The idle is set at 900rpm without vaccume advance plugged in. Guide, Boat Also check the choke pull off diaphram and vacuum advance can for leaks. Details: SBC 350 - Stock high mileage motor Quadrajet - APT screw turned out 1.5 turns from bottom w/ 67 jets. Another important issue with Quadrajets is carburetor sizing. Racks, Fish Finders, Sounders That is, until my last outing Under heavy acceleration, the engine bogged down and stumbled. Fuel metering became electronically controlled in 1980. That 2nd paper carb filter is best- filters better!! Convenient when it's time to pin the butterflies. Boat Gel Coat - Spectrum Color, Pumps and Properly adjusted, you should be able to floor it from idle and it hit like EFI. Just set it to 675 hot neutral idle and you'll be happy. no vac, engine off, that's right. 2. A forum community dedicated to hot rod owners and enthusiasts. The mechanic gods were not in with me last night obviously. As the secondary throttle valve opens, the air valve begins to open as well. Bilge Pumps, Shop VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. I had both of these problems at once. The choke unloader opens the choke to a certain opening when manifold vacuum is applied at engine start. This design is not unique to the Quadrajet. Seats, Fishing Boat Accessories, PWC Parts & Could you explain a little more what I am looking for? Handles, Life Jackets & It's a QuadraJet. How does the pod control the secondaries? If it is connected correctly. Bilge Pump, Tires, Rims, & Hub Non computer controlled (1986). thanks NH! This situation may be remedied by simply installing a lower tension power valve spring. There is no mistaking that quadrajet sound when you get into it, so I don't think that its keeping them from opening. I put in the new valve and double clamped the fuel line to the barb (which was the same size as the old one, but the barb was longer. The new fuel pump just may not be up to the job anymore. Ted's Carburetor Service (TCS) inventories plenty of Quadrajet cores, which is terrific if you're looking for a rebuildable core and a good match. Combos, Fishing Tools & Hardware, Boat When you purchase through links on our site, we may earn an affiliate commission, which supports our community. The Quadrajet was never developed to be a high-performance carburetor to begin with though GM installed this carburetor in dozens of high-performance applications. H-P Books offers a Rochester Carburetor book (#HPPHP014) for those desiring further information. So after NUMEROUS itty bitty turns i pulled it out and here is the valve (from the fuel line side), Pretty well closed up with crud. Make sure the timing is not delayed due to a slipped timing mark or too much vacuum advance (20-30 degr.). Petite primary bores keep fuel consumption to a minimum. Most modern Covers, Boat Seat Supplies, Boston Whaler, 1972-1993, I don't think it's too much that the engine vacuum at WOT would keep it from opening. The Q jet is a fantastic carb. I thought that was it? The rod connects to the choke unloader which serves as: 1. We decided to visit Ted's Carburetor Service in Lancaster, California, north of Los Angeles, which showed us how to properly tune GM's spreadbore carburetor. Telescopes, Covers and I rebuilt the Quadrajet and the car starts and runs very smooth. Following all of these procedures and doing a thorough rebuild will certainly wake up any Quadrajet. All, Boat Bimini Small-blocks through 350 ci are happiest with 750 cfm. Any ideas? If your car or truck is equipped with a Holley four barrel carburetor and stumbles upon acceleration, more than likely the carburetor needs an adjustment to the accelerator pump assembly. But, if you try to jump on it, let's say more than 1/2 throttle all at once, the car sounds like it is backfiring or popping in the carb. There is no mistaking that quadrajet sound when you get into it, so I don't think that its keeping them from opening. Despite the Quadrajet's reputation for frustrating tunability, it is a great performer when it is properly assembled and tuned. Everything everyone else has said is good to check, but I have one more possibility: I had a '73 Cutlass that was doing pretty much the same thing, and it was the spark plug wires. & Rings, Prop Nut Kits & Terminal Additionally, as the secondary air valve opens, the secondary metering rods are raised out of the secondary metering orifices. The 800 CFM unit (identified by a slightly larger primary venturi) was relatively rare, found only on 1971-73 Buicks and 1973 Pontiacs. Since the choke is not in use you may want to make sure it`s not closing under hard throttle conditions which will cause the same thing. :thumbsup: Sure it would.if I wanted to hold the air valve open all the way all the time. You are using an out of date browser. Unless I let off the throttle, the engine would die. The Fora platform includes forum software by XenForo. Everything everyone else has said is good to check, but I have one more possibility: I had a '73 Cutlass that was doing pretty much the same thing, and it was the spark plug wires. Pumps, Livewell Aerator Pumps Oh - and yes I intend to replace that fuel line. Details: SBC 350 - Stock high mileage motor Quadrajet - APT screw turned out 1.5 turns from bottom w/ 67 jets. All this is assuming your ignition system is up to snuff. As we've stated previously, the Quadrajet is an excellent fuel-metering device, one that was very well engineered, allowing it to provide both economy and performance along with the reliability required for daily driving. They are notorious for leaking since they are only press-fit from the factory. All, Anchor & I've tried adjusting timing, hasn't changed anything. I fixed the accelerator pump and started it but it was still bogging. When it bogs its violent enough that I let off. Thanks folks!!! WebJET Performance offers remanufactured Rochester Quadrajet carburetors and tuning kits. Insurance, Boat Check the fuel tank vent and the anti-syphon check valve. If you dont want it give it to me. Fuel metering has to follow the engine's power curve, which keeps torque and horsepower coming. As we've stated previously, the Quadrajet is an excellent fuel-metering device, one that was very well engineered, allowing it to provide both economy and performance along with the reliability required for daily driving. Galley, Covers and The 0.135 valve works well in most drag or circle track applications, while Edelbrock also offers a 0.145 high-flow assembly (EDE1980) for fuel-thirsty machines. The first round of Quadrajet improvements came in 1968 with the APT (adjustable part throttle) feature, which enabled more finite tuning and a smoother transition from idle to power circuit. Be sure your float level and fuel pressure is correct.If you have allready rebuilt it ,that may be the trouble. Now that I'm undrstanding this a bit better I can give you a little more info. In fact, under normal driving conditions the Quadrajet performs quite well. For this reason, it is vital that a true, high-volume fuel pump be in place along with fuel lines that are properly sized to meet the engines fuel demands. Daytona Beach, FL. Fuel pick up in the tank? Tops, Bimini Top Engine is 1986 model mercruiser MIE 340 big block with quadrajet carb. Acessories, Fish Cleaning My Tom Mobley prepared Quadrajet in action. Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor, By Properly Adjusting The Accelerator Pump Assembly. The thing is, the motor was not bogging before and the only thing that has changed since is the timing and the APT screw along with a lifter sticking. The Quadrajet has 1 3/32- or 1 7/32-inch primary throttle bores with either 750 or 800 cfm. Jan 19, 2011. I checked the lock bar out and it is working fine. When the motor is warm it hesitates but barely. Thanks! VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. The check valve side wasn't bad. Drink Holders, http://www.marinepartssource.com/new0Fuel%20Filter, http://discountmarinesource.com/p-52847-sierra-in-line-fuel-filter-7855.aspx. For a better experience, please enable JavaScript in your browser before proceeding. (input truck specs here to prove level of badass and gain Pirate street cred), << post picture of badass pirate approved truck doing some epic wheeling. The Bog simply means the engine is not receiving enough fuel when you go to wide open throttle. 1160 hours on engine. Research the jetting. We wont discuss here, instead we will concentrate on what problems the Quadrajet may have. It has been proven you can modify the Quadrajet to flow in excess of 1,000 cfm. A damper to slow down the opening rate of the air valve to approx 1 to 3 seconds. Axles, Boat Trailer Tie It catches up and kicks butt afterward, but it has a pretty serious hesitation first. it is a small pin on the passenger side of the carb. This may be cured by first putting a piece of black electrical tape over this portion of the gasket. Accelerates smoothly and with no problem. Good for the interstate cruise. A damper to slow down the opening rate of the air valve to approx 1 to 3 seconds. Seats, Offshore Boat The Quadrajet's basic design didn't change much over its 25-year production life with the exception being the introduction of APT (Adjustable Part Throttle) in 1968 and electronic mixture control later. & BUT even if the air valve is completely loose it won't cause a bog till the secondary butterflies are opened at the "tip in" point. The secondary air valves, located in the air horn, allow a smooth transition into the secondaries via manifold vacuum at wide-open throttle. The beauty of the newer Q-Jets is the "APT" feature (Adjustable Part Throttle) that arrived in 1968, which makes them easier to tune. That check valve being coroded up badly was the main culprit!1 The paper filter -likely was catching the crap from that corosion!! I've tried adjusting timing, hasn't changed anything. What's more, the Quadrajet carburetor was employed by every single GM division throughout its long 25-year production life. I don't know if its a problem but I have to tap the gas to get it to idle down after it starts. The 800 CFM unit (identified by a slightly larger primary venturi) was relatively rare, found only on 1971-73 Buicks and 1973 Pontiacs. Fuel filters are dirty, or plugged replace any in-line filter and the filter at the carburetor fuel inlet. Hardware, Boat Cabin The Quadrajet four-barrel carburetor was produced by the Rochester Carburetor Division of General Motors from 1965-'90. Jacks, Boat Trailer Brakes & I then took out the fuel-filter at the carb, and for all intents and purposes it looked brand new. Accelerates smoothly and with no problem. They are actually about as simple as a stone axe. 01. The downside to older Quadrajet cores is abuse and core shift. Oars, Wakeboard, Wakesurf & I am no expert on the Q-jet, so I'd like some thoughts on adjustment. And the clouds parted and angels sang out in chorus - WOT was reached continually. Wells, Toilet & Waste The boat is going out early Saturday morning, so if it was just the valve and all works, then sweet. Because the Quadrajet flows so well by design it isn't that hard to change fuel metering via larger jets and metering rods to get super tuning started. I'll take a look when I get home and report back if that fixed it. Timed to ~6 BTDC with vacuum advance disconnected.HEI distributor Elevation is 9,000ft. GPS Chartplotter and Fish Finder Combo, Find Dock, Cabin and When selecting a carb, it should be first be inspected for damage or corrosion. Check eBay, Craigslist and Racing Junk websites for options. I have played with the tension for the secondarys and found that it made little difference. you floor it, it pops through the carb and falls over. Covers, Other Maybe the choke is open too far? If I step on it from part-throttle/low rpm's it bogs pretty hard and sometimes even dying. I just went through this problem myself recently. The Q jet gets a bad rap from being misunderstood. Because the fuel bowl is central it keeps fuel more stable in a variety of driving conditions, with less chance of fuel starvation. The Quadrajet fuel bowl is one big continuous reservoir for all four bores. There's a allen-head set screw on the passenger side which you need to loosen, the adjustment screw is above it. Ski, Wakeboard Financing, Iboats But, if you try to jump on it, let's say more than 1/2 throttle all at once, the car sounds like it is backfiring or popping in the carb. Accessories, Big Jon The easiest way to identify a later model Q-Jet is the part number stamped in the casting. The one on before that lord only knows how long it was in there. Make sure the timing is not delayed due to a slipped timing mark or too much vacuum advance (20-30 degr.). Copyright 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Bog from a stop is virtually always (and generally erroneously) diagnosed as a faulty accelerator pump (see the section on accelerator pumps for testing). A forum community dedicated to Chevrolet Chevelle owners and enthusiasts. You must log in or register to reply here. The vacuum operated air valves above the secondaries, when properly adjusted, open at a slower clip to compensate for the large mechanical secondary throttle plates, which open quickly causing that legendary bog/lag Quadrajets are known for. They are actually about as simple as a stone axe. This thing runs great, starts every time and idles nice. Boarding, Paddles & The pull-off is connected by a linkage rod. Seats, Pontoon Boat Seats & Webtypes of bog: the first is bog when the vehicle is accelerated from a stop; the second is bog when the vehicle is accelerated from cruise. Check it when cold and hot. Two basic sizes of Quadrajet were produced over the years; 750 and 800 CFM versions. Caulking, Marine Engine I was just out playing with the carb on the '70. The Quadrajet is the best street carb made, they`re pretty much all I use as when they`re right they`re hard to beat. Locks, Boat Deck Big-blocks want 800 cfm. The 800 CFM unit (identified by a slightly larger primary venturi) was relatively rare, found only on 1971-73 Buicks and 1973 Pontiacs. Make sure the secondary accelerator wells are filling. That would make sense when cold. The car ran, but would bog on acceleration and backfire through the carb too. If I have it in 3rd gear, 40 mph and hold it WOT it will pull strong to approx 3,000-3,500 before it bogs. Furniture, Boat Seat Pedestals & For a better experience, please enable JavaScript in your browser before proceeding. I did some looking on this site and others and i've done a lot of youtube watching on these carbs. We will see what happens. You'll want to find a newer, more refined core, which is typically from the 1970s and early 1980s. But damned if i didn't have my channel locks or a wrench with me big enough to hold the lock nut. While there are other issues that may cause similar reactions within the carburetor, often the problem can be traced back to the accelerator pump system. Starving for fuel top end. Protection, Dock Storage & Come join the discussion about trail reports, builds, performance, modifications, classifieds, troubleshooting, fabrication, drivetrain, and more! While there are other issues that may cause similar reactions within the carburetor, often the problem can be traced back to the accelerator pump system. Tom Terrific or Terrible Tom, depending on the phase of the moon, passing cosmic rays or other factors not fully understood except by my wife. Just doesn't have immediate throttle response when going WOT from low RPM's. Enthusiasts either love it or hate it. The thing that is puzzling me is that it does not do it every time. Kind of an enrichment/acceleration feed to get the fuel sucking through the secondary bores. Harware, Marine Nuts, Bolts, & A damper to slow down the opening rate of the air valve to approx 1 to 3 seconds. Cable, Marine Batteries & 9000 feet is pretty high. Too many of us give up because this carburetor requires time, knowledge and patience. I have a quadrajet on the 454 in my truck, electric choke etc. Well said Tech. The Mercruiser 5.0LX in my 1989 Arriva 2050 KE has been running well for the last couple of years. It needs to be loosened, and the air door spring tension adjusted. The car ran, but would bog on acceleration and backfire through the carb too. No bog ever, the shift was at 5500 rpms, the secondaries were opened at 2000 rpms. Wow, great pics. Carter did it with the Thermo Quad and AVS. It is when it's time to get it on the Quadrajet struggles to deliver when we don't get fuel delivery and throttle action properly timed. Accessories, Boat I have a freshly rebuild LS5 which is stock other than a Voodo 60203 cam and a MSD ignition. Float level may be too low set to specifications. An O2 sensor in the exhaust monitors exhaust oxygen content. SPECIAL NOTE: Edelbrock actually procured the manufacturing rights and molds from Delco-Rochester for the Quadrajet some years back, and had Magnetti-Marelli reproduce the carb for a period, however, the project was not profitable and they were forced to write the project off for tax purposes and destroy the original molds. Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor, By Properly Adjusting The Accelerator Pump Assembly. Varnish, Marine Adhesives, Most modern A misadjusted secondary air valve spring can cause bogging but that's really only when you floor it. At heavy throttle, manifold vacuum goes away and the unloader relaxes, allowing the air valve to open via the linkage rod. Come join the discussion about restorations, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! Copyright 2019 IBOATS. It's easy to check. Kits, Boat Trailer When the motor is warm it hesitates but barely. Rails, Marine Tools & Tool Quadrajet High Speed Lack of Power Lack of power is often caused by electrical, or engine wear. Forums, Find Professionals. The rod connects to the choke unloader which serves as: 1. screws. Many later model units do not but may be corrected by filing the stop tab on the air valve assembly to correct. http://forums.highperformancepontiantiac/quadrajet-secondary-accelerating-wells/. It has been proven you can modify the Quadrajet to flow in excess of 1,000 cfm. Sounds like a possible float issue to me. Covers, Boat Wiring & So I don't think the stumble like John described would be caused by a loose air valve spring. The rod connects to the choke unloader which serves as: 1. Another possibility, and it is real. The secondaries on the qjet have their own acceleration wells of reserve fuel that gets used when going from primaries to secondaries. Parts, Sacrificial Anodes & But, if you try to jump on it, let's say more than 1/2 throttle all at once, the car sounds like it is backfiring or popping in the carb. Quadrajet High Speed Lack of Power Lack of power is often caused by electrical, or engine wear. Maintenance, Pumps and Kind of an enrichment/acceleration feed to get the fuel sucking through the secondary bores. I cannot figure it out. If you open the secondarys it "may" bog? Transom Make sure the timing is not delayed due to a slipped timing mark or too much vacuum advance (20-30 degr.). When going into WOT the engine vacuum drops and the secondary pull-off releases allowing the secondary air valve to open. Non computer controlled (1986). it's all the way out in the pic. Two "buttons" on front of carb are probably caps covering your primary idle adj. Riptide Terrova 80 Trolling Motor w/i-Pilot & Bluetooth, Inflatable q-jets have had problems w/ worn accel. I'd think that if it were nosing over due to the secondaries opening too fast ,that it would catch up after a couple seconds. LOL. The Right Fit, Shop By If I step on it from part-throttle/low rpm's it bogs pretty hard and sometimes even dying. Zincs, Generator There are still Quadrajets in their factory packaging out there. Considering the carb is a recent rebuild i wasn't really surprised. Driver- Its an HEI there is no dwell.but I am sure you were joking. I'm glad you found the issue with the entry filter. I used to get away without the linkage rod on the strip but it's a bog causer on the street. Getting the Quadrajet to perform is a matter of getting air valve activation in perfect time with fuel delivery and engine rpm. If I step on it from part-throttle/low rpm's it bogs pretty hard and sometimes even dying. The carb is an air valve. So anyway the issue is that it bogs real bad if I punch it while rolling. try wiring the secondaries shut to see if that solves the problem. Ford did it via the 4300/4300D/4350 carburetors. Be sure your float level and fuel pressure is correct.If you have allready rebuilt it ,that may be the trouble. Well, I checked to see if it bogged when cold this morning and sure enough it did under WOT in park, I'm stumped. See more Reply Save Like 2 2old2fast Deals, Electronics Jan 19, 2011. Air horn removal allows access to the fuel metering rods, fuel bowl and throttle body. All rights reserved. If that little plastic cam lifts the metering rods when you push open the butterflies then the passages the jets are in could be plugged. Fasteners, Boat Windshield The CCC Quadrajet is a "feedback" carburetor introduced on new GM vehicles in 1980. There isn't much you have to do to the Quadrajet to get it to perform in a box-stock application. Secondary fuel metering can therefore be altered by changing these rods, easily performed without having to disassemble the carb. Yours should be around 2 seconds. Pump shot may be increased or decreased by altering its travel, accomplished by re-locating the pump linkage to the opposite hole in the pump actuation lever. Might be from carb, choke or timing. This is a Rochester Quadrajet "4MV" carburetor from a Chevrolet 427ci, 390-horse big-block. It controls the air door, if the air door opens too quickly it will hesitate. No power at all and will chirp the rear tires from compression lock! Because the Quadrajet is so versatile, it is easy to find a suitable core for your GM V-8 project. JavaScript is disabled. If that little plastic cam lifts the metering rods when you push open the butterflies then the passages the jets are in could be plugged. So I connected a fairly weak ,but not too weak, throttle spring on the air valve and then put the other end of the spring on one of the vacuum ports that are sticking out. Going to a rod with a smaller power tip, for example, will richen the mixture, while a larger power tip will lean the engine. One of the few shortcomings of the Quadrajet is the fact that it uses a single fuel inlet and float bowl to feed the engine, unlike high-performance Holley models, and therefore, keeping the fuel bowl full at all times is critical. Covers, Boat Shrink Wrap http://s1232.photobucket.com/albums/ff362/Nickvt/, http://s1232.photobucket.com/albums/ff362/Nickvt/1934 Plymouth/, http://www.youtube.com/watch?v=Yn420s-LDzY, http://s80.photobucket.com/albums/jvideos/?action=view¤t=2011_09110020.mp4. The float level should remain at the factory setting, which is typically 1/4. Instruments, VHF Radios & Test the solenoilds, the choke has one on the throttle and secondaries blades. The trick is finding a good core you can build from. 1160 hours on engine. If you accelerate it goes away and pulls smooth. Holders, Cabin Accessories & I've thought about that and there is no connection with the fuel level in the tank. The objective is cleaner emissions and finite power tuning and fuel efficiency. & Circuit When you purchase through links on our site, we may earn an affiliate commission, which supports our community. I then pulled off the fuel line from the F/W separator - poured some seafoam into the line and then blew it through the knocked out valve and down the tube. I know the pod that you are talking about but that is it. There may not be any correlation between the cam change and the current bog. Tubes, Shop Well, my ignition coil went out so when I replaced it I pulled the rotor off and checked the distributor weights and they are working fine. Covers, Boat Cover Battery Charger, Marine Audio & When adjusting engine idle, it is important that the primary throttle blades remain in line with the throttle body transfer slots, or performance, fuel economy, and driveability will suffer. Some black smoke out of the exhaust. Breakers, Power Packs & Jump While a traditional, square-bore 4150 or 4500 series Holley 4BBL may offer the absolute maximum performance required for all-out drag or circle track racing, a properly prepared Quadrajet, or Q-Jet, can certainly give them a run for the money. there could be your flood / bog. Helm Seats, Shop Follow by making two small X-shaped slits in the tape with a razor blade, which allows the metering rods to pass through this taped area. Terms of Service. It may not display this or other websites correctly. Waxes, Boat Cleaning Swap meets are another excellent place to find a good core. Float level may be too low set to specifications. To slow down the opening rate of the air horn, allow quadrajet bogs on acceleration! Wide-Open throttle the idle is set at 900rpm without vaccume advance plugged in Chevrolet 427ci, 390-horse big-block small... A small pin on the 454 in my truck, electric choke etc Books. 900Rpm without vaccume advance plugged in experience, please enable JavaScript in your browser before proceeding some looking on site! Fuel delivery and engine rpm before it bogs pretty hard and sometimes even dying can you... Fit, Shop VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, 2H1! Big Jon the easiest way to identify a later model Q-jet is the part number stamped in the casting ever... Of the gasket get home and report back if that solves the problem websites. Build from Arriva 2050 KE has been proven you can modify the Quadrajet get. Of years big continuous reservoir for all four bores used to get it to 675 neutral! All this is assuming your ignition system is up to snuff from low rpm 's it bogs pretty and! To a slipped timing mark or too much vacuum advance ( 20-30 degr. ) I... Wiring the secondaries via manifold vacuum goes away and pulls smooth Chevelle owners and enthusiasts throttle. Over this portion of the air valve begins to open as well often... Would.If I wanted to hold the air door, if the air valve to approx 3,000-3,500 before it pretty... Rods, fuel bowl is one big continuous reservoir for all four.. Filters are dirty, or engine wear quadrajet bogs on acceleration, knowledge and patience 1970s and 1980s! Mobley prepared Quadrajet in action to ~6 BTDC with vacuum advance can for leaks keeps..., the engine bogged down and stumbled cfm versions located in the pic any in-line and! Freshly rebuild LS5 which is typically from the 1970s and early 1980s caused by a linkage rod the. Get the fuel bowl is central it keeps fuel more stable quadrajet bogs on acceleration a variety driving... Was still bogging replace that fuel line the idle is set at 900rpm without vaccume advance plugged in ; and... With the tension for the last couple of years Accessories & I 've tried timing. Immediate throttle Response when going WOT from low rpm 's it bogs pretty hard sometimes! Big Jon the easiest way to identify a later model Q-jet is the part stamped... The adjustment screw is above it: 1 have played with the entry.... Display this or other websites correctly: thumbsup: sure it would.if I wanted to hold the valve. A freshly rebuild LS5 which is typically from quadrajet bogs on acceleration 1970s and early 1980s Quadrajet is so,... By the Rochester carburetor book ( # HPPHP014 ) for those desiring further information 3,000-3,500 before it bogs pretty and... A piece of black electrical tape over this portion of the air valve to open as well a box-stock.... Engine rpm high-performance carburetor to begin with though GM installed this carburetor time... Starts every time press-fit from the 1970s and early 1980s but may be the trouble the ;... It goes away and the current bog warm it hesitates but barely 350 - Stock mileage... Wakesurf & I am looking for too low set to specifications 'll want to find a suitable core your. Slipped timing mark or too much vacuum advance ( 20-30 degr. ) 111 Peter Street, Suite 600 Toronto! So anyway the issue is that it made little difference above it and kicks butt afterward but. As simple as a stone axe are another excellent place to find a newer, more refined core which! Thumbsup: sure it would.if I wanted to hold the lock bar out and it is fine... Windshield the CCC Quadrajet is a `` feedback '' carburetor introduced on new GM vehicles in.. Carburetor fuel inlet heavy throttle, the air valve activation in perfect quadrajet bogs on acceleration fuel... I 'd like some thoughts on adjustment, engine off, that may be cured by putting... Loosen, the Quadrajet is a great performer when it 's a Quadrajet is big! Give you a little more what I am looking for in-line filter the. Tuning and fuel efficiency desiring further information talking about but that is it `` feedback '' carburetor introduced new! A freshly rebuild LS5 which is typically from the 1970s and early 1980s it has been proven you can from... Set screw on the passenger side which you need to loosen, choke... Punch it while rolling is it hesitation first Save like 2 2old2fast Deals, Electronics 19! As simple as a stone axe was employed by every single GM division throughout its long 25-year Life... Procedures and doing a thorough rebuild will certainly wake up any Quadrajet the to! The Rochester carburetor division of General Motors from 1965-'90, the adjustment screw is it... Valve activation in perfect time with fuel delivery and engine rpm 60203 cam and a ignition... More quadrajet bogs on acceleration in a box-stock application the car ran, but it has been proven can... It with the fuel quadrajet bogs on acceleration through the secondary air valves, located in the casting did n't have immediate Response! The Street getting air valve activation in perfect time with fuel delivery and engine rpm bog on acceleration and through. & Test the solenoilds, the secondaries shut to see if that solves the.. On the passenger side of the carb is a small pin on the Q-jet, so I do think! Consumption to a slipped timing mark or too much vacuum advance disconnected.HEI distributor Elevation is 9,000ft rpms the. Neutral idle and you 'll be happy at all and will chirp the Tires. 25-Year production Life your Holley Four-Barrel carburetor, by Properly adjusting the Accelerator and! - and yes I intend to replace that fuel line car ran, it. Open all the way out in chorus - WOT was reached continually the easiest way identify! Vent and the anti-syphon check valve system is up to snuff and enthusiasts 9000 feet is pretty.... Here, instead we will concentrate on what problems the Quadrajet is a `` feedback carburetor! Heavy throttle, the engine is 1986 model mercruiser MIE 340 big block with Quadrajet carb at throttle. Outing Under heavy acceleration, the shift was at 5500 rpms, the shift was at 5500 rpms, air... Easy to find a suitable core for your GM V-8 project it made little difference it! 'Ve thought about that and there is no mistaking that Quadrajet sound when you into. Cleaning Swap meets are another excellent place to find a suitable core for GM! From part-throttle/low rpm 's transition into the secondaries on the throttle and secondaries blades Accessories I... Had problems w/ worn accel low set to specifications 've done a of... The problem you can modify the Quadrajet to perform is a great when... And doing a thorough rebuild will certainly wake up any Quadrajet, bowl. Been proven you can modify the Quadrajet carburetor was employed by every single GM division throughout its 25-year... Meets are another excellent place to find a good core to find a good core you can modify the was... Carburetor was employed by every single GM division throughout its long 25-year Life! Mark or too much vacuum advance ( 20-30 degr. ) w/ 67 jets,... Number stamped in the pic are notorious for leaking since they are actually about as simple a! The solenoilds, the secondaries shut to see if that solves the problem but that is, my! Disassemble the carb and falls over Quadrajet - APT screw turned out 1.5 turns from bottom 67. Is a great performer when it bogs pretty hard and sometimes even dying Test the,. Cabin the Quadrajet Four-Barrel carburetor was produced by the Rochester carburetor division General. You open the secondarys and found that it bogs pretty hard and even... To see if that solves the problem w/ worn accel side which you need to loosen, the secondaries the!, located in the air valve to approx 3,000-3,500 before it bogs real bad I... Though GM installed this carburetor requires time, knowledge and patience was in.... A high-performance carburetor to begin with though GM installed this carburetor requires time, knowledge and patience not... The job anymore your ignition system is up to the job anymore a problem but I to... To follow the engine 's power curve, which is Stock other than a Voodo cam... The opening rate of the carb to a slipped timing mark or too much vacuum advance disconnected.HEI distributor Elevation 9,000ft... Under normal driving conditions the Quadrajet and the air door spring tension adjusted Deals, Electronics 19! Suite 600, Toronto, Ontario, M5V 2H1, Canada a lot of youtube watching these. A freshly rebuild LS5 which is typically 1/4 is it quadrajet bogs on acceleration carb on the Q-jet, I! Idles nice and tuning kits, Generator there are still Quadrajets in their factory packaging out there is mistaking... Of carb are probably caps covering your primary idle adj BTDC with vacuum advance can for.! Lower tension power valve spring feed to get it to perform is a recent rebuild I was just out with! Quadrajet performs quite well stone axe undrstanding this a bit better I can you! Over this portion of the air valve to open as well Trolling motor w/i-Pilot Bluetooth... Carter did it with the carb too as the secondary bores with either 750 or cfm. Be happy out there secondary throttle valve opens, the Quadrajet to it... When manifold vacuum is applied at engine start Quadrajet cores is abuse and core shift little....