Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor, By Properly Adjusting The Accelerator Pump Assembly. Hitches, & For a better experience, please enable JavaScript in your browser before proceeding. Might be from carb, choke or timing. Amazing what ends up in a reasonably clean fuel system. Varnish, Marine Adhesives, There is no mistaking that quadrajet sound when you get into it, so I don't think that its keeping them from opening. A Quadrajet rebuild is actually quite simple. Petite primary bores keep fuel consumption to a minimum. Tables, Minn Kota When going into WOT the engine vacuum drops and the secondary pull-off releases allowing the secondary air valve to open. I had both of these problems at once. 01. WebThe Quadrajet is a "spread bore" carburetor; the primary venturis are much smaller than the secondary venturis. This added to my concern for the pick up tube. also accel. So i couldn't hold the bottom fitting while i twisted the top to get the pick up out. 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. 1160 hours on engine. Vacuum leaks can exist away from the engine, such as at the power brake booster, climate control, and more. I vote for a worn accelerator pump in the carb. 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. Marine Battery Chargers, Shop Despite the Quadrajet's reputation for frustrating tunability, it is a great performer when it is properly assembled and tuned. Shelters, Boat 05. Few realize that the Q-Jet has a strong racing heritage, particularly in NHRA Stock and Super Stock drag racing where an OEM carburetor is required. The Quadrajet has 1 3/32- or 1 7/32-inch primary throttle bores with either 750 or 800 cfm. your boats Gel Coat Match, Shop VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. Jan 19, 2011. Most often, this is caused by an improperly adjusted secondary air valve, or faulty vacuum break diaphragm. A forum community dedicated to Chevrolet Chevelle owners and enthusiasts. Follow the carb kit instructions and take lots of pictures during disassembly. But I'm serious, next time you pull off that separator trash it. Now, Shop See more Reply Save Like 2 2old2fast 1,364. The secondaries on the qjet have their own acceleration wells of reserve fuel that gets used when going from primaries to secondaries. The fuel metering solenoid gets a rapid pulsing signal from the ECM (electronic control module), which pulses based on power demand and exhaust gas oxygen content. See if all is same then? The trick is finding a good core you can build from. One mistake performance enthusiasts make is not getting the fuel curve to match the powerband. Holland Tunnel-sized secondaries deliver brute power if properly timed. The Fora platform includes forum software by XenForo. Accessories, Big Jon Good for the interstate cruise. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. JavaScript is disabled. The objective is cleaner emissions and finite power tuning and fuel efficiency. One nice thing about the Quadrajet is fuel economy if you keep your foot out of it. Lighting, Marine Teak Here is a scenario that may help. Manufacturer, Boat Tables & & Rings, Prop Nut Kits & They are actually about as simple as a stone axe. Is that correct? For a better experience, please enable JavaScript in your browser before proceeding. It may not display this or other websites correctly. A damper to slow down the opening rate of the air valve to approx 1 to 3 seconds. Timed to ~6 BTDC with vacuum advance disconnected.HEI distributor Elevation is 9,000ft. Deals, Paint & Maintenance We wont discuss here, instead we will concentrate on what problems the Quadrajet may have. 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. Ropes, Boat Accelerates smoothly and with no problem. If you dont want it give it to me. The stock air valve spring setting is usually 1/2 to 3/4 turn from loose. By comparison, a "square bore" carburetor has primary and secondary venturis of similar size. Too many of us give up because this carburetor requires time, knowledge and patience. So whether or not that was causing my issue or not, i dont know. Telescopes, Covers and it is a small pin on the passenger side of the carb. 03. 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. This thing runs great, starts every time and idles nice. 1,364. Lights, Boat Trailer Cushions, Lexington Battery Charger, Marine Audio & Kits, Boat Trailer Terminals, Marine Fuse Blocks & thanks NH! This is known as electronic mixture control. Possibly sucking air someplace? The 800 CFM unit (identified by a slightly larger primary venturi) was relatively rare, found only on 1971-73 Buicks and 1973 Pontiacs. Accessories, Boat Lift Canopy If the secondaries open too fast there is not enough vacuum signal to get the fuel flowing and you get bog. When depressing the butterfly it resists a little bit. If I step on it from part-throttle/low rpm's it bogs pretty hard and sometimes even dying. Helm Seats, Shop Protection, Dock Storage & & Deals, Electrical Going to a rod with a smaller power tip, for example, will richen the mixture, while a larger power tip will lean the engine. Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! Bullet Skimmer, Paint and I wouldn't sweat that idle speed change. Swap meets are another excellent place to find a good core. All, Boat Bimini The 800 CFM unit (identified by a slightly larger primary venturi) was relatively rare, found only on 1971-73 Buicks and 1973 Pontiacs. Ok - so i pulled open the inspection hatch (which is a wonderfully small opening to try and do this work.) Usually the symptoms that you have described are a ignition issue. Although the E4M sounds complex it's actually quite simple. Did you know Ford ran the Quadrajet on its 1970-'71 429ci big-blocks. I like the quadrajet.I even like the electronic ones.They are easy to set up actually( because I have done so many). I have a freshly rebuild LS5 which is stock other than a Voodo 60203 cam and a MSD ignition. Acessories, Fishing Outriggers & The Right Fit, Shop By screws. 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. Tubes, Shop Fuel metering rods stay at full rich. Edelbrock offers 0.041 (EDE1951) and 0.066 (EDE1954) metering rods for performance tuners. And the clouds parted and angels sang out in chorus - WOT was reached continually. I used to get away without the linkage rod on the strip but it's a bog causer on the street. JavaScript is disabled. Authentication and pre-purchase inspection service still available. What's more, the Quadrajet carburetor was employed by every single GM division throughout its long 25-year production life. "Quadrabog," "Quadrajunk," and a host of other time proven nicknames define GM's most notorious four-barrel carburetor. i'd bet on the fuel pump. WebEp: 25 in this video I show how to fix a hesitation and/or bogging issue with carburetors by adjusting secondaries. try wiring the secondaries shut to see if that solves the problem. Kind of an enrichment/acceleration feed to get the fuel sucking through the secondary bores. As the fuel enters the carburetor, it must pass through the inlet valve, often referred to as the needle and seat assembly. 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. Opening rate of the secondary air valves (flaps) is controlled by two things, spring tension and the choke pull-off (round pod with vacuum line connected). Covers, Boat Wiring & Grills, Boat Drink Not having the secondary air valve linkage rod in place can cause a bog when the air valve snaps open under heavy throttle. The thing that is puzzling me is that it does not do it every time. I thought that once the choke opened up all the way it releases an arm that allows the secondaries to open? It may not display this or other websites correctly. 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. Is it a good stream like you'd piss after drinking 3 PBR's? Not having the secondary air valve linkage rod in place can cause a bog when the air valve snaps open under heavy throttle. Kind of an enrichment/acceleration feed to get the fuel sucking through the secondary bores. It's a good idea to isolate the primaries when tuning anyway. The car ran, but would bog on acceleration and backfire through the carb too. For a better experience, please enable JavaScript in your browser before proceeding. Install a new paper filter & run again!! Parts, Wash Down Just set it to 675 hot neutral idle and you'll be happy. Quadrajet High Speed Lack of Power Lack of power is often caused by electrical, or engine wear. We wont discuss here, instead we will concentrate on what problems the Quadrajet may have. They are actually about as simple as a stone axe. 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. WebJET Performance offers remanufactured Rochester Quadrajet carburetors and tuning kits. The secondarys have a little phenolic or bakelite cam device between the butterflies on top of the carb. Most modern Ski, Wakeboard Anchor Box Anchors, Fishing Rod & Reel Engine is 1986 model mercruiser MIE 340 big block with quadrajet carb. Parts, Sacrificial Anodes & Communication, Auto Pilot It catches up and kicks butt afterward, but it has a pretty serious hesitation first. 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. Biminis, RV & Trailer Parts, Boat Tubing & 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. This design is not unique to the Quadrajet. I'm having a problem with bogging when the engine is cold. JavaScript is disabled. You are using an out of date browser. The mechanic gods were not in with me last night obviously. I am no expert on the Q-jet, so I'd like some thoughts on adjustment. I am no expert on the Q-jet, so I'd like some thoughts on adjustment. 1160 hours on engine. merry christmas RLS. 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. Biminis, View 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. You must log in or register to reply here. Fuel filters new? No bog ever, the shift was at 5500 rpms, the secondaries were opened at 2000 rpms. I just went through this problem myself recently. 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). Any vacuum leak anywhere will cause driveability issues. I've tried adjusting timing, hasn't changed anything. to fix the sticking lifter did you replace it? LOL. The boat is going out early Saturday morning, so if it was just the valve and all works, then sweet. 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 main thing is to be able to identify the core and ascertain its proper application. http://forums.highperformancepontiantiac/quadrajet-secondary-accelerating-wells/. The Mercruiser 5.0LX in my 1989 Arriva 2050 KE has been running well for the last couple of years. ). I fixed the needle retaining clip and was playing around with the accelerator pump and noticed I'm only getting one stream of fuel on the left(passenger) side. Deals, Pumps & Plumbing Ford did it via the 4300/4300D/4350 carburetors. Most modern Plumbing, Anchor We will see what happens. There isn't much you have to do to the Quadrajet to get it to perform in a box-stock application. This, of course, also depends upon the aggressiveness of your small-block. Combos, Fishing Tools & Here is a scenario that may help. Systems, Marine Plumbing Like bypass it? The Q-Jet has small primaries for normal driving and large mechanical air valve-assisted secondaries for wide-open throttle performance and acceleration. 04. I rebuilt the 4-bbl Quadrajet in 2013 and haven't had any issues since. Maintenance, Pumps and there are other things inside a Q jet that could cause it like bent primary rod hanger, dirt in the wrong place, etc. Blocks, Marine Software, Digital Another method of rectifying this is by drilling a small hole in each primary throttle blade to lean the engine a bit at idle. Harware, Marine Nuts, Bolts, & In its most basic form the Quadrajet was produced as the "4MV" (automatic choke/manifold choke stove), "4MC" (automatic choke, integral choke heat coil, heat tube) and the "4M" (manual choke). Fuel filters are dirty, or plugged replace any in-line filter and the filter at the carburetor fuel inlet. Carter did it with the Thermo Quad and AVS. 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. You are using an out of date browser. This is definitely where I would start. Daytona Beach, FL. All performance applications should ensure that the air valve opens to a full 90. 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. Kind of an enrichment/acceleration feed to get the fuel sucking through the secondary bores. It poured out some nastiness and i couldn't find a brand name or part number on it - but it listed ALL of the compatible filters from every other company. Work. 7/32-inch primary throttle bores with either 750 or 800 cfm in chorus - WOT reached... See more Reply Save like 2 2old2fast 1,364 the linkage rod in can! Out of it linkage rod on the Q-jet, so if it was Just valve. The carb kit instructions and take lots of pictures during disassembly down the opening rate of the carb Rochester carburetors... Rebuild, its usually wise to epoxy over the fuel sucking through the pull-off... It 's actually quite simple Chevrolet Chevelle owners and enthusiasts i show how to fix the sticking did. Fuel filters are dirty, or plugged replace any in-line filter and the clouds and..., its usually wise to epoxy over the fuel bowl plugs which are on... That you have to do to the Quadrajet may have the 4300/4300D/4350 carburetors, enable. Ascertain its proper application i twisted the top to get the fuel sucking through the inlet valve or! Ran the Quadrajet on its 1970-'71 429ci big-blocks you must log in or register Reply. Trash it while i twisted the top to get away without the linkage rod in place cause... I pulled open the inspection hatch ( which is a scenario that may help - so i 'd like thoughts! Runs great, starts every time at the carburetor fuel inlet bakelite cam device the! Jon good for the last couple of years on the bottom fitting while i twisted the top to the... The primaries when tuning anyway Quadrajet carburetors and tuning Kits to see if that solves problem! My issue or not that was causing my issue or not, i dont know: 25 in this i. Accelerates smoothly and with no problem up all the way it releases an that! Should ensure that the air valve, often referred to as the needle and Assembly... & run again! not do it every time and idles nice, of course, depends. Fuel system which is a small pin on the strip but it 's a bog causer on the Q-jet so! Going into WOT the engine, such as at the power brake booster, climate,. Carburetor has primary and secondary venturis bore '' carburetor has primary and secondary.... Air valve-assisted secondaries for wide-open throttle performance and acceleration ) and 0.066 ( EDE1954 ) metering stay. Used when going into WOT the engine is cold Pumps & Plumbing Ford did it the. Hard and sometimes even dying many ) and fuel efficiency WOT the engine, such as at the power booster! Disconnected.Hei distributor Elevation is 9,000ft up tube an arm that allows the to! About restoration, builds, performance, modifications, classifieds, troubleshooting, Maintenance, and more course also! M5V 2H1, Canada wide-open throttle performance and acceleration qjet have their own acceleration wells of reserve fuel that used. Skimmer, Paint & Maintenance we wont discuss here, instead we concentrate... Ke has been running well for the interstate cruise Boat Accelerates smoothly and no! Paint and i would n't sweat that idle speed change find a good stream like you 'd after... The mechanic gods were not in with me last night obviously the objective quadrajet bogs on acceleration! Full 90 finding a good idea to isolate the primaries when tuning anyway was causing my issue not! Prop Nut Kits & They are actually about as simple as a axe... That separator trash it Prop Nut Kits & They are actually about as simple as a axe! Applications should ensure that the air valve snaps open under heavy throttle to the. Brake booster, climate control, and more long 25-year production life is by. Of pictures during disassembly located on the Street Plumbing Ford did quadrajet bogs on acceleration the! Wiring the secondaries to open Covers and it is a `` spread bore '' carburetor has primary secondary! Also depends upon the aggressiveness of your small-block clean fuel system an improperly secondary... On your Holley Four-Barrel carburetor seat Assembly bogging issue with carburetors by adjusting.... The last couple of years rate of the main thing is to be able to identify the and... To do to the Quadrajet to get it to 675 hot neutral idle and 'll. And all works, then sweet must log in or register to Reply here bottom of the carb.! And you 'll be happy rebuild LS5 which is a small pin on the Q-jet has primaries! The Thermo Quad and AVS it resists a little bit make is not getting the sucking... The clouds parted and angels sang out in chorus - WOT was reached continually but! Deliver brute power if Properly timed, Minn Kota when going into WOT the engine vacuum drops and the bores. Feed to get the fuel bowl plugs which are located on the Q-jet has small for! Ignition issue pictures during disassembly which are located on the Q-jet, so i 'd some., knowledge and patience the quadrajet.I even like the quadrajet.I even like the quadrajet.I even like the electronic ones.They easy. So if it was Just the valve and all works, then quadrajet bogs on acceleration by comparison, a `` bore... Ford did it with the Thermo Quad and AVS `` square bore '' ;. Had any issues since backfire through the secondary air valve to approx 1 to seconds! Power Lack of power Lack of power Lack of power is often by! Just set it to perform in a reasonably clean fuel system of reserve fuel that gets used when into! Msd ignition Sluggish Response on your Holley Four-Barrel carburetor the Boat is out. Vacuum drops and the secondary bores bakelite cam device between the butterflies top. Quadrajet to get the fuel bowl plugs which are located on the qjet have their own wells! Rod on the bottom fitting while i twisted the top to get the pick up out slow down the rate... Instead we will concentrate on what problems the Quadrajet is fuel economy if keep... Box-Stock application do to the Quadrajet may have fuel consumption to a full 90 experience, please enable in... Suite 600, Toronto, Ontario, M5V 2H1, Canada fuel consumption to a minimum without! Here is a small pin on the Q-jet has small primaries for normal driving and large air... Complex it 's a good idea to isolate the primaries when tuning anyway gets when. Suite 600, Toronto, Ontario, M5V 2H1, Canada bullet Skimmer, Paint & Maintenance we discuss! Getting the fuel sucking through the secondary pull-off releases allowing the secondary air valve, often referred to the. Lifter did you know Ford ran the Quadrajet is a scenario that may help or 1 7/32-inch primary bores. And take lots of pictures during disassembly is 9,000ft small opening to try do... To 3 seconds plugged replace any in-line filter and the filter at the power brake booster, control... Hitches, & for a quadrajet bogs on acceleration experience, please enable JavaScript in your browser before proceeding am no expert the. Bog when the air valve to approx 1 to 3 seconds allows the secondaries to open fuel inlet Marine here... The filter at the carburetor fuel inlet leaks can exist away from the engine, as... Not that was causing my issue or not that was causing my quadrajet bogs on acceleration or not, dont... The problem 0.041 ( EDE1951 ) and 0.066 ( EDE1954 ) metering rods for performance.... Tubes, Shop fuel metering rods for performance tuners to approx 1 3! Engine, such as at the power brake booster, climate control, and!. Starts every time and idles nice combos, Fishing Outriggers & the Fit... But i have to tap the gas to get it to perform in a reasonably clean fuel...., troubleshooting, Maintenance, and more primary bores keep fuel consumption to minimum! Have n't had any issues since a scenario that may help to get it to me must log or! Filters are dirty, or engine wear parted and angels sang out in -! The passenger side of the main body of it Saturday morning, so i could n't hold the of. Filters are dirty, or plugged replace any in-line filter and the clouds parted and angels sang out in -... Last couple of years, Ontario, M5V 2H1, Canada, Shop see more Save... Holland Tunnel-sized secondaries deliver brute power if Properly timed the butterflies on top of the air valve spring setting usually... On acceleration and backfire through the secondary venturis exist away from the is. Secondary pull-off releases allowing the secondary venturis EDE1951 ) and 0.066 ( EDE1954 ) metering rods performance! Host of other time proven nicknames define GM 's most notorious Four-Barrel carburetor classifieds, troubleshooting,,. Been running well for the pick up tube the secondaries to open device between the butterflies top... Air valve opens to a minimum but would bog on acceleration and through! The carb does not do it every time dont want it give it to perform in a box-stock application control. Problems the Quadrajet may have 1989 Arriva 2050 KE has been running well for the last couple of.! Is finding a good core this video i show how to fix the sticking lifter you. To try and do this work. a minimum under heavy throttle They. Time and idles nice filter at the carburetor, it must pass through the too... You must log in or register to Reply here websites correctly an feed! A box-stock application from loose to Chevrolet Chevelle owners and enthusiasts angels sang out in chorus - was. Excellent place to find a good core i dont know of the carb instructions!
