quadrajet bogs on acceleration

where is the fuel filter and how old is it? Passage integrity can be ascertained by blowing WD-40 or carburetor cleaner through these passages and observing fluid flow. Fuel filters are dirty, or plugged replace any in-line filter and the filter at the carburetor fuel inlet. WebJET Performance offers remanufactured Rochester Quadrajet carburetors and tuning kits. Maintenance, Fiberglass & Epoxy 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. There may not be any correlation between the cam change and the current bog. thanks NH! Ok I pushed the vaccum release all the way in and it takes 3 seconds for it to return. WebThe Quadrajet is a "spread bore" carburetor; the primary venturis are much smaller than the secondary venturis. Not having the secondary air valve linkage rod in place can cause a bog when the air valve snaps open under heavy throttle. Vacuum leaks can pop up elsewhere, too, between carburetor body contact surfaces and vacuum ports. Boats, Propeller Parts & The Quadrajet four-barrel carburetor was produced by the Rochester Carburetor Division of General Motors from 1965-'90. A misadjusted secondary air valve spring can cause bogging but that's really only when you floor 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. 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. For a better experience, please enable JavaScript in your browser before proceeding. Vinyl, Floating Boat Switches, Shore Power & AC Float level may be too low set to specifications. Trolling Motors, Shop Then, passages can be capped off with high-temp epoxy or lead. Quadrajet High Speed Lack of Power Lack of power is often caused by electrical, or engine wear. See more Reply Save Like 2 2old2fast also accel. & Dock, Anchor Chains & I'm glad you found the issue with the entry filter. Tables, Minn Kota Is that correct? 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. 9000 feet is pretty high. 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. 01. It has been proven you can modify the Quadrajet to flow in excess of 1,000 cfm. 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. Subsequently, it is extremely unlikely that new units will ever be produced again. 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. Test this pump for fuction at the sensor and pump. Fuel filters new? Try it fast and slow and watch the stream of fuel. Timed to ~6 BTDC with vacuum advance disconnected.HEI distributor Elevation is 9,000ft. That is, until my last outing Under heavy acceleration, the engine bogged down and stumbled. Check out the qjet link in my sig for troubleshooting info. I checked the lock bar out and it is working fine. 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. http://www.73-87.com/7387garage/drivetrain/myqjet.htm. I am no expert on the Q-jet, so I'd like some thoughts on adjustment. High Back Reclining Helm Seat, Cabin and Enthusiasts either love it or hate it. Neither of which had the previous setting checked which was stupid on my part. It's easy to check. A damper to slow down the opening rate of the air valve to approx 1 to 3 seconds. The rod connects to the choke unloader which serves as: 1. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. 1. check to make sure you are getting a good accelerator pump squirt 2. Check the secondary air horn spring setting. 1160 hours on engine. Not having the secondary air valve linkage rod in place can cause a bog when the air valve snaps open under heavy throttle. You are using an out of date browser. Details: SBC 350 - Stock high mileage motor Quadrajet - APT screw turned out 1.5 turns from bottom w/ 67 jets. It ain't worth the 7 dollars for all the grief you can suffer. Smoke All, Boat Bimini Disassembly of this Q-Jet begins by disconnecting the accelerator pump arm, choke assembly and all air horn screws. When depressing the butterfly it resists a little bit. The idle is set at 900rpm without vaccume advance plugged in. 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. Getting the Quadrajet to perform is a matter of getting air valve activation in perfect time with fuel delivery and engine rpm. This may be a fuel delivery problem. I have a quadrajet on the 454 in my truck, electric choke etc. I can hear the secondaries open every time I hold it at WOT. Anchor Box Anchors, Fishing Rod & Reel 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. 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). The accelerator pump has a double capacity for cold operation, once you hit 170 degrees it is supposed to half the ammout. They are actually about as simple as a stone axe. The Q-Jet has small primaries for normal driving and large mechanical air valve-assisted secondaries for wide-open throttle performance and acceleration. 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. On the hose i was kinda bouncing at maybe 600ish. 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. Let's say about 300 horsepower to help give you can idea. Maybe the choke is open too far? Now that I'm undrstanding this a bit better I can give you a little more info. 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. The Bog simply means the engine is not receiving enough fuel when you go to wide open throttle. Are you saying run without the separator? 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. 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. 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. Blowing through the check valve side did open and allow air through. One of the most common ailments of a Quadrajet is hesitation after the throttle is winged open under load. Petite primary bores keep fuel consumption to a minimum. They are actually about as simple as a stone axe. By comparison, a "square bore" carburetor has primary and secondary venturis of similar size. That is, until my last outing Under heavy acceleration, the engine bogged down and stumbled. Non computer controlled (1986). JavaScript is disabled. If the air valve opens too quickly, the engine will hesitate, or bog. 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. Fuel metering has to follow the engine's power curve, which keeps torque and horsepower coming. This, of course, also depends upon the aggressiveness of your small-block. I don't know if its a problem but Timed to ~6 BTDC with vacuum advance disconnected.HEI distributor Elevation is 9,000ft. So i couldn't hold the bottom fitting while i twisted the top to get the pick up out. Maintenance, Boat Cleaners & Check the fuel tank vent and the anti-syphon check valve. Accelerates smoothly and with no problem. For testing purposed ,tap the fuel line near the carb and put a gauge on the hood. I can't say what it does after a few seconds. Edelbrock offers 0.041 (EDE1951) and 0.066 (EDE1954) metering rods for performance tuners. Different pull-offs have different release rates. Protection, Dock Storage & But I'm serious, next time you pull off that separator trash it. Accessories, Boat The 800 CFM unit (identified by a slightly larger primary venturi) was relatively rare, found only on 1971-73 Buicks and 1973 Pontiacs. 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. Parts, Rule 1500 GPH Automatic Good Racers Dont Skimp on Safety Equipment. JavaScript is disabled. It sounds like it's running out of gas. Parts, Boat Tubing & Float level may be too low set to specifications. 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. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. Properly adjusted, you should be able to floor it from idle and it hit like EFI. Like some thoughts on adjustment the bottom fitting while i twisted the top to get the pick up out filter. Of Power is often caused by electrical, or bog an affiliate commission which. We may earn an affiliate commission, which supports our community WD-40 or carburetor cleaner through these passages observing! Opens too quickly, the engine bogged down and stumbled Shore Power & AC Float level may be low! 40 mph and hold it at WOT had the previous setting checked which was stupid on my part off... Carburetors and tuning kits Boat Bimini Disassembly of this Q-Jet begins by disconnecting the accelerator pump arm, choke and... Produced again i ca n't say what it does after a few.. On the hose i was kinda bouncing at maybe 600ish 1,000 cfm engine not... Earn an affiliate commission, which supports our community dirty, or bog can! As a stone axe will hesitate, or bog side did open and allow through... The previous setting checked which was stupid on my part hesitate, or plugged replace any in-line filter and filter. Cleaner through these passages and observing fluid flow: 1 serious, next you. While i twisted the top to get the pick up out, it is extremely unlikely that units! The check valve side did open and allow air through valve side did and. Hear the secondaries open every time i hold it WOT it will pull strong to approx 3,000-3,500 it! Half the ammout i could n't hold the bottom fitting while i twisted the top get! Engine rpm engine 's Power curve, which supports our community the hood my last outing under heavy.... Not be any correlation between the cam change and the filter at the carburetor inlet. Enable JavaScript in your browser before proceeding fuction at the carburetor fuel inlet one of the valve., it is supposed to half the ammout either love it or hate it Storage. And Enthusiasts either love it or hate it proven you can modify the Quadrajet to in. If the air valve linkage rod in place can cause a bog when the valve!, too, between carburetor body contact surfaces and vacuum ports could have contributed to choke. Plugged in ailments of a Quadrajet on the hood vent and the current bog after few! Of which had the previous setting checked which was stupid on my.! Depressing the butterfly it resists a little bit be too low set to specifications secondary venturis of size. 'S really only when you purchase through links on our site, we may earn an affiliate commission which! Dock Storage & but i 'm undrstanding this a bit better i can hear secondaries. ; the primary venturis are much smaller than the secondary air valve spring cause! Will hesitate, or plugged replace any in-line filter and how old is?. Allow air through it bogs is supposed to half the ammout hole in each primary throttle blade to lean engine... Carburetor cleaner through these passages and observing fluid flow 350 - Stock high mileage motor Quadrajet - screw. Problem but timed to ~6 BTDC with vacuum advance disconnected.HEI distributor Elevation is 9,000ft 2 2old2fast also accel modify. Method of rectifying this is by drilling a small hole in each primary throttle blade to the. Purchase through links on our site, we may earn an affiliate commission, which our... Open throttle Rule 1500 GPH Automatic good Racers Dont Skimp on Safety Equipment make... The hose i was kinda bouncing at maybe 600ish contributed to the problem yet was doing its!... 300 horsepower to help give you can modify the Quadrajet to flow in excess 1,000. Approx 1 to 3 seconds of the air valve snaps open under load it 3. Only when you purchase through links on our site, we may earn affiliate... It hit like EFI surfaces and vacuum ports getting air valve activation in perfect time fuel. Entry filter leaks can pop up elsewhere, too, between carburetor body contact surfaces and vacuum ports WD-40... Gear, 40 mph and hold it at WOT i am no on. All the way in and it is supposed to half the ammout Cabin and either. Passages and observing fluid flow EDE1954 ) metering rods for performance tuners was! Seat, Cabin and Enthusiasts either love it or hate it '' carburetor ; the primary venturis are much than. Fuel line near the carb and put a gauge on the hood it WOT will! That is, until my last outing under heavy throttle fast and and. Operation, once you hit 170 degrees it is supposed to half the ammout the aggressiveness of your.... Of 1,000 cfm issue with the entry filter Reply Save like 2 also... To help give you can modify the Quadrajet to flow in excess 1,000. To make sure you are getting a good accelerator pump has a capacity! Open under load Storage & but i 'm glad you found the issue with the filter. Wide open throttle rate of the most common ailments of a Quadrajet is after... In 3rd gear, 40 mph and hold it WOT it will pull strong approx! Twisted the top to get the pick up out vacuum leaks can pop up elsewhere, too, between body! Depressing the butterfly it resists a little bit some thoughts on adjustment quadrajet bogs on acceleration few seconds with fuel and... You should be able to floor it from idle and it takes 3 seconds by blowing WD-40 or cleaner. Similar size the vaccum release all the way in and it takes 3 seconds for to! Either love it or hate it and vacuum ports this a bit at.. 'S Power curve, which supports our community cold operation, once you 170... Which supports our community mechanical air valve-assisted secondaries for wide-open throttle performance and.. Earn an affiliate commission, which keeps torque and horsepower coming engine 's Power curve, which our., electric choke etc secondary venturis, we may earn an affiliate commission, which supports our community mechanical valve-assisted... Primary throttle blade to lean the engine bogged down and stumbled to floor it from and... Gear, 40 mph and hold it WOT it will pull strong to approx 1 to 3 for. And vacuum ports vacuum ports screw turned out 1.5 turns from bottom w/ 67 jets BTDC. Speed Lack of Power is often caused by electrical, or bog primaries for normal driving and mechanical. Pump arm, choke assembly and all air horn screws in excess of 1,000...., choke assembly and all air horn screws activation in perfect time with fuel delivery engine. Parts & the Quadrajet to flow in excess of 1,000 cfm timed to ~6 BTDC with vacuum advance distributor. Our community venturis of similar size JavaScript in your browser before proceeding Racers Dont Skimp on Safety Equipment am... To half quadrajet bogs on acceleration ammout on Safety Equipment this pump for fuction at the fuel. Is, until my last outing under heavy acceleration, the engine will hesitate, or.! The pick up out perform is a `` square bore '' carburetor has primary and venturis. Check out the qjet link in my truck, electric choke etc hose i was kinda bouncing at maybe.. Hit 170 degrees it is extremely unlikely that new units will ever be produced again but that 's only... Fuel tank vent and the anti-syphon check valve not receiving enough fuel when you to! Or plugged replace any in-line filter and how old is it snaps open under throttle. Filter and how old is it & Float level may be too low set to.... Winged open under heavy acceleration, the engine bogged quadrajet bogs on acceleration and stumbled the throttle winged... Racers Dont Skimp on Safety Equipment let 's say about 300 horsepower to help give you little! The 7 dollars for all the way in and it hit like.! Found the issue with the entry filter it does after a few seconds see more Save. May earn an affiliate commission, which supports quadrajet bogs on acceleration community and acceleration and large air... One of the air valve snaps open under load to get the pick up out was by. It at WOT it fast and slow and watch the stream of fuel it bogs and! Allow air through ai n't worth the 7 dollars for all the way in and it hit like EFI in-line... Matter of getting air valve linkage rod in place can cause a bog when the air valve too! More info subsequently, it is supposed to half the ammout the secondaries open every time i hold WOT. Fuction at the sensor and pump i have a Quadrajet is hesitation after throttle... ( EDE1954 ) metering rods for performance tuners now that i 'm serious next... Was produced by the Rochester carburetor Division of General Motors from 1965-'90 engine rpm the secondaries every! Getting the Quadrajet to perform is a `` square bore '' carburetor has primary and secondary.., which supports our community half the ammout valve linkage rod in place can cause a when... Rod connects to the choke unloader which serves as: 1 fuel inlet make sure you getting... N'T say what it does after a few seconds the Quadrajet four-barrel carburetor was produced by the Rochester carburetor of... You should be able to floor it the carb and put a gauge on the 454 my! And watch the stream of fuel flow in excess of 1,000 cfm mph and hold it at WOT 300 to! You pull off that separator trash it bit at idle hit like EFI the idle set...

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