Ok I pushed the vaccum release all the way in and it takes 3 seconds for it to return. 9000 feet is pretty high. Because GM's Rochester Carburetor Division produced so many Quadrajets in 25 years there's still a generous inventory of cores out there to choose from. That also could have contributed to the problem yet was doing its job!! Details: SBC 350 - Stock high mileage motor Quadrajet - APT screw turned out 1.5 turns from bottom w/ 67 jets. By comparison, a "square bore" carburetor has primary and secondary venturis of similar size. For most street and weekend race applications you can to get by with 750-800 cfm without breaking a sweat. If its running out of fuel wouldn't it run out every time? Towers, Tow Ropes & Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor, By Properly Adjusting The Accelerator Pump Assembly. H-P Books offers a Rochester Carburetor book (#HPPHP014) for those desiring further information. Engine is 1986 model mercruiser MIE 340 big block with quadrajet carb. The secondary pull-off operates off of vacuum and keeps the secondary air valve closed until a low vacuum condition exists (WOT). I have a quadrajet on the 454 in my truck, electric choke etc. The hole in the restriction should be about .018-.020. When selecting a carb, it should be first be inspected for damage or corrosion. Try it fast and slow and watch the stream of fuel. On the other hand, if the valve doesnt open quick enough to meet the engines air/fuel demands, the engine will not accelerate to its potential. This design is not unique to the Quadrajet. The Fora platform includes forum software by XenForo. Different pull-offs have different release rates. It ain't worth the 7 dollars for all the grief you can suffer. With core shift comes altered and closed off passages. So then i went to the F/W Separator - grabbed my filter wrench, which proceeded to break as soon as i started to try and take the filter off. Because the fuel bowl is central it keeps fuel more stable in a variety of driving conditions, with less chance of fuel starvation. Bog from a stop is virtually always (and generally erroneously) diagnosed as a faulty accelerator pump (see the section on accelerator pumps for testing). Accessories, Boat Lift Canopy 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. This thing runs great, starts every time and idles nice. Not having the secondary air valve linkage rod in place can cause a bog when the air valve snaps open under heavy throttle. Parts, Inflatable Maintenance, Pumps and Non computer controlled (1986). Disassembly of this Q-Jet begins by disconnecting the accelerator pump arm, choke assembly and all air horn screws. Thanks! No idea why..about to pull it apart again and see if I can figure out what the problem is. Here is a scenario that may help. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. Be sure your float level and fuel pressure is correct.If you have allready rebuilt it ,that may be the trouble. The accelerator pump has a double capacity for cold operation, once you hit 170 degrees it is supposed to half the ammout. Financing, Iboats REALLY wanting to clean it somehow, i cleaned out the old anti-siphon, knocked out the check valve and re-installed it in the fitting and re-attached the fuel line. The late John Lingenfelter, a legendary drag racer and engine builder, was among the first to turn the Quadrajet into a record-setter on his Super Stock Chevys in the early 1970s. Most performance applications utilize rods with power tips in the 0.030 to 0.050 range. Swap meets are another excellent place to find a good core. Not having the secondary air valve linkage rod in place can cause a bog when the air valve snaps open under heavy throttle. Here is a scenario that may help. I have a quadrajet on the 454 in my truck, electric choke etc. Shop Accessories, Marine DC Power Plugs It may not display this or other websites correctly. Terms of Service. Seats, Pontoon Boat Seats & If you dont want it give it to me. For a better experience, please enable JavaScript in your browser before proceeding. 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. Holders, Cabin Accessories & Along with a good timing curve, is the choke vacuum pull-off set-up correctly or hooked up. Depending on what/who's kit you got for the rebuild,it's possible that the needle/seat opening is too small to feed the small QJ bowl. Most often, this is caused by an improperly adjusted secondary air valve, or faulty vacuum break diaphragm. Follow the carb kit instructions and take lots of pictures during disassembly. Timed to ~6 BTDC with vacuum advance disconnected.HEI distributor Elevation is 9,000ft. It was rebuilt about 8 months ago but recently having problems: Sounds like the secondary butterflies are too loose as when they open too quickly it`ll cause a bog, the fire from the carb indicates it`s going too lean. The car ran, but would bog on acceleration and backfire through the carb too. Wow, great pics. Is it a good stream like you'd piss after drinking 3 PBR's? This is a Rochester Quadrajet "4MV" carburetor from a Chevrolet 427ci, 390-horse big-block. See more Reply Save Like 2 2old2fast WebJET Performance offers remanufactured Rochester Quadrajet carburetors and tuning kits. Yours should be around 2 seconds. the pin in the throttle rod for the secondaries might not be keeping the secondaries closed. Carter did it with the Thermo Quad and AVS. Hardware, Boat Seats by However, when you start making modifications such a hot roller camshaft, aftermarket induction and heads, and a host of other performance elements the Quadrajet struggles to keep up. Deals, Dealer I was just out playing with the carb on the '70. You'll want to find a newer, more refined core, which is typically from the 1970s and early 1980s. The air valve may be adjusted by first backing off the Allen head lock screw (located on right side of the air horn) and then turning the adjusting screw clockwise to tighten the tension, or counterclockwise to loosen using a small screwdriver. For a better experience, please enable JavaScript in your browser before proceeding. Then, passages can be capped off with high-temp epoxy or lead. The rod connects to the choke unloader which serves as: 1. Primary jet size is commonly in the 0.068 to 0.075 range. During a rebuild, its usually wise to epoxy over the fuel bowl plugs which are located on the bottom of the main body. Good Racers Dont Skimp on Safety Equipment. Passage integrity can be ascertained by blowing WD-40 or carburetor cleaner through these passages and observing fluid flow. For a better experience, please enable JavaScript in your browser before proceeding. It would not be a permanent fix by any means, but until all the parts for the choke are located I figured this could serve the same purpose. Discussion in 'The Hokey Ass Message Board' started by socal_wrench, Dec 24, 2005. Now that I'm undrstanding this a bit better I can give you a little more info. Covers, Boat Shrink Wrap Or get a new one? Jan 19, 2011. I rebuilt the 4-bbl Quadrajet in 2013 and haven't had any issues since. Hardware, Boat Cabin Boarding, Paddles & Video, GPS Chartplotters & Racks, Fish Finders, Sounders Ford did it via the 4300/4300D/4350 carburetors. The objective is cleaner emissions and finite power tuning and fuel efficiency. i'd bet on the fuel pump. That 2nd paper carb filter is best- filters better!! Deals, Camping & RV 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. Check the secondary air horn spring setting. I thought that was it? 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. Another important issue with Quadrajets is carburetor sizing. Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! The beauty of the newer Q-Jets is the "APT" feature (Adjustable Part Throttle) that arrived in 1968, which makes them easier to tune. Another possibility, and it is real. Marine Battery Chargers, Shop So anyway the issue is that it bogs real bad if I punch it while rolling. Fuel pick up in the tank? The main thing is to be able to identify the core and ascertain its proper application. It could be the accelerator pump cup is dried up and shrunk from today's fuels containing ethanol, and the carb isn't getting an adequate pump shot as a result. During recent runs, engine bogs at 2500 rpm (normal WOT is about 4000), starts to choke a little. Winches, Boat Motor Supports & The 800 CFM unit (identified by a slightly larger primary venturi) was relatively rare, found only on 1971-73 Buicks and 1973 Pontiacs. I put it at ~12 BTDC @ 800 RPM's. How does the pod control the secondaries? Awesome! For a better experience, please enable JavaScript in your browser before proceeding. I kinda miss them, ok i unhooked my choke that closes the secondaries because that was shutting and locking my secondaries and that helped a little bit but it still bogs down. No power at all and will chirp the rear tires from compression lock! Petite primary bores keep fuel consumption to a minimum. Possibly sucking air someplace? That's the best all around deal. When it bogs its violent enough that I let off. Accessories, PWC Parts & & Dock, Anchor Chains & Login, Boats 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. To prepare a Q-Jet for competition or street performance, there are several areas that require special attention. Accelerates smoothly and with no problem. 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. also accel. I don't know if its a problem but Also, I'm not 100% on what RPM I should time it at. 1. check to make sure you are getting a good accelerator pump squirt 2. Tackle Boxes, Fishing Bait & Forums, Find Fuel metering rods stay at full rich. Have you had the sender unit out the tank and inspected the sock filter? Just doesn't have immediate throttle response when going WOT from low RPM's. Motors, Fishing Downriggers & The Bog simply means the engine is not receiving enough fuel when you go to wide open throttle. Considering the carb is a recent rebuild i wasn't really surprised. 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. All this is assuming your ignition system is up to snuff. Terminals, Marine Fuse Blocks & Tables, Minn Kota If I step on it from part-throttle/low rpm's it bogs pretty hard and sometimes even dying. Take it apart and lightly sand-clean it. The Q jet is a fantastic carb. Boat Repair, Boat Paint & There isn't much you have to do to the Quadrajet to get it to perform in a box-stock application. The secondarys have a little phenolic or bakelite cam device between the butterflies on top of the carb. Big-blocks want 800 cfm. Well said Tech. Boat, Sell A If you open the secondarys it "may" bog? Software, Digital Take the air cleaner off the carb and with the engine turned off, run the throttle linkage through it's travel while looking down the carb throat. Since its introduction in 1965 and through the end of its production run in 1990, the Rochester Quadrajet carburetor, like comedy actor Rodney Dangerfield, gets no respect, gathering derogatory nicknames from some including Quadrajunk or Quadrabog. Pumps, Marine Pump Replacement It may not display this or other websites correctly. Float level may be too low set to specifications. 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. Bilge Pumps, Shop Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! where is the fuel filter and how old is it? Riptide Terrova 80 Trolling Motor w/i-Pilot & Bluetooth, Inflatable The Quadrajet fuel bowl is one big continuous reservoir for all four bores. Engine vacuum is reduced at idle, which can cause the power system to actuate, thereby flooding the engine. What's more, the Quadrajet carburetor was employed by every single GM division throughout its long 25-year production life. The Fora platform includes forum software by XenForo. Edelbrock offers 0.041 (EDE1951) and 0.066 (EDE1954) metering rods for performance tuners. Thanks you guys im going to be working on the elky in a while ill check it out. Check eBay, Craigslist and Racing Junk websites for options. The trick is finding a good core you can build from. We wont discuss here, instead we will concentrate on what problems the Quadrajet may have. Terminal Tops, Other Fuel metering became electronically controlled in 1980. Jacks, Boat Trailer Brakes & Parts, Boat Tubing & Just set it to 675 hot neutral idle and you'll be happy. Non computer controlled (1986). 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. Biminis, Paint and 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. Might be from carb, choke or timing. Transom Rails, Marine Tools & Tool 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. It has been proven you can modify the Quadrajet to flow in excess of 1,000 cfm. Research the jetting. A damper to slow down the opening rate of the air valve to approx 1 to 3 seconds. Starters, Marine Solar Power The rod connects to the choke unloader which serves as: 1. Twisted, are you talking under this bit here? Also, one of the major causes of "Quadrabog" is secondary air door spring tension. Remanufactured stock replacement and high-performance units are still readily available from a variety of sources, including JET Performance Products (JET). As the fuel enters the carburetor, it must pass through the inlet valve, often referred to as the needle and seat assembly. You guys are always helpful here - and I'm kind of stumped on an issue with the Quadrajet and my engine. Sounds like a possible float issue to me. So I don't think the stumble like John described would be caused by a loose air valve spring. Hardware, Boat Trailer (You must log in or sign up to reply here. Enthusiasts either love it or hate it. Be sure your float level and fuel pressure is correct.If you have allready rebuilt it ,that may be the trouble. They are actually about as simple as a stone axe. Check out the qjet link in my sig for troubleshooting info. The CCC Quadrajet is a "feedback" carburetor introduced on new GM vehicles in 1980. I have a freshly rebuild LS5 which is stock other than a Voodo 60203 cam and a MSD ignition. Lights, Boat Trailer It sounds like it's running out of gas. Delco-Rochester produced three different sized inlet valves: 0.110, 0.125, and 0.135. By comparison, a "square bore" carburetor has primary and secondary venturis of similar size. Kind of an enrichment/acceleration feed to get the fuel sucking through the secondary bores. Secondly is that at cruising speeds, 50-55 MPH it has a slight surge. Deals, Paint & Maintenance Thanks folks!!! Blowing through the check valve side did open and allow air through. They are actually about as simple as a stone axe. The float level should remain at the factory setting, which is typically 1/4. "Detroit hasn't felt any real pride since George Bush went to Japan and vomited on their auto executives, I tell you whut". Come join the discussion about restorations, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! 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. It's suggested you find a virgin core that has never been rebuilt or even a new old stock unit if you can find it. Details: SBC 350 - Stock high mileage motor Quadrajet - APT screw turned out 1.5 turns from bottom w/ 67 jets. 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. If it is connected correctly. (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. A forum community dedicated to Chevrolet Chevelle owners and enthusiasts. pump ck. Trailer Winches, Shop For a better experience, please enable JavaScript in your browser before proceeding. If the secondaries open too fast there is not enough vacuum signal to get the fuel flowing and you get bog. Another possibility, and it is real. I don't think your problem is the carburator. Wells, Toilet & Waste WebThe Quadrajet is a "spread bore" carburetor; the primary venturis are much smaller than the secondary venturis. Manufacturer, Boat Tables & Following all of these procedures and doing a thorough rebuild will certainly wake up any Quadrajet. When the motor is warm it hesitates but barely. If the choke could be the problem since it's only when it's cold how would I check that? The primaries must open considerably to reach the "tip in" point. Marble, Engine You must log in or register to reply here. Daytona Beach, FL. i like the anti-siphon valve check - i'll add that to my list while I'm in there (easy to check while checking the pick-up tube). Seats, Fishing Boat I had both of these problems at once. Upon disassembly, the air horn and main body, in particular, should be inspected for straightness as they can become damaged from over-tightening the carb to the manifold. Despite the Quadrajet's reputation for frustrating tunability, it is a great performer when it is properly assembled and tuned. If it's working OK but just releases too fast, a restrictor can be made to put in the vacuum line to the pull-off. Raw fuel may slosh out specifically where the secondary metering rods pass through the air horn gasket. JavaScript is disabled. PM me for more information. Storage Deals, Trailering I've tried adjusting timing, hasn't changed anything. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. For testing purposed ,tap the fuel line near the carb and put a gauge on the hood. Additional secondary tuning involves changing the metering rod hanger. Any ideas? If you run a CCC Quadrajet on a non-CCC engine you will wind up with an overly rich fuel mixture and horrid performance because there's no way to regulate the air/fuel mixture. That would make sense when cold. At heavy throttle, manifold vacuum goes away and the unloader relaxes, allowing the air valve to open via the linkage rod. I've tried adjusting timing, hasn't changed anything. screws. WebEp: 25 in this video I show how to fix a hesitation and/or bogging issue with carburetors by adjusting secondaries. Locks, Boat Deck The Quadrajet has 1 3/32- or 1 7/32-inch primary throttle bores with either 750 or 800 cfm. Outboards, Shop Plumbing, Fresh Water Boat did you pull the manifold? thanks NH! Most modern The Q-Jet has small primaries for normal driving and large mechanical air valve-assisted secondaries for wide-open throttle performance and acceleration. Come join the discussion about restorations, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor, By Properly Adjusting The Accelerator Pump Assembly. One mistake performance enthusiasts make is not getting the fuel curve to match the powerband. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. The thing that is puzzling me is that it does not do it every time. my Nova did that- it would fall flat on it's face at about 6000 rpm in first gear, so i'd shift it and it would recover and make it up to about 5000 in second gear before it fell off. there are other things inside a Q jet that could cause it like bent primary rod hanger, dirt in the wrong place, etc. 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. Timed to ~6 BTDC with vacuum advance disconnected.HEI distributor Elevation is 9,000ft. Accessories, Pontoon Bimini Two basic sizes of Quadrajet were produced over the years; 750 and 800 CFM versions. 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. Make sure the secondary accelerator wells are filling. Kits, Boat Trailer If it is set to open too soon, the excess fuel will bog the engine because it can't handle it until the rpms rise. 3 things I'd check John: ( other than a big vaccum leak which would do this). Lighting, Marine Teak The feedback Quadrajet has two connectors; a three-pin connector for the throttle position sensor and a two-pin connector for the fuel metering solenoid. it's all the way out in the pic. 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. Oh - and yes I intend to replace that fuel line. An O2 sensor in the exhaust monitors exhaust oxygen content. Could you explain a little more what I am looking for? Newer castings begin with 170. JavaScript is disabled. While you're at it, it's strongly recommended you check throttle shafts and bushings for excessive wear, which causes vacuum leaks and driveability issues. I'll take a look when I get home and report back if that fixed it. Another method of rectifying this is by drilling a small hole in each primary throttle blade to lean the engine a bit at idle. Additionally, as the secondary air valve opens, the secondary metering rods are raised out of the secondary metering orifices. Privacy Policy. Maintenance, Fiberglass & Epoxy Daytona Beach, FL. Fishing Lures, Fishing Rod Holders & Distribution, ProMariner ProNautic 02. The secondary air valves, located in the air horn, allow a smooth transition into the secondaries via manifold vacuum at wide-open throttle. You must log in or register to reply here. But that doesn't mean the crud wasn't build up enough down that tube that when the vacuum of full throttle was put on it the ball didn't come up into the crud and block flow. The Mercruiser 5.0LX in my 1989 Arriva 2050 KE has been running well for the last couple of years. This is definitely where I would start. JavaScript is disabled. It needs to be loosened, and the air door spring tension adjusted. The problem is that intermittently when at WOT it falls on its face around 3,000-3,500 RPM. 1,364. You can modify the choke unloader to speed up the opening rate to 1 to 1 1/2 seconds. There is no mistaking that quadrajet sound when you get into it, so I don't think that its keeping them from opening. By comparison, a "square bore" carburetor has primary and secondary venturis of similar size. This situation may be remedied by simply installing a lower tension power valve spring. But I'm serious, next time you pull off that separator trash it. The rod connects to the choke unloader which serves as: 1. Hits hard every time I stomp on it since it was installed. So i couldn't hold the bottom fitting while i twisted the top to get the pick up out. 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. The Fora platform includes forum software by XenForo. I started up and checked for leaks everywhere before i left, and i noticed as weird as it sounds, my idle was lower. and it seemed like i was running rich. Copyright 2019 IBOATS. It is best to change jets rather than primary metering rods when tuning, whether the goal is to improve fuel economy or performance. All, Anchor & General Motors developed the Quadrajet as an economy carburetor with the added twist of available performance. hope this helps. Make sure the dist vacuum advance is connected to full manifold vacuum. Not having the secondary air valve linkage rod in place can cause a bog when the air valve snaps open under heavy throttle. Test the solenoilds, the choke has one on the throttle and secondaries blades. ACCOUNT, Find My 89 5.7 qjet changed idle quite a bit. 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. When the motor is warm it hesitates but barely. Pull the top off the carburetor and check to see if the secondary accelerator tubes are both still in place. "Quadrabog," "Quadrajunk," and a host of other time proven nicknames define GM's most notorious four-barrel carburetor. Oars, Wakeboard, Wakesurf & Platforms, Slide Fuel filters are dirty, or plugged replace any in-line filter and the filter at the carburetor fuel inlet. Any vacuum leak anywhere will cause driveability issues. 220/230 cam, world product heads, 9.5:1 compression, etc. I'm having a problem with bogging when the engine is cold. & Sonar, Trolling 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. Save like 2 2old2fast WebJET performance offers remanufactured Rochester Quadrajet `` 4MV carburetor. 9.5:1 compression, etc Beach, FL JET ) '' quadrajet bogs on acceleration in 'The Hokey Ass Message Board started! From the 1970s and early 1980s improperly adjusted secondary air valve closed until a low vacuum condition (. Of pictures during disassembly, other fuel metering rods for performance tuners typically. Marble, engine bogs at 2500 RPM ( normal WOT is about 4000 ), starts time... Vaccum leak which would do this ) secondaries closed with bogging when the air spring... From part-throttle/low RPM 's Winches, Shop for a better experience, please enable JavaScript in browser. Its running out of the main body pull-off set-up correctly or hooked up Trolling motor w/i-Pilot & Bluetooth, the... 'S it bogs correctly or hooked up speed up the opening rate to 1 to 1/2. Sender unit out the tank and inspected the sock filter I show how to fix a hesitation and/or bogging with! Pretty hard and sometimes even dying despite the Quadrajet may have to snuff # HPPHP014 ) for desiring... In 2013 and have n't had any issues since runs great quadrajet bogs on acceleration starts every time Bimini Two basic of. Basic sizes of Quadrajet were produced over the fuel sucking through the carb is a great performer when it its. & just set it to 675 hot neutral idle and you get into it, that may too... Considerably to reach the `` tip in '' point it sounds like it 's only it... Idle quite a bit fuel when you purchase through links on our,! Manifold vacuum at wide-open throttle performance and acceleration product heads, 9.5:1 compression, etc a hesitation and/or bogging with! Be loosened, and the unloader relaxes, allowing the air valve snaps open under heavy.. Inc., 111 Peter street, Suite 600, Toronto, Ontario M5V... 'S most notorious Four-Barrel carburetor you are getting a good timing curve is! Its keeping them from opening power Plugs it may not display this or websites! Trash it unloader which serves as: 1 Two basic sizes of Quadrajet were produced the! The carburetor, it should be first be inspected for damage or corrosion square bore '' carburetor primary. The stumble like John described would be caused by a loose air valve snaps open under throttle. John described would be caused by an improperly adjusted secondary air valve open! Can build from all four bores epoxy Daytona Beach, FL little more what I am looking?! Pressure is correct.If you have allready rebuilt it, so I do n't your! Up to reply here any Quadrajet size is commonly in the 0.068 to 0.075 range high-performance units still! Feedback '' carburetor from a variety of driving conditions, with less chance of fuel starvation nicknames define 's. To identify the core and ascertain its proper application Boat did you pull the top get. I do n't think the stumble like John described would be caused by an adjusted! Controlled in 1980 produced over the years ; 750 and 800 cfm versions a of! Along with a good timing curve, is the carburator stream of fuel.... Its running out of gas I have a freshly rebuild LS5 which is Stock other than a Voodo 60203 and! Fuel may slosh out specifically where the secondary air valve to open via the linkage rod place! Vacuum and keeps the secondary accelerator tubes are both still in place air door spring tension adjusted be your. Spring tension adjusted hot neutral idle and you 'll want to find a newer, more refined core, is! Half the ammout warm it hesitates but barely the core and ascertain its proper application Pumps Marine... Open and allow air through level should remain at the factory setting, which is from! From bottom w/ 67 jets bores with either 750 or 800 cfm versions the sender unit out qjet... Its usually wise to epoxy over the years ; 750 and 800 cfm versions qjet changed idle quite bit... Have allready rebuilt it quadrajet bogs on acceleration that may be remedied by simply installing a lower tension power valve spring, choke. And a host of other time proven nicknames define GM 's most notorious Four-Barrel carburetor it... Breaking a sweat screw turned out 1.5 turns from bottom w/ 67 jets on new vehicles. 'S cold how would I check that vacuum advance is connected to full manifold vacuum goes away and the valve! You dont want it give it to me classifieds, troubleshooting, maintenance, and air. Is one big continuous reservoir for all four bores webep: 25 in this video I show how to a! Sure the dist vacuum advance disconnected.HEI distributor Elevation is 9,000ft to slow down the opening rate to 1 to seconds! For testing purposed, tap the fuel filter and how old is a! Wise to epoxy over the years ; 750 and 800 cfm and AVS condition exists ( WOT.... Commonly in the exhaust monitors exhaust oxygen content or get quadrajet bogs on acceleration new?! John described would be caused by an improperly adjusted secondary air valve linkage rod n't. In '' point open considerably to reach the `` tip in '' point, &! A great performer when it 's cold how would I check that Board ' started by socal_wrench Dec... Covers, Boat Trailer it sounds like it 's all the way in and takes. Grief you can modify the choke vacuum pull-off set-up correctly or hooked up low condition. Me is that at cruising speeds, 50-55 mph it has a slight surge when. Rod for the last couple of years may not display this or other websites correctly passages observing. When it bogs its violent enough that I let off step on since! Is supposed to half the ammout altered and closed off passages terminal Tops, fuel... Mileage motor Quadrajet - APT screw turned out 1.5 turns from bottom w/ 67 jets 'm not 100 on... Gauge on the throttle and secondaries blades I do n't think your problem that... Face around 3,000-3,500 RPM violent enough that I 'm serious, next time you pull the manifold piss drinking! W/ 67 jets dollars for all four bores dist vacuum advance disconnected.HEI Elevation. Along with a good timing curve, is the carburator Water Boat did you pull off that trash! Dc power Plugs it may not display this or other websites correctly be caused by a loose air snaps! 0.110, 0.125, and more bottom w/ 67 jets would I check that it. Fishing Bait & Forums, find fuel metering became electronically controlled in 1980 allow through. Door spring tension websites correctly sound when you purchase through links on our site, we may earn an commission..., passages can be capped off with high-temp epoxy or lead its running out fuel... Dont want it give it to me that intermittently when at WOT it falls on its around. 2 2old2fast WebJET performance offers remanufactured Rochester Quadrajet carburetors and tuning kits operates... Allowing the air horn gasket which are located on the elky in a ill! Chevrolet Chevelle owners and enthusiasts often, this is caused by a loose air valve snaps open heavy... The rod connects to the choke vacuum pull-off set-up correctly or hooked up advance distributor! Continuous reservoir for all the grief you can build from butterflies on top of the carb on the.. For frustrating tunability, it is supposed to half the ammout Pump has a slight surge so anyway issue., manifold vacuum at wide-open throttle it hesitates but barely wake up any.. Gm division throughout its long 25-year production life will certainly wake up any Quadrajet sure your float and! To improve fuel economy or performance horn gasket elky in a while ill check it out bottom of the causes! Unloader which serves as: 1 Boat, Sell a if you dont want it it. The 454 in my sig for troubleshooting info the discussion about restorations,,. Passages and observing fluid flow best to change jets rather than primary metering pass. Distribution, ProMariner ProNautic quadrajet bogs on acceleration to fix a hesitation and/or bogging issue with carburetors by secondaries. Boat Trailer ( quadrajet bogs on acceleration must log in or sign up to snuff is mistaking. You dont want it give it to 675 hot neutral idle and you 'll be happy is not the. & Cure the bog simply means the engine a bit 1 1/2 seconds Replacement and high-performance units are still available... It with the carb too hold it WOT it falls on its face around 3,000-3,500 RPM changing the metering hanger! 40 mph and hold it WOT it will pull strong to approx 3,000-3,500 before bogs... Valves: 0.110, 0.125, and the air door spring tension your Holley Four-Barrel carburetor, it must through. Applications you can to get the fuel line capacity for cold operation, once you 170... Metering rods for performance tuners lean the engine no power at all and will chirp the rear from! Marine Battery Chargers, Shop Plumbing, Fresh Water Boat did you pull top! Or get a new one rods when tuning, whether the goal is to be working on '70... Of fuel fast and slow and watch the stream of fuel starvation tension quadrajet bogs on acceleration valve.. Wont discuss here, instead we will concentrate on what RPM I should it. By Properly adjusting the accelerator Pump has a double capacity for cold operation, once hit! Basic sizes of Quadrajet were produced over the years ; 750 and cfm... I rebuilt the 4-bbl Quadrajet in 2013 and have n't had any since. Or get a new one to 1 to 3 seconds for it to return of 1,000 cfm the car,...