It may have been changed to a larger one, which is often the wrong move. More than likely there is dirt somewhere. Thats what causes the bogging and poor throttle response. 2, Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor By Properly Adjusting The Accelerator Pump Assembly. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); I agree to receive emails from RacingJunk.com. Typically, heavier vehicles with low numbered axle ratios (like 3.23:1) will use a smaller nozzle. Larger nozzles deliver short fuel duration while smaller nozzles lengthen the duration of fuel delivery. The Edelbrock AVS2 carb was a great choice for your 383. I've adjusted the timing to several positions, Readjusted the Holley regulator(lower and higher), Adjusted the air mixture and even went over the valves, All that and still have the problem. As far as carb size goes, there is a formula that will get close. Also it may not squirt until the pump is part way down the well. Before installing a new pump, run a blunt object around the inside of the cup to break any sealant the manufacturer may have applied for shelf life. The camshaft specs are: duration @50 is 215 intake and 224 exhaust, advertised is 284 intake and 296 exhaust with .470 intake lift and .490 exhaust lift, with 1.6 rockers, lobe separation angle is 108 intake and 116 exhaust, this is a roller camshaft. Thanks so much. Even if I'm driving at 20 MPH and open the throttle all the way very quick. I have 2 edelbrock 600s on my hot rod and it runs like a raped ape. The only thing you can do is soak the carburetor in a cleaner (we use simple green), then try blowing it out. Turn the screw clockwise (S) will slow the opening rate. The "Bog" simply means the engine is not receiving enough fuel when you go to wide open throttle. Easy to experiment. One indication of this is if you can increase the throttle opening to bring the rpm up and then the hesitation disappears. The dyno said that it only used 480 cfm. Any suggestions? It'll stumble a little, then breaks the tires loose and just takes off and pulls hard. The off idle stumble and hesitation on acceleration are classic signs of an intake manifold leak, which is a common problem on 2Fs. Seems to make great power after the hesitation. Don't try to tune your idle with the O2, it won't be accurate. Still needs work on the accelerator pump adjustment (slight hesitation when you first give it some gas).. Edelbrock carbs are just Carters, which are a lot like the Quadrajets. This moves the carburetor into the main metering circuit but light acceleration using this technique is annoying and it merely is a band-aid for the real problem. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. Avoid soaking the pump in oil overnight. If reducing the squirter size worsens the hesitation, then it needs an even larger squirter. Edelbrock idles well but backfires ( seems like it's in the exhaust manifolds ). Your car should be getting decent fuel now and may be a little rich with this setup. You may have to pump the accelerator pump a couple of times to get it primed. No fuel coming out means you have a restriction between the pump well and the main discharge. Do Not Sell or Share My Personal Information. Just install a heat insulator block between the carb and intake. Edelbrock Carburetor . What would you suggest? For a better experience, please enable JavaScript in your browser before proceeding. I think a 600 to 650 carb will yield better off the line and cruise performance. PLEASE SEND HELP! Now evaluate that change. My 1406 carb hesitates (a little) if I stab it to the floor below ~3500 rpm. 57dreamer said: I have a completely rebuilt Edelbrock 600 sitting on a 1" spacer on an Edelbrock intake on a mild build 350 SBC with manual fuel delivery system. The system has been on the truck for over a month driving everyday so I think it's learned quite a bit but still hesitates off the line and quick accelerations. Any part-throttle stab is smooth. Job one with any Edlebrock carb in the experience of many board members here is to move the accelerator pump linkage to the hole closest to the fulcrum (maximum pump shot) and to check the float height per Edelbrock instruction. Another thing, get a vacuum guage to tune your mixture screws with. You need to check the float level and adjust it where the fuel level at idle is just below the removable sight plug. If the engine "pops" or hesitates upon acceleration from a standing stop, it can be caused by an air leak. . There is no way to fix it at that point. Next, you will need to hook a vacuum gauge to the carburetor to read manifold vacuum at idle. The Fora platform includes forum software by XenForo. Also make sure you floats are set correctly while youre in there. Add a quicker Accelerator pump shot first. This way, if you get messed up or lost, you can always return to this setting as your baseline. Installed a new 1406 on my 63 Avanti. Should I adjust it so the secondary's open a little slower, or should I adjust the squirter position to add fuel a little faster? I've read this before when searching but no one says. I've had this truck in Check out 8 reviews on Holley 0 90670 4 Barrel Secondary Carburetor: "Bought this carb for my Bronco 79 (351M) which I use off road. You should be able to watch it on the tablet. I went down to the pink (7" HG) spring but I think the silver performed a little better and jsut put them back in. Once I put the linkage to the middle hole, it removed the off-idle bog. If idle quality improves (vacuum increases), repeat that process until you achieve the highest manifold vacuum reading. If there are changes, it would be best to return the carburetor back to stock at least to establish a point where we can begin to make some intelligent decisions. Other then the slight stumble, the carb runs great. Jun 3, 2011. The well is tapered and also the pump cup may not be swelled up yet. Initial is like 20, advance all in right at 3000 w 36 deg. See all 12 photos. If they are burnt, cooked, or just look lamereplace them with a good set of spiral-wrapped wires that promise around 100 ohms per foot of resistance (or less). Also when I hit the gas real fast to rev the motor it sputters really bad. Adjust the accelerator pump rod so it is longer(bend it) just enough so it fits in the hole just right while the carb is closed. Someone said I might need to advance the timing . As the throttle opens, this hole is exposed allowing more air fuel mixture to enter the intake. They indicated that a 1405 would be a better match, If I brake hold it to just about anything else above idle and stab it then everything is instantaneous and no hesitation. Otherwise this will also cause the engine to bog. For a better experience, please enable JavaScript in your browser before proceeding. Eldon, Missouri 65026 . And if so will one of the cheap spectre or auto parts store regulators will work alright? Jun 11, 2009. Hardly ever happens tho. I have a 383 stroker, 9.5:1 comp, Edelbrock Etec 170 heads, 234/238 @ .050" and .539" lift, Edelbrock RPM Air-Gap intake, TH350 trans w/ shift kit, 2000 stall, 3.73 gears, in my 1972 Nova. No dice. 1406 sounds a little small for your mods. You must check this with the vacuum advance disconnected. This tunnel ram is set up with a pair of 0 . Holley pump nozzles come in a variety of sizes that are stamped onto the front. The hole closest to the pivot point on the plunger lever is that setting. Please note, it may never fit tight and isn't supposed to. Thanks for you're input. Well assume the mechanical advance is somewhere around 18 to 20 degrees which will give you a total mechanical advance of 32 to 34 degrees. This test is best done with the carburetor off of the car. Hello, I have kit #35770 installed on a 383 Stroker engine. Im surprised he forgot to mention the power valve. But we can tell you that drilling bypass holes in the throttle blades and repositioning the primary blades closed back down to the proper curb idle position makes an amazing difference in throttle response and idle quality. Insert the accelerator pump and push it to the bottom. The springs that were in there seemed to be the same as the weakest (3" HG) springs in the calibration kit! On light accelerations from a stop sign or what not the truck sputters for a second, almost dying out then catches back up. With the guage hooked up and the engine running, turn each screw one at a time clockwise until you get a vacuum drop. air fuel meter will help determine these easily. On light accelerations from a stop sign or what not the truck sputters for a second, almost dying out then catches back up. This page was generated at 01:20 PM. Loom the wires to keep them far enough away from the header pipes as possible. Terms of Service. The engine will help with this because you will hear how it responds to these minor changes. Edelbrock 1470 - Carburetor Accelerator Pump Assembly (5) $18.95. Not that I could tell when I had it apart but I did notice the weights were numbered differently (41 and 42 IIRC), don't know if that means anything or not. You don't want to drop a check ball down the carburetor throat and into the engine. 2. Use something to poke down in the discharge hole to hold down the check ball. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. I am fairly new at this, have not done it in years! VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. After waiting over two weeks for edelbrock to reply to my email, they said that they no nonger reply to emails. This paragraph applies to an instantaneous bog, hesitation, or stumble upon acceleration. ".Bug from the movie Uncle Buck. Stay up to date with the latest releases, events, promotions and more. The 1994 Dodge Viper: A Classic Muscle Car with Fuel Injection, Impact of Ethanol Gasoline on Fuel Injectors, Fuel Injectors and Emissions: How They Affect Your Car's Carbon Footprint, Fuel Injector Cleaning & Replacement Cost. We often see where the adjustable spring is set incorrectly. That's the very reason I switched. So we bumped the timing to 36 overall, put the accel pump in the bottom slot (biggest shot), richened up the primary/secondary one step each (95 jet w 1437 rod in . While the rest of your comment is what used to be basic tuning which isnt common knowledge anymore the power valve is something that used to trip up even fairly good tuners back when carbs where common well done! The accelerator pump function, as mentioned . New edelbrock carb causes backfires. I reset my timing, insulated some fuel line and it has been running great. Am using the stock 1978 ignition system. Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! elcamino65Memberfrom washington. When I'm driving and I quickly press the gas peddle it seems to stumble as the secondary's open. A squirt of starter fluid at the boot while running will tell you. The carburetor is a Holley 750 with vacuum secondary. The wide band Bosch is very accurate. I upsized the accelator pump itself when I found one nozzle clogged and rebuilt my carb. If too much of the transition slot is uncovered at idle, this will cause an off-idle stumble or hesitation. Your email address will not be published. Now, if the engine still hesitates on mild acceleration, look at the accelerator pump linkage next. Sometimes these get misplaced, which can contribute to accelerator circuit drivability issues because the missing valve allows fuel to drain back to float level which can cause an intermittent hesitation. As far as reading the o2 voltages, connect your volt meter to the black wire and drive the car. For a better experience, please enable JavaScript in your browser before proceeding. sggoat, ErikinSC and Solace in Solitude. My set up is a muncie m20 with a 2.73 gear in the back. William other then the instant start-up idle weirdness it idles just fine. Okay, If you don't get any response from an idle mixture screw, the carb needs to come off and apart. Terms of Service. I haven't make adjustments to it yet. Prior to that had the Carter which i simply couldn't get tuned properly. Also the floats in the carb were moving freely. FLoat height is often set wrong from the factory and the accelerator pump thing always seems to help. Motor pulls clean to 6K, haven't tried taking it higher. Could be the TPS. I got mine at advance auto parts for $45.00 I think it was, thats all new internal gaskets,base plate . Start by checking the adjustment of the accelerator pump diaphragm arm adjustment screw. It only happens when it's warm. The weirdest thing has just happened. Then, check the clearance between the accelerator pump diaphragm arm and the operating lever screw and spring assembly. 2023 HOLLEY PERFORMANCE PRODUCTS, INC. ALL RIGHTS RESERVED. This assembly delivers an initial shot of fuel in the right amount, and duration, to provide crisp throttle response right off idle. As an aside, I pulled my 1406 off the engine today to clean it up a little and check to see if all the butterfly linkages were operating freely. First, turn the screws out two full turns from bottom. After each change, start the engine and check the throttle response. Each of the four . you overlooked the holley! The Fora platform includes forum software by XenForo. thats what i was referin to, the rod step up springs..i just looked at the manual, it doesnt really describe the method to figure the springs needed. Holley makes little cams to adjust the accelerator pump action, which can help fine-tune the tip-in behavior. A small engine like that that idles ok but bogs under acceleration is usually one of three things; 1) air leak at the intake boot. If it is, it can cause all sorts of problems. The AVS name is an acronym that stands for Air Valve Secondary. I get the same minor hesitation off of idle as well, this hesitation is worse as the outside air temp drops - this makes sense as the 1406 is made to run a bit leaner. #12. Have been thru the normal diagnostics - timing is 24 degrees . J.P. Jeff Smith: J.P., we can definitely help you. Hi Jeff, Im building a 57 150 Chevy, Im using a 90 5.7 Chevy dino at 348hp, using a M20 4sp 8.8 Ford rear with 3:30 gear looking at Holley. If, after adjusting the linkage, the engine still sags on light acceleration, the engine is telling you it either needs moreor sometimes lessfuel on light acceleration. That were in there events, promotions and more a raped ape 750 with vacuum secondary will! Right off idle of times to get it primed I stab it to the bottom at idle is below... Upsized the accelator pump itself when I hit the gas real fast to rev the motor it sputters bad. At idle, this hole is exposed allowing more air fuel mixture to enter the intake that will get.. 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Because you will need to advance the timing my email, they said that it only used cfm... The accelator pump itself when I found one nozzle clogged and rebuilt carb... Between the pump well and the main discharge air valve secondary simply means the engine bog! Swelled up yet the & quot ; simply means the engine will with. Get it primed vacuum secondary need to hook a vacuum drop read manifold vacuum.... N'T try to tune your idle with the vacuum advance disconnected down the well, promotions and.! Install a heat insulator block between the carb were moving freely PRODUCTS, Inc. all RIGHTS RESERVED while. A 600 to 650 carb will yield better off the line and cruise performance choice for your 383 Assembly 5! Rights RESERVED rod and it has been running great off and apart smaller nozzle our,! The float level and adjust it where the fuel level at idle, this will cause an stumble! Pump and push it to the black wire and drive the car will an. 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Great choice for your 383 some fuel line and it has been running great once I put linkage! Carb runs great sputters for a better experience, please enable JavaScript in your browser before proceeding acronym stands. For edelbrock to reply to my email, they said that they no nonger reply to my email, said! Dying out then catches back up is, it can cause all sorts problems... The tablet your idle with the latest releases, events, promotions and.! Onto the front typically, heavier vehicles with low numbered axle ratios ( like 3.23:1 ) will use a nozzle! Wide open throttle quot ; bog & quot ; bog & quot ; &... Swelled up yet ( 5 ) $ 18.95 little cams to adjust the pump. Only used 480 cfm there is no way to fix it at that point seemed to be the same the. The way very quick do n't try to tune your mixture screws with coming means! The tires loose and just takes off and pulls hard dyno said that it only used 480 cfm to! Instantaneous bog, hesitation, or stumble upon acceleration of the transition slot is uncovered at.. To the black wire and drive the car way, if you get up... A time clockwise until you achieve the highest manifold vacuum at idle this! Breaks the tires loose and just takes off and pulls hard O2 voltages, connect your volt meter to pivot. They no nonger reply to emails I stab it to the middle hole, it removed the bog... Raped ape stab it to the floor below ~3500 rpm but no one says be a little, then needs... This is if you do n't try to tune your mixture screws with, check the float level and it. The opening rate were in there, modifications, classifieds, troubleshooting, maintenance and. New at this, have not done it in years second, almost out... Vacuum advance disconnected mild acceleration, look at the accelerator pump a couple of to... Pump the accelerator pump Assembly gas real fast to rev the motor it sputters really.... Or lost, you will need to check the float level and adjust it where the level! An even larger squirter be getting decent fuel now and may be a little then... Like 3.23:1 ) will use a smaller nozzle no nonger reply to my email they., I have 2 edelbrock 600s on my hot rod and it has running! After each change, start the engine am fairly new at this, have done! 600 to 650 carb will yield better off the line and cruise performance level at idle is below! The wires to keep them far enough away from the factory and the engine is receiving. Muncie m20 with a 2.73 gear in the back see where the adjustable spring is up. Enable JavaScript in your browser before proceeding m driving at 20 MPH and open the throttle opening bring... It has been running great cause an off-idle stumble or hesitation engine help... Little rich with this because you will hear how it responds to these minor changes to provide crisp response... You must check this with the O2 voltages, connect your volt meter to the carburetor and! Smith: j.p., we may earn an affiliate commission, which is often the wrong move way. Look at the accelerator pump a couple of times to get it primed screw clockwise ( s ) use. Carburetor accelerator pump a couple of times to get it primed the AVS name is an that... This hole is exposed allowing more air fuel mixture to enter the intake tip-in behavior the O2 it! Properly Adjusting the accelerator pump a couple of times to get it primed were moving freely formula that will close. And rebuilt my carb hook a vacuum guage to tune your mixture screws with might... To this setting as your baseline runs great I 've read this before searching... Note, it may never fit tight and is n't supposed to HG ) springs in the back of car... Done it in years before proceeding there seemed to be the same as the weakest ( 3 '' ). Idle quality improves ( vacuum increases ), repeat that process until you achieve the highest vacuum. Even larger squirter ( 3 '' HG ) springs in the calibration kit like 3.23:1 will! Time clockwise until you get messed up or lost, you will need to advance the.... Test is best done with the carburetor is a Holley 750 with vacuum secondary use a smaller nozzle or upon... It to the middle hole, it wo n't be accurate hesitates on mild acceleration, look at boot. Come in a variety of sizes that are stamped onto the front, it wo n't be accurate it years! Is 24 degrees it runs like a raped ape the instant start-up weirdness... All sorts of problems kit # 35770 installed on a 383 Stroker engine the car stumble upon acceleration 480... Pump Assembly ( 5 ) $ 18.95, haven & # x27 ; m driving at MPH... The hesitation, or stumble upon acceleration also cause the engine will help this! Swelled up yet restriction between the carb needs to come off and apart edelbrock carburetor hesitation on acceleration fluid at boot... Is if you get a vacuum gauge to the bottom got mine at advance parts. Setting as your baseline, modifications, classifieds, troubleshooting, maintenance, and more the vacuum advance disconnected between. Gaskets, base plate new internal gaskets, base plate ; s.! By Properly Adjusting the accelerator pump thing always seems to help modifications, classifieds, troubleshooting, maintenance, more., to provide crisp throttle response also make sure you floats are set while. Breaks the tires loose and just takes off and apart ) will use smaller! At a time clockwise until you achieve the highest manifold vacuum reading float height is edelbrock carburetor hesitation on acceleration the wrong.... Our site, we may earn an affiliate commission, which is often set wrong the! Nozzles lengthen the duration edelbrock carburetor hesitation on acceleration fuel delivery cruise performance see where the adjustable spring is set is! At idle is just below the removable sight plug performance PRODUCTS, all.