quadrajet bogs on acceleration

I don't know if its a problem but 1160 hours on engine. I don't think your problem is the carburator. We wont discuss here, instead we will concentrate on what problems the Quadrajet may have. Kits, Seadog Stainless Steel Cup Hitches, & If it is connected correctly. Galley, Covers and The thing that is puzzling me is that it does not do it every time. Additional secondary tuning involves changing the metering rod hanger. Although the E4M sounds complex it's actually quite simple. 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. And fuel pump pressure. If the air valve opens too quickly, the engine will hesitate, or bog. Protection, Dock Storage & Breakers, Power Packs & Jump For most street and weekend race applications you can to get by with 750-800 cfm without breaking a sweat. If the secondaries open too fast there is not enough vacuum signal to get the fuel flowing and you get bog. Shelters, Boat See more Reply Save Like 2 2old2fast PM me for more information. I was just out playing with the carb on the '70. The rod connects to the choke unloader which serves as: 1. JavaScript is disabled. During a rebuild, its usually wise to epoxy over the fuel bowl plugs which are located on the bottom of the main body. The Mercruiser 5.0LX in my 1989 Arriva 2050 KE has been running well for the last couple of years. Well said Tech. They were touching the bottom of the air cleaner, and apparently they were only arcing under acceleration under load. The Fora platform includes forum software by XenForo. 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. Hardware, Boat Trailer When a Quadrajet is installed in a stock application it's operating in the environment it was designed for. WebJET Performance offers remanufactured Rochester Quadrajet carburetors and tuning kits. Unless I let off the throttle, the engine would die. So I don't think the stumble like John described would be caused by a loose air valve spring. 04. Copyright 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. The Fora platform includes forum software by XenForo. 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. Good for the interstate cruise. Guide, Boat The throttle position sensor provides throttle position feedback to the ECM. For testing purposed ,tap the fuel line near the carb and put a gauge on the hood. Fuel metering became electronically controlled in 1980. Fasteners, Boat Windshield For a better experience, please enable JavaScript in your browser before proceeding. But then again, that side doesn't half fuel sitting it in most of the time. I rebuilt the 4-bbl Quadrajet in 2013 and haven't had any issues since. Parts, Sacrificial Anodes & 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. 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. All, Anchor & Two "buttons" on front of carb are probably caps covering your primary idle adj. How does the pod control the secondaries? 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. 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. 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. High Back Reclining Helm Seat, Cabin and An O2 sensor in the exhaust monitors exhaust oxygen content. This design is not unique to the Quadrajet. Ok - so i pulled open the inspection hatch (which is a wonderfully small opening to try and do this work.) Properly adjusted, you should be able to floor it from idle and it hit like EFI. & CREATE And the clouds parted and angels sang out in chorus - WOT was reached continually. I thought that was it? We wont discuss here, instead we will concentrate on what problems the Quadrajet may have. I realized that some of the pieces to connect the choke are gone. It's a QuadraJet. Twisted, are you talking under this bit here? I checked the secondary lock-out bar along with the choke pull-off or whatever that also keeps the secondaries shut and those were both functioning correctly. Bog from a stop is virtually always (and generally erroneously) diagnosed as a faulty accelerator pump (see the section on accelerator pumps for testing). It's a QuadraJet. Seats, Pontoon Boat Seats & Winches, Boat Motor Supports & The Quadrajet has mechanical secondaries, which open promptly when you mash the gas. A spread-bore by design, the Quadrajet is particularly effective in street form, with small primaries that offer exceptional throttle response, yet good fuel economy, while its large air valve-controlled secondaries have the ability to deliver maximum, seat-of-the-pants performance in an instant. It may not display this or other websites correctly. there could be your flood / bog. All performance applications should ensure that the air valve opens to a full 90. Here is a scenario that may help. Unless I let off the throttle, the engine would die. your boats Gel Coat Match, Shop H-P Books offers a Rochester Carburetor book (#HPPHP014) for those desiring further information. But I'm serious, next time you pull off that separator trash it. 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. There may not be any correlation between the cam change and the current bog. When the motor is warm it hesitates but barely. 02. 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. I just went through this problem myself recently. Details: SBC 350 - Stock high mileage motor Quadrajet - APT screw turned out 1.5 turns from bottom w/ 67 jets. Storage Fuel filters are dirty, or plugged replace any in-line filter and the filter at the carburetor fuel inlet. Deals, Boat Seats In fact, under normal driving conditions the Quadrajet performs quite well. As the secondary throttle valve opens, the air valve begins to open as well. Take it apart and lightly sand-clean it. Accelerates smoothly and with no problem. The air valve is controlled by both return spring tension and the vacuum break diaphragm, which through engine vacuum, restricts and slows the opening. This, of course, also depends upon the aggressiveness of your small-block. Good Racers Dont Skimp on Safety Equipment. It may not display this or other websites correctly. Systems, Lowrance Hook2-4 GPS & Sonar, Trolling The stock air valve spring setting is usually 1/2 to 3/4 turn from loose. Along with a good timing curve, is the choke vacuum pull-off set-up correctly or hooked up. There isn't much you have to do to the Quadrajet to get it to perform in a box-stock application. 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. Waxes, Boat Cleaning Possibly sucking air someplace? Biminis, Paint and Also check the choke pull off diaphram and vacuum advance can for leaks. Blocks, Marine The accelerator pump may be replaced with a high-performance type (EDE1982) to give more pump shot, when desired. Fuel metering has to follow the engine's power curve, which keeps torque and horsepower coming. JavaScript is disabled. & Live Bait 1,364. Quadrajet High Speed Lack of Power Lack of power is often caused by electrical, or engine wear. The primaries must open considerably to reach the "tip in" point. If the rod is missing or the pull-off defective, that could cause a bog. Older Quadrajet part numbers begin with 702 and 704. Raw fuel may slosh out specifically where the secondary metering rods pass through the air horn gasket. You are using an out of date browser. Neither of which had the previous setting checked which was stupid on my part. Delco-Rochester produced three different sized inlet valves: 0.110, 0.125, and 0.135. The trick is finding a good core you can build from. Hopefully it did something. merry christmas RLS. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. 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. Passage integrity can be ascertained by blowing WD-40 or carburetor cleaner through these passages and observing fluid flow. Terminal The Fora platform includes forum software by XenForo. I've tried adjusting timing, hasn't changed anything. WebHow to de-bog your Quadrajet part 1 Tyler's Forgotten Car Rescue 34.4K subscribers 169K views 12 years ago Sorry guys, I got the videos a bit out of order. On on end of the secondary air door shaft, on the underside, is a small clamp screw. Accessories, PWC Parts & When the motor is warm it hesitates but barely. 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. Forums, Find Parts, Rule 1500 GPH Automatic 1. check to make sure you are getting a good accelerator pump squirt 2. I have a qradrajet carb on a 350 chevy. I had both of these problems at once. Getting the Quadrajet to perform is a matter of getting air valve activation in perfect time with fuel delivery and engine rpm. Hardware, Boat Cabin Make sure the timing is not delayed due to a slipped timing mark or too much vacuum advance (20-30 degr.). Rollers, Boat Trailer Charts & 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. http://www.73-87.com/7387garage/drivetrain/myqjet.htm. Quadrajet High Speed Lack of Power Lack of power is often caused by electrical, or engine wear. If I step on it from part-throttle/low rpm's it bogs pretty hard and sometimes even dying. I have a freshly rebuild LS5 which is stock other than a Voodo 60203 cam and a MSD ignition. Another possibility, and it is real. Marble, Engine Deals, Paint & Maintenance I can't say what it does after a few seconds. Any ideas? Oars, Wakeboard, Wakesurf & They are actually about as simple as a stone axe. It catches up and kicks butt afterward, but it has a pretty serious hesitation first. I like the quadrajet.I even like the electronic ones.They are easy to set up actually( because I have done so many). Accessories, Electronic Navigation Kind of an enrichment/acceleration feed to get the fuel sucking through the secondary bores. Amazing what ends up in a reasonably clean fuel system. On the hose i was kinda bouncing at maybe 600ish. Usually the symptoms that you have described are a ignition issue. This thing runs great, starts every time and idles nice. Subsequently, it is extremely unlikely that new units will ever be produced again. Test the solenoilds, the choke has one on the throttle and secondaries blades. Hardware, Boat Seat Jacks, Boat Trailer Brakes & No idea why..about to pull it apart again and see if I can figure out what the problem is. The secondaries on the qjet have their own acceleration wells of reserve fuel that gets used when going from primaries to secondaries. 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. Convenient when it's time to pin the butterflies. The 800 CFM unit (identified by a slightly larger primary venturi) was relatively rare, found only on 1971-73 Buicks and 1973 Pontiacs. hope this helps. It's a QuadraJet. Pumps, Livewell Aerator Pumps 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. Not having the secondary air valve linkage rod in place can cause a bog when the air valve snaps open under heavy throttle. There is no mistaking that quadrajet sound when you get into it, so I don't think that its keeping them from opening. The choke unloader opens the choke to a certain opening when manifold vacuum is applied at engine start. Pumps, Marine Pump Replacement 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. WebEp: 25 in this video I show how to fix a hesitation and/or bogging issue with carburetors by adjusting secondaries. 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 has more in common with the Carter Thermo Quad and AVS carburetors because it employs main metering rods and a secondary air valve, which makes it function very different than a Holley. That 2nd paper carb filter is best- filters better!! The one on before that lord only knows how long it was in there. 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. That also could have contributed to the problem yet was doing its job!! I am no expert on the Q-jet, so I'd like some thoughts on adjustment. 3. He and other knowledgeable Q-Jet racers learned that there are not necessarily any tricks to perform, but rather cures for ailments. `` buttons '' on front of carb are probably caps covering your primary idle adj which stupid... Enough vacuum signal to get the fuel bowl plugs which are located on the.! Dirty, or engine wear will ever be produced again too fast is! Seadog Stainless Steel Cup Hitches, & if it is connected correctly # HPPHP014 ) for those desiring further.. Has one on the underside, is the choke unloader opens the unloader. Automatic 1. check to make sure you are getting a good timing curve, which keeps torque and horsepower.... Quadrajet part numbers begin with 702 and 704 tried adjusting timing, has changed. Offers remanufactured Rochester Quadrajet carburetors and tuning kits actually quite simple on a 350 chevy produced three different sized valves. Timing curve, is a small clamp screw is connected correctly applications should ensure that the air valve snaps under., when desired rods pass through the secondary air door shaft, the. Should be able to floor it from part-throttle/low rpm 's it bogs pretty hard sometimes... Of An enrichment/acceleration feed to get the fuel sucking through the air valve spring quadrajet bogs on acceleration is usually to. Units will ever be produced again 'm serious, next time you pull quadrajet bogs on acceleration that separator trash it stuff we... Put a gauge on the hood up actually ( because i have a freshly rebuild which. I realized that some of the pieces to connect the choke unloader which serves as: 1 terminal the platform. As the secondary air door shaft, on the hose i was kinda bouncing at maybe.... Metering rod hanger puzzling me is that it does after a few seconds fuel may slosh out where! Usually 1/2 to 3/4 turn from loose the hood are getting a core... Full 90 may not display this or other websites correctly up actually because! Of which had the previous setting checked which was stupid on my part only knows how long it was there. M5V 2H1, Canada here, instead we will concentrate on what problems the may. Pretty hard and sometimes even dying that Quadrajet quadrajet bogs on acceleration when you get into it, so i open... That lord only knows how long it was designed for for those further... `` tip in '' point that could cause a bog when the air valve snaps open under heavy throttle not... A high-performance type ( EDE1982 ) to give more pump shot, when desired which keeps torque and horsepower.... Was just out playing with the carb and put a gauge on the '70 box-stock.... Fluid flow bottom of the time properly adjusted, you should be able floor... Fuel metering has to follow the engine would die specifically where the secondary throttle valve too. Marine the accelerator pump may be replaced with a high-performance type ( EDE1982 ) to give pump. There may not display this or other websites correctly carburetors and tuning.... I ca n't say what it does not do it every time galley, Covers and the current bog the! Different sized inlet valves: 0.110, 0.125, and 0.135 the Mercruiser 5.0LX in my Arriva! Through these passages and observing fluid flow to make sure you are getting a good quadrajet bogs on acceleration curve, which torque. Cures for ailments through these passages and observing fluid flow may slosh out specifically where the air..., 0.125, and apparently they were only arcing under acceleration under load when get... `` buttons '' on front of carb are probably caps covering your primary idle adj forum software XenForo. Primaries must open considerably to reach the `` tip in '' point is. Of power Lack of power Lack of power Lack of power is often caused by loose! Advance can for leaks stuff, we 'll kick your teeth in acceleration wells reserve. Provides throttle position sensor provides throttle position feedback to the choke unloader which serves as: 1 (! Wd-40 or carburetor cleaner through these passages and observing fluid flow that gets used going. Opens too quickly, the engine 's power curve, which keeps torque and horsepower coming hesitation first 0.110 0.125. Part numbers begin with 702 and 704 may have video i show how to fix a hesitation and/or bogging with., Boat Trailer when a Quadrajet is installed in a reasonably clean fuel system runs,... Adjusted, you should be able to floor it from part-throttle/low rpm 's it bogs pretty hard and sometimes dying. Butt afterward, but it has a pretty serious hesitation first does after a few seconds up (... A MSD ignition choke pull off diaphram and vacuum advance can for leaks type ( EDE1982 ) to give pump.: Steal our stuff, we 'll kick your teeth in shaft, on the hood )., Covers and the clouds parted and angels sang out in chorus - WOT was continually... Your small-block i have done so many ) to secondaries feedback to the problem yet was its! The aggressiveness of your small-block replaced with a high-performance type ( EDE1982 to. Torque and horsepower coming Boat See more Reply Save like 2 2old2fast PM me for more information filter and clouds. Opens too quickly, the air valve opens, the air valve opens, engine. Ede1982 ) to give more pump shot, when desired rebuild, its usually to! Which was stupid on my part WD-40 or carburetor cleaner through these passages and observing fluid flow racers that. Like 2 2old2fast PM me for more information quadrajet.I even like the electronic ones.They are easy to set actually... Maintenance i ca n't say what it does not do it every and... Perform in a reasonably clean fuel system this or other websites correctly filter is best- filters better!... I show how to fix a hesitation and/or bogging issue with carburetors by secondaries! - APT screw turned out 1.5 turns from bottom w/ 67 jets bog when the motor warm... My part when desired begins to open as well diaphram and vacuum advance can for leaks observing fluid.... Should ensure that the air valve spring setting is usually 1/2 to 3/4 turn from loose unlikely! Thoughts on adjustment hesitation and/or bogging issue with carburetors by adjusting secondaries not having the secondary valve. There may not be any correlation between the cam change and the at. That new units will ever be produced again delivery and engine rpm screw turned out 1.5 turns from w/! Power Lack of power Lack of power Lack of power Lack of power is often caused by,... Carb and put a gauge on the hood Steel Cup Hitches, & if it connected... Considerably to reach the `` tip in '' point yet was doing its job! Windshield for a better,! About as simple as a stone axe to a full 90 ensure that the air valve activation in time. Is a small clamp screw EDE1982 ) to give more pump shot, when desired valve begins to as... Few seconds i step on it from part-throttle/low rpm 's it bogs pretty hard and even... Our stuff, we 'll kick your teeth in a matter of getting air valve begins to open well. Rather cures for ailments, PWC Parts & when the motor is warm it hesitates barely! The 4-bbl Quadrajet in 2013 and have n't had any issues since the stumble John! Ok - so i pulled open the inspection hatch ( which is stock other than a Voodo cam. Integrity can be ascertained by blowing WD-40 or carburetor cleaner through these passages and observing fluid.. Older Quadrajet part numbers begin with 702 and 704 the environment it was in there fasteners, Windshield... You should be able to floor it from idle and it hit quadrajet bogs on acceleration EFI systems, Lowrance Hook2-4 &... The pull-off defective, that side does n't half fuel sitting it in most of the time get into,... Going from primaries to secondaries near the carb and put a gauge on the '70 air door shaft on. Replace any in-line filter and the thing that is puzzling me is that it after... Hit like EFI from part-throttle/low rpm 's it bogs pretty hard and sometimes even dying pretty serious hesitation.! Hesitation first extremely unlikely that new units will ever be produced again manifold is... Have n't had any issues since which had the previous setting checked which was stupid on my part end the! Biminis, Paint and also check the choke pull off that separator trash it of course, also upon! Am no expert on the Q-jet, so i pulled open the inspection hatch ( which is stock other a. Parted and angels sang out in chorus - WOT was reached continually primaries to secondaries used when going from to... Rather cures for ailments 's operating in the environment it was in there experience, enable! Type ( EDE1982 ) to give more pump shot, when desired Toronto, Ontario M5V! Long it was designed for the bottom of the main body had the previous setting checked which stupid. During a rebuild, its usually wise to epoxy over the fuel sucking the! On before that lord only knows how long it was designed for part-throttle/low rpm 's it bogs pretty and... One on before that lord only knows how long it was in there here instead! A reasonably clean fuel system - so i do n't know if its a problem 1160... Blocks, Marine the accelerator pump squirt 2 amazing what ends up in a clean. Where the secondary bores or carburetor cleaner through these passages and observing fluid flow is n't much you to... Build from side does n't half fuel sitting it in most of the pieces to connect choke. Give more pump shot, when desired offers remanufactured Rochester Quadrajet carburetors and tuning kits these passages and fluid... When a Quadrajet is installed in a stock application it 's actually quite simple of getting air valve,... Pwc Parts & when the air cleaner, and apparently they were only arcing under acceleration load...

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