283 with stock rebuilt powerpacks that i had z28 springs installed as well as hardened valve seats, it has a 327 intake . Edelbrock avs2 500 cfm on it , and a msd streetfire dist . Its in a 83 s10 chassis with a 1951 chevy 3100 on it with a th350 w shift kit and Ford 9 inch 3.25 final drive. Weighs roughly 4300lbs im told.
When i stomp on it to pass, doesnt seem like the secondaries are doing anything. Where would you start looking to adjust? Just a street application but i live on top of a 1300 ft mtn in north alabama . Access roads are steep.
@@charlespartak2435 I have more questions than answers. What intake is the carburetor bolted to? (Potential vacuum leak). What is your initial timing and when is your full timing and ya what rpm does it come in at? What step up spring color are you using and what is your engine vacuum at idle? I’m assuming you watched the video and have made adjustments to the secondaries? Did you tighten the spring or loosen it? “Feeling” the secondaries arent doing anything isn’t helpful. Do you feel that when you hit the gas hard it stumbles or hesitates? Or are you expecting some big snap in power than you aren’t feeling? The secondaries open when they are told to and the transition isn’t meant to be some violent occurrence, if that’s what you’re expecting. It’s generally a smooth transition to the fuel metering through the secondary boosters.
@@MuscleCarSolutions 3872788 is the intake.
No vac leaks, steady vac gauge needle.
Ill admit now, i had the dist vac pot hose on manifold vac on front. Just swapped to timed port and adjusted the rear sprung butterfly to looser , its not flapping but easily moved ..if that makes sense. I took the screw loose that covers the top needle pistons and they arent jumping out of the holes, they sit about 1/16" below flush . But a hand throttle blip theyll jump a little . No tach so dont know rpms. I just know when ive asked it for more accelerator, it says , Huh ? Ill take it for a spin after these changes and see how it does.
Great information as always!!!!
Thanks man! Appreciate it!
How are you doing?
Thank you for breaking it down, I messed with everything else except that. Lol 85 Monte with 350 running like a champ 🏆
Do all avs2 carbs have the annular primaries? I am considering a 1913. Thanks
@@garrettbenson7743 annular primaries
@@MuscleCarSolutions yes. Sorry. Primaries. Is it worth it over performer?
@@garrettbenson7743 I believe so. The throttle response on the annular carburetors is well with making the upgrade. Plus the adjustable secondaries is a big upgrade over the performer series carbs.
Thank you for providing this, I was thinking about this method after getting a bad and consistent bog when getting into the secondaries. This is gold and you explain this very well! I have a pontiac 455 and the Holley was just something I didn’t know much about and bought a avs2. The response and acceleration is great, but when I punch it or go into the secondaries it bogs very bad and seems like it stays that way until I get off.
Cool! Was hoping this would be useful to some folks. Thank you!
How did it work out for you?
Hello my friend I just wanted to give you a heartfelt thank you for taking the time to make such a great video. I have a 351 Windsor in a 1966 F100 and I'm in the process of getting her tip top again it's sat for long periods of time over the past 13 years. The power plants only has 8,000 miles on it but at this point I've replaced the distributor battery alternator I just blew all the seals out of the carburetor new accelerator pump so on and so forth. I went with the AvS 2 I have it up and running again. I'm struggling with the timing but I understand I need that right first before dialing in the carburetor. I purchased the spring kit since she has the biggest cam possible for stock heads definitely a nice in her idle. Anyways thanks again for such a great video this is top quality for sure. You are the man.
Nice! Thank you! I’m a big fan of the Windsor engine. Cant wait to build another one. Have fun with your truck and if I can help with any of your tuning questions don’t hesitate to ask! 👍
If you could what would you recommend I learn from to become the great master of stabbing distributors and getting my timing on point?
The most difficult part is getting number 1 to TDC. Plenty of good tools for that to make it easy. Everything else is pretty easy to get the rotor lined up and you’re ready to fire!
edelbrock bought the rights for q-jets an started making these cheap knock offs , imho a q-jet is the better carb , having said that your video should cure most bog issues with these carbs and after you have spent an hr or two adjusting testing adjusting an get it spot on can pat yourself on the back for learning something about tuning 🙂 Good vid
The same applies to the thermo bog. People usually adjust it lighter and end up w the bog. Stiffen it and it goes away. Good explanation.
I think that slowing down the door from opening allows the air to move faster, into the carburetor for a longer period of time. Better suction.
Like when you put a smaller diameter hose attachment on
a shop vac , it sucks harder than a larger diameter hose.
Is that the reason you said that you start by slowing down the door instead of speeding it up at first attempt ??
A few months ago I purchased a 625 street demon carb, and it's basically the same design. But for the life of me I can't tune out that lean stumble. When I stab it to the floor, it's fine if I roll into. Nothing seems to fully cure it, even tried 3 jet changes. Any ideas on this carb? From what I read it's pretty common. Thanks!
I went ahead and bought a 1905 (electrical choke suck on hot cars) and wouldn't you know it I'm right back to Muscle Car Solutions because I have the exact problem you're talking about. I sound like a broken record but once again thank you. On a side note I checked your website for an 1905 or 6 for a while but I just couldn't wait any longer, although the 600 CFM Holley Street Warrior on your website did intrigue me. The deciding factor to go with an Edelbrock was actually when you told me something along the lines of if you want the sound of a Holley idol just make a vacuum leak. You are a funny man and I'm here for it!
Good deal! You’ll love the throttle response of that AVS2! Thanks again man. Appreciate it!
Is there a bench setting for that. Secondary door. Look like you went to a quarter turn on there. Mine was like 2 whole turns.
Just like the old carters , so easy , so many people throw them away for that reason and I pick them up for almost free at swap meets and run them .
Design taken directly from Rochester.
Great teaching videos. I’m finally accepting other carbs as good or better than a quadrajet! Lol yes, I was one of those guys relieving spring tension, instead of increasing. Took lots of runs to finally just accept that I was backwards lol. Thanks for great vid.
@@clean1566 it’s situational. Put the right carburetor in the right situation and you’ll get a good, repeatable result. I’ll always be a Qjet fan. But I know it’s not the best in every situation and there’s other carbs to fit in that spot. Glad you got the AVS adjusted! Makes a big difference.
Does this fix my high idling?
No. Idle issues are handled with the idle circuit and the fast idle cam.
A question for you kind sir.
On my mild 318 (just a small cam) stock heads,edelbrock intake and a complete exhaust system and running 3:45 gears in the rear,carby is a edelbrock AVS 500 which was professionally tuned and runs great! now I have no bog or hesitation when cruising and I mash the throttle,it’ll kick back to second and go,no worries. My issue is mashing the throttle from a standstill!
It’ll do a bit of wheel spin then bog a bit then take off. This is annoying as sometimes I want to take off with wheel spin and have some fun in the old girl. Same thing if trying to do a burnout! It’ll spin a bit then bog a bit then take off! I have accelerator pump on the top hole for the biggest squirt.
Any thoughts please.
I’ve read that I should upgrade to a double pumper if I want to do the occasional wheel spin/burnout.
Remember that edelbrock carbs have to reprime after sitting for a bit so first time you stab it after its been parked say overnight it will fall on its face .after that your fine.
Great information. No matter how hard I try I cannot get more than 14 pounds of mercury of vaccum from my Edelbrock carb. I have 350 small block with headers and mild cam on my C10. Already tune up. Any suggestions? My gas mileage stinks.
Take the carb off and make sure that the butterflies are closing all the way. There should only be a small square of the transfer slot still visible.
Check for any vacuum leaks. A big one that people miss is having a PVC line from a valve cover to the base of the carb or the intake, but then also installing a vent in the oil fill hole or other hole in the valve covers. If you are running a PCV hose, you Can Not Have atmospheric vents on the crankcase. The crankcase must be sealed at all other points. If you want to have the crankcase vented to the atmosphere, then you must plug the PCV ports.
Also, make sure that you are using the vacuum advance on the carburetor and have it plumbed to the manifold vacuum. Adequate timing advance at idle and part throttle is critical to pulling good vacuum and getting good fuel milage.
Just bought my 1st avs2. I've tuned many of the 1406 and 7s but this avs is now a learning process. A stock 350 vortec, high rise intake and hei dist, with headers. I'm experiencing a loss in vacuum for my brakes from the 1406 setup. Can adjusting the secondary valve improve this or not? Thanks alot.
Haven’t seen an instance with such an aggressive change between a carburetor change and power brakes. What was your vacuum numbers prior to the carburetor change and what are they now?
I had no idea how this thing worked, my truck would octane ping when the secondaries kicked in, it made no sense. the AVS was as loose as it could be, I tightened it and boom, problem gone, pulled just fine with no ping. the more I learn about these carbs the better I get it to run. thanks for the info
They aren’t overly difficult until to tune once you’ve got the knowledge and experience! Good work!
Quick question, Vacuum advance, driver side or passenger side of carb. 71 Chevy small block no emissions, I tried both sides and see no difference but what is correct ?
Mostly a stock engine or mild cam/intake/headers. Go with the timed port. Aggressive engine/cam then go with the full manifold vacuum until it can’t be used, then go with a locked out distributor and control with an aftermarket spark box.
Great info awesome video I have a little trouble adjusting the flap when running huge cam
For sure. It’s a limitation of that carb, but that’s why it’s geared more toward a street car. One area where the Holley will shine.
I've got the avs2 on a 305. When I floor it from cruising speed the secondarys don't open but if I release the throttle and floor it again then they will open. Would this help that problem if I made this adjustment?
Probably but it sounds like you might have other issues here. I’m assuming you went with a 500cfm for that engine. I’d just verify all the linkage operates freely. Make sure the secondary flap is operating freely. Next hit the accelerator pump and see if adding fuel or taking it away makes a difference. Then start playing with the opening rate and see if you can get improvements.
back fire so hard popped back of muffler out
I really like the way you work ! Excellent videos !
Question: Would the pump rod hole setting come into play with this hesitation problem ?
It can. It’s certainly worth checking. Kind of depends on throttle position, rpm, timing. But 100% yes, that’s a good thing to also try as you tune. Thank you!
Great video man ..... but do they make tools for these little clips cause my hands aren't made for tiny crap like that
Use a pick to remove them and you’re on your own on installing them! 😆
So I undid the lock screw without putting a screwdriver in the tension bolt and it “undid”. How many turns to get the bolt back to stock?
From all the way loose? Probably 3-4 full turns. Get it where you think it was and go drive it. You’ll know if it needs to go looser or tighter pretty quickly.
An Edelbrock tuned right is a sweet sweet deal I can get them to outrun some Hollies but with dead nuts reliability and consistency great torque production
They have their place in the market for sure. It just comes down to applying it correctly.
Again, you have done a great job !!
Could backfiring on hard deceleration be another issue related to poorly adjusted door?
It’s possible, but your challenge is to figure out if it’s a lean condition or a rich condition. Is it backfiring out of the exhaust?
So the older carburetors that don't have that adjustment are factory set at one rate of opening?
They have a weighted air valve. No adjustments.
Outstanding!! good info.👍
Thank you very much.
Great video,
Could you address the issue of how when you turn the car off after driving around sometimes the secondary fuel reservoirs (likened to the rear bowl on a holley) seem to empty and not refill to the point where if you accelerate hard and open the secondaries, there is no fuel there and the car will bog from fuel starvation.
I've heard the only way to prevent this from happening is to basically floor the motor BEFORE you get out on the road to make sure adequate fuel gets into the reservoirs in order to take Wide Open Throttle under load. It's actually a potentially very dangerous in a scenario where you pull onto a road when there is or could be a car coming up rapidly behind you
.
I believe Tony DeFeo (Uncle Tony's Garage) mentions this but doesn't go into why it happens and if there is any modification that can be done to make sure it won't happen unexpectedly.
thanks!
It’s heat soak. Put a spacer between the carb and intake to block the heat transfer. I did a full video on this topic.
@@MuscleCarSolutions I didn’t think it was because the motor only runs about 180 degrees but I can try a spacer. Thanks
I’ve been struggling with my avs2 and found your channel. You have brought reasoning into my chaotic efforts and slowed me down tremendously. However, When coming off the throttle my AFR gauge indicates full rich and sputters and runs rough until it gets cleaned out at higher RPMs. How do I get the carb to stop flooding the manifold at zero throttle? Secondly why do I get a lean condition with an automatic transmission upshift and constant throttle?
Thanks
Check out my fuel system video. Highly recommend a fuel pressure regulator. That video explains why. Set the floats. I have a video on how to set those. There is a dedicated playlist to Edelbrock carburetors. There are tons of videos in there that will help you get the basic settings for that carb. Step up springs is your next step and yeah I have a video for those too! Have to get the foundation set first, then you can start actually tuning. Glad you found the channel. Check that playlist out and don’t hesitate to ask questions along the way.
Fuel pressure is a little less than 6psi and I set the floats as you had suggested. Should I reduce that pressure some? I have silver springs in now and will try lighter.
Thanks a million
@@MuscleCarSolutions
You’re on the right path then. We still need to figure out why you’re in a flooding condition. If you’re comfortable that the pressure is at 6 and you’re still getting that condition then yes drop to 5psi. If it still is pushing fuel, then I’d verify the needle and seats are closing. No trash in them holding it open. No signs of debris in the fuel bowls. When we the last time you changed fuel filters? Lower the fuel level in the carb a little. If you set with the 7/16 drill bit method, then lower with a 1/2” and see if carrying less fuel helps.
Thank you for sharing this, very helpful! I turned the carburetor as best as I could and left this as default due to not getting the concept
It’s an easy adjustment but one that hasn’t been explained very well. Figured it was time to make a video about it. Glad you found it useful!
Hi I have a 318 mopar motor and I know it has more power but I’m not getting it. Do you have any advice on where to start. I had a efi on it and it did have more power I just can’t seem to achieve the same response and power from the carburetor
Don’t know. What tuning have you already done?
@@MuscleCarSolutions I just done what you explained in this video I have gotten better performance.
Good information
I'm new the these carbs. I have an non AVS I've picked up. Is there any adjustments on those? Do you have videos on the older ones? Not impressed with it as the secondaries open up. My old autolite 4100 seems to feel stronger on full throttle even though its a 480 CFM. I enjoy your videos. You are a carb guru!
The “feeling” isn’t measurable. If you’d really like to see if there is a point in the transition from the secondaries closed to opening, an AFR would confirm or reject your feelings. If you can tune to maintain a solid 12.5 AFR on that transition in WOT, then you know the carburetor is working as intended. The further benefit to the AFR is helping you get through the tuning process quicker with empirical data to help guide you though the steps. Yes, I have tons of videos on the performer series carburetors. I put them all into a playlist if you’d like to peek at it; th-cam.com/play/PLzRZhhuK5WiCO_FamS74Ci8hmQVbWsTpO.html
@@MuscleCarSolutions I'm not that familiar with the AFR set up. I do understand what it is and what it can tell me. I've just never been around one. All I've ever really tinkered with is the 4100. I bought a used Summit version of the 4100 for my Mustang ll and I like it alot. On my Fairlane (1964), I replace a 600 vac secondary Holley with this used Edelbrock 600 and the drivability is much better than the holley was. Still working through some issues on it. I have learned quite a bit from watching your videos on the Edelbrock. Thanks for your response and ideas on the AFR. I will look into that. Do you have any videos on the "Summit" carb?
@@f150bft you’re very welcome, and please don’t hesitate to ask any questions along the way. Always happy to help where I can.
I have not done any video on the summit brand carburetors but I have tuned one and wasn’t impressed at all. If I ever get my hands on one of my own, I’ll do a full review and tuning video to expose the weaknesses.
What’s your recommendation setting advance timing on a stock 350 rebuild once about 90,000 miles ago in a Chevy C10 three on the tree, oh and what should I set my rpm at idle? Thanks
Depends a bit on elevation as well, but generally I start at 12 and go up to 18 on initial. The engine will tell you what it likes (or doesn’t). Idle RPM is also going to be dictated by what the engine is asking for. If its still in decent shape and the valvetrain is still tight, you should get idle from 5-700 RPM. But it’s going to tell you what it wants. If you try 500 and it’s not enough when you let the clutch out to get moving, then add more.
@@MuscleCarSolutions ok right now I have set at 850-900 and I thought it was too high, I’m sitting at 500 elevation. And also my advance is set at 12 and it feels pretty good there. I’ll play with it a little more. Thank you so much for the info. Love your videos
@@chicanoperez6377 yup. Completely ok to play around with a little more timing to drop down the RPM. You’re working the process! I’m glad the videos have been useful to you!
Great video
Keep up the good work of your videos. Always look forward to your content
Very much appreciate that Jeff. Will be live from PRI this week. It’s going to be an amazing show!
Another great video! Keep up the good work.
Thanks Roy. Always appreciate you stopping by.
Quick question, and thanks for the video very informative, but when your making adjustments and trying to get rid of hesitation or bog, can you test this just in the driveway in park? Or do you have to drive it? Because I have a bog when I'm just sitting in park and mashing the throttle
You can’t check operation with no load on the engine. Sitting in the driveway = no load on the engine.
@@MuscleCarSolutions gotcha, thanks, just did some tinkering and took the car out, seems to be alittle bit better, still a slight hesitation but better then it was, might need a little bit more adjustment
@@stephendorsey4481 yup. Keep tuning.
Please get to the point.
Delivering information takes time. Very sorry it triggered you.
@@MuscleCarSolutions Triggered? Merely an observation, get over yourself.
@@chrishanley2372 and it triggered you again! Sheesh. I hope you’re feeling better soon.
Great vid! my car only in the morning when I start it if I don't hold the gas pedal a few second it will turn off but afterwards it runs great after it warms up. Are the secondaries something I can adjust so I don't have to hold pedal down few seconds at first start up?
Secondaries aren’t a factor with no load and low rpm. Adjusting then won’t have any affect in the issue. Can try the idle mixture screws first. Add more fuel and see if it gets better. If worse, take some away. Verify timing. Ensure no vacuum leaks. If it’s an electric choke carb then open the flap a little more. Gets better then go back to the mixture screws. Gets worse, take away some air. It’s where I’d start.
@@MuscleCarSolutions
Thanks, I made my electric choke a little richer and now it started right up in the morning.
Nice!
Man this was very helpful! Thanks!
Nice! Glad it was! Thank you.
How do u control when the secondaries kick In I believe mines kicking in way to early
Well the video does describe how to get them to engage quicker. The exact opposite will meter the fuel slower.
Maybe watch the video? 🫤
Informative as always, thank you!
Thank you!
Another great video!! Thanks again!!!
Thanks man! Happy holidays!
Interesting! I have an older 650 AVS in my pile of stuff...and I cannot make it work right. The drivers side mix screw acts normal, but the passenger side one has no effect, I can screw it all the way in and it makes no change. The car idles kind of strange. The exhaust sounds " Flat" if that makes sense...if I hit the throttle it will huff black smoke out the tailpipes. It was on a 383 Mopar when it was new, and he was never happy with it either.
In those situations I will always do a total reset. Turn the idle speed screw all the way out. Turn in and lightly seat the mixture screws and come back out a turn and half. Flip it over and verify the transfer slots aren’t exposed. Verify timing. Then start and set the speed screw, then mixture screws (with a vacuum gauge) and reset/check timing.
@@MuscleCarSolutions I'll dig it out and give that a try! Thanks!
@@harnettsgarage it’s common. I covered it in a video on how to set idle mixture screws. Especially engines with an aggressive cam. It’s easy to get into the transfer slots. Anything past 1000 rpm the idle circuit gets bypassed.
@@MuscleCarSolutions I went through my 1403 and set up the transfer slots, I can't remember if I did with this one...it was three summers ago now. I'll go watch the other video now!
Hi sir, love these videos. But, I've got a problem. I have a 318 in an 86' W-100. Brand new head-job, and Edelbrock on a Weiand manifold. Timed, about 8 BTDC, but back fires like MAD on any kind of load, uphill, and on any acceleration. At speed, coasting, down hill, warm and idling, no issues. All new ignition system, distributor, plugs leads etc. What am I doing wrong RE: adjustment? What could I be 'missing'?
The challenge here is to figure out if it’s an ignition related issue or a fuel delivery related issue. What size carburetor? Have you done any tuning yet?
Hi sir.@@MuscleCarSolutions It's the "Performer" series. I've done no tuning at all. No pressure regulator system, fuel delivery is right off the mechanical pump (there is an inline filter). New (rebuilt OEM) distributor (Reluctor type w/ vacuum and mechanical advance) with GM module conversion. All new plugs, leads, coil (internally resisted) battery and wiring. Starts fine, mechanical choke no issues. Idles fine. Gutless on hills, under load, under acceleration and backfires like a 50 Cal. M2. with any kind of pushing.
One strange thing, when timing, using a light, the mark even when set (8 Deg BTDC) would jump around a bit. So, the mark would flash in one spot for several seconds, then jump 1/2 degree for a second or two, and then back. Could be a number of things? Timing chain? Worn cam, lifters, push-rods? The truck only has 44k original miles on it, but was used hard, pulling trailers in the mountains.
@@erikg.4217 generally when the timing bounces around all over the place your assumption is correct. Timing set, distributor gear. Something is worn. You’re eventually (quickly) heading for a full rebuild or at the very least find where the issue is and hopefully be able to correct it. Time to start tuning. I’d add a regulator and a gauge at a minimum. Once you get the back firing sorted out, the tuning chart is your next step to fine tune. It might also circle back to your erratic timing. Might not be anything you can do until that’s sorted.
@@MuscleCarSolutions Thank you sir, my fears confirmed. No more driving until I locate the actual source of the issue. Might be dealing w/ several, but process of elimination will narrow it down some for sure. Thanks! E
Excelente explicación 👍
This is gold! I have been having hesitation on takeoff and on part to full throttle. Adjusting the accelerator pump linkage position fixed the former, but I've still been suffering from the latter. Once I'm back on the road hopefully this will fix me up!
Best of luck! Let me know if you have any questions when you get to working on it.
Thanks 🙏🙏
You’re welcome!
Great vid, I just put an avs2 on my truck. Seems to break up around 3500 cruising.
Cruising at 3500? Yikes. How is it geared? What trans?
@@MuscleCarSolutions th350 3.7.3
@@trilledskadesman3922 that would explain it. Do you have the right size carb? What is your fuel pressure set at? What tuning have you do so far?
@@MuscleCarSolutions the rear end would explain it?
@@MuscleCarSolutions mostly stock,msd ignition SBC 350 performer intake 650 cfm and headers
Can this cause the opposite issue back fire in the exhaust I have a stock 350 had no back fire with old carb. Put the avs2 on runs great. But rev it up in park and back fires in the exhaust when rpms drop back down
Could be a lean backfire. Timing would be a nice place to start. Not zinging it in park would be another good idea. Not necessary.
@@MuscleCarSolutions does it while driving also. I get it I was trying to adjust to make it go away
Truck was running fine with other carb swapped this one and the problem started
I have the older style edelbrock on to other vehicles. No problems like this. Brand new checked and adjusted like my others. Runs great like my other ones just back fires after high rpm on the way back down to low rpm
Timing set ect, holley stripped squitter screw so I popped this one on because the run well on my other chevys