The pump well fills with fuel through the slot on the side of the pump well. William Power valve is probably opening because that rough idle camshaft is only allowing the motor to make 4 or 5 inches of vacuum.if thats the case try a 3.5 valve if your gauge is showing 4, 4.5 if 5 on the gauge etc..theres a small Allan set screw in the bottom of the base plate to allow you to open the secondaries at idle (slightly!) If youre using a size #37 nozzle or higher, you will also need to upgrade to a 50cc pump diaphragm assembly, Holley PN 20-11. Use something to poke down in the discharge hole to hold down the check ball. At normal cruising no backfiring. 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). They told me the 1406 is not recommended for the 7501 RPM Air Gap manifold, the carb may not keep up with the manifold. The only thing you can do is soak the carburetor in a cleaner (we use simple green), then try blowing it out. It doesn't take much because the carburetor material is much softer than the stainless steel check ball. JavaScript is disabled. (Image/Holley). Sounds like your on to something! The well is tapered and also the pump cup may not be swelled up yet. Okay, If you don't get any response from an idle mixture screw, the carb needs to come off and apart. This will be our starting point. . Edelbrock 1470 - Carburetor Accelerator Pump Assembly (5) $18.95. The Edelbrock Performer series #1406 & #1411 carburetors are calibrated 2% lean for fuel economy and in most cases, will not function properly on Performer RPM & Torker style manifolds. 2, Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor By Properly Adjusting The Accelerator Pump Assembly. We transferred the new Edelbrock intake and carb to the new engine. You will find this passage just above the idle mixture hole inside the bore. 10 positive effects of population growth on economic development Making adjustments to the accelerator pump assembly are simple once you understand how the system works. Makes a poping or pinging sound not a real loud backfire. If you slowly and smoothly push the accelerator down it revs up fine with no hesitation. I'd put a regulator on there anyway just to make sure thats not an issue. She stumbles and hesitates under normal acceleration. Maybe ground on 'em or filed 'em? make sure it has only enough stroke to not bottom out at WOT. I've tried messing with the accel pump shot but going up or . The Edelbrock system I believe is a narrow band system. I have an edelbrock 1406 that when i dump the clutch it bogs and stumbles really bad. I adjusted the linkage to the accelerator pump (as Edelbrock site recommended) and it seemed to improve the hesitation / bog, but it still is there. If you are installing a #40 or larger pump nozzle you will need to replace the screw with Holleys hollow pump nozzle accelerator screw. Hardly ever happens tho. I was driving my truck the other day and it felt as though it was running out of gas. Its very hard to tell which way to go in these circumstances so you just have to take an educated guess. Now, if the engine still hesitates on mild acceleration, look at the accelerator pump linkage next. Keep in mind theres a small a gasket and metering needle underneath the nozzle. 440 stumbles off idle only briefly but just annoying enough to want it cured. If you loosen the screws on the front of the carb at the base plate 1/4 turn and it doesn't change idle speed, go back in and go 1/4 turn tighter than when you started to see if it drops idle. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); This site uses Akismet to reduce spam. If I go from a stop with mid throttle, she takes off smoothly right away with . It has a flat spot/hesitation before taking off. Also the floats in the carb were moving freely. Rhansen. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. what states require consummation of marriage; new milford ct police scanner; reply to opposition to motion to compel california; This opens the throttle blades to uncover what is called the transition slot. posted 09-08-2005 04:44 PM. The bigger ball resides in the main discharge. Another thing, get a vacuum guage to tune your mixture screws with. If your vehicle only seems to hesitate in top gear, or over about 45 mph, you may have a problem with the lock-up clutches in the torque . A forum community dedicated to hot rod owners and enthusiasts. Use a 0.015 feeler gauge to make sure the adjustment is correct. Options. And that is measured at wide open throttle using a feeler gauge. As you move the pump up, the well will fill up using the slot described earlier. I believe this was from the previous owner trying to get the truck passed for emissions testing. Accelerator pump nozzles come in a variety of sizes. If you can't get it to seal, then someone probably beat the you know what out of it, thus ruining the carburetor. I adjusted the low and high as directed by turning set screw until engine lugged down then turned one complete turn counter clockwise. Hey guys Q; My AVS2 runs fine, however when I am on higher speed (70 MPH and up) it starts to hesitate when I step on the gas as well.it just stops performing..what could the probleem be? It helped alot, due to both nozzles working. Your car should be getting decent fuel now and may be a little rich with this setup. It idles with a heavy lope like it has a big cam in it and it will burn my eyes if you let the engine idle inside the garage. I think it is hesitating on the transition to secondarys. In addition to this lack of power, a vacuum leak can also cause the engine to idle roughly or even stall. The fuel pump will be drawing air instead of fuel, leaning out the mixture. Edelbrock idles well but backfires ( seems like it's in the exhaust manifolds ). Carb: factory rods and jets, springs. The Edelbrock tuning grid is formed into four quadrants, or squares. Just some information for interested parties, the Thunder series has an adjustable air dam mounted above the secondaries. . where can I find a chart /spreadsheet that show those items, jets/ squiters/ etc as listed in th e article, for all other holley 600/650/750 etc single an double pumpers. does edelbrock make a 2 barrel carburetor Also when I hit the gas real fast to rev the motor it sputters really bad. I like the sound of bumping the timing. Adjust it until there is zero clearance between the throttle linkage and the accelerator pump arm. There are three main components of the accelerator pump assembly that consist of the pump diaphragm, pump cam and pump nozzle. Posted: Jun 2, 2020. I followed Pony Carbs timing instruction to the letter and the problem continues. "Do you know how whipped an engine has to be to blow that loud? Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! A wise tuner once said that 75 percent of all carburetor problems are really ignition related. We just need to run you through eliminating the problem area. 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. Incorrect adjustment is the typical culprit. Polishing the pump well with crocus cloth will also help. It may not display this or other websites correctly. It's set up the way it cam out of the box other then the idle and idle mixture settings. Edelbrock 600 CFM carb, #1405. Hello, I have kit #35770 installed on a 383 Stroker engine. does edelbrock make a 2 barrel carburetor 19 3407 . My neighbors vette had all kinds of heat issues, even with an aluminum manifold and electric fan. $385.95. 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. Finally, with a big cam, what can often occur is that the curb idle adjustment has to be cranked open a great amount to maintain the idle speed. 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. Discussion in 'The Hokey Ass Message Board' started by elcamino65, Jun 29, 2011. The accel pump isn't hard either but you have to take the top of the carb off. One indication of this is if you can increase the throttle opening to bring the rpm up and then the hesitation disappears. You dont want to deliver too much fuel too soon, or to little fuel too late. This will cause your engine to lag, stumble, or hesitate. Just install a heat insulator block between the carb and intake. We often see where the adjustable spring is set incorrectly. Add a quicker Accelerator pump shot first. Brand new Edelbrock AVS2 series 650cfm carb. Also, check to make sure the vacuum advance diaphragm is not leaking vacuum. I too had bog problems with my 1406. And i put a 1470 accelerator pump in . 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. Some may use only a check weight which has a pointed end that fits into the hole restricting the fuel. If too much of the transition slot is uncovered at idle, this will cause an off-idle stumble or hesitation. I have an autolite 2100 that I got from Pony Carbs, put it on a 302 V8. My 1406 carb hesitates (a little) if I stab it to the floor below ~3500 rpm. I was curious about the base setting on those. New edelbrock carb causes backfires. Seems to make great power after the hesitation. ). This will let you inspect the spark plugs and also will help to make sure there isnt a bad cylinder. If it still bogs, you probably need a bigger squirter. Start by increasing the fuel nozzle size up by three sizes. Often the diaphragm is ruptured and the mech sets the idle mixture rich to compensate for the leak. He couldnt fit a spacer under the carb (my dad made a wooden one just for test purposes). You dont need to drill throttle plates. On light accelerations from a stop sign or what not the truck sputters for a second, almost dying out then catches back up. What would you suggest? Prior to that had the Carter which i simply couldn't get tuned properly. Starts right up even after hot start. Your email address will not be published. I should check the jets now too. Start by checking the adjustment of the accelerator pump diaphragm arm adjustment screw. Carb: edelbrock performer series 600 cfm electric choke (1407). Adjust secondary blades open a touch more, then you can reduce primary throttle setting. But I still had a bog at about 1/4 to 1/2 throttle. 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. Good job. This carburetor is best suited for propane or fuel injection. 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. Notify me of follow-up comments by email. First check for any vacuum leaks anywhere near the carb or elsewhere. The gap or clearance between the linkage and accelerator pump arm must be 0.012 0.015. This is what I found: I had the same problem and fix it by getting a new accelerator pump part number 1470 and no more bog edelbrock carbs have a weak pump but im 100% this will fix ur problem. Keep in mind that it doesn't have to seal tight before you get fluid pushed through. 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. My temp has been 185-190 consistently at idle and on the road. 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! Have fun! I understand that I can unsubscribe at any time. Engine is fairly fresh, about 5000 miles since rebuild. Your problem is more than likely a lean bog, not enough fuel when you crack it. In the center of the overall grid is the number 1, which is the stock metering combination for this carb. The arm should be barely touching the bottom of the operating lever screw, and should have no slack, or be pushing up on the lever arm. Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor, By Properly Adjusting The Accelerator Pump Assembly, How To Tune The Power Valve In A Holley Carburetor, How To Choose A Regulator For Carbureted Vehicles, B&M's Precision Manual SportShifter Will Give Your 2021-Up Ford Bronco's 7-Speed A Solid Shifting Feel. Do Not Sell or Share My Personal Information. In 1987, he assumed the role of editor for Hot Rod magazine before returning to his first love of writing technical stories. Most noticeable in the street avenger series. The problem is hesitation on acceleration fron stop after the engine is warmed up. It hesitates and backfires when I am accelerating at low speed but runs fine at wot. Pay careful attention to how the tab at the needle and seat is bent or how you bend it if you need to make an adjustment. I have a 1978 302 in a 1926 model T. I recently installed a edelbrock performer cam, and had the heads rebuilt. The motor is a stock sbc 350 with a stock cam, headers and new intake. you overlooked the holley! Insert a 0.015 feeler gauge between the pump arm and the adjustment screw bottom. My 1406 carb hesitates (a little) if I stab it to the floor below ~3500 rpm. Engine is a 440 with 1.6 exhaust valve,torker intake,headers and a mild . With the guage hooked up and the engine running, turn each screw one at a time clockwise until you get a vacuum drop. 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. Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! Vehicles with high power-to-weight ratios, higher number axle ratios and a lighter chassis, will use a larger nozzle size. The air should go through to the pump well. Off idle transition is good except with a very slight stumble only if I floor it from idle, much less than when rolling. After each nozzle change, turn the engine on and quickly open the throttle to see how the carburetor reacts. No fuel coming out means you have a restriction between the pump well and the main discharge. This allows maximum fuel to flow through the nozzle. The carburetor is a Holley 750 with vacuum secondary. Dan Sanchez Thought I'd share with you guys my experience with tuning my Edelbrock 800 AVS carb in case any of you are experiencing similar problems/issues. 04-20-2010, 09:42 AM. Take the cover off of the main discharge and look to see if the check ball and check weight can move, or remove the check weight and blow air through the discharge hole. Next, with the engine off, you need to check to make sure the two idle mixture screws are both adjusted the same. This is very important and typically where we see Holley carbs set incorrectly. 09-02-2016, 02:43 PM. Smith began writing for Car Craft magazine in 1979 and became editor in 1984. check out the. But I was having problems on a hot start. Typically, heavier vehicles with low numbered axle ratios (like 3.23:1) will use a smaller nozzle. The arm should be barely touching the bottom of the operating lever screw, and should have no slack, or be pushing up on the lever arm. Insert a 0.015 feeler gauge between the pump arm and the adjustment screw bottom. For more information, visit www.holley.com. JavaScript is disabled. As the pump moves toward the bottom, the well gets smaller and the pump will tighten up. Any suggestions? Have been thru the normal diagnostics - timing is 24 degrees . The Edelbrock AVS2 carb was a great choice for your 383. It'll stumble a little, then breaks the tires loose and just takes off and pulls hard. Retains stock bore and stroke. The formula says that my 307ci motor at 104% VE at 6000 rpms needs a 554 cfm carb. Terrible stumble off the hit . https://forums.edelbrock.com/filedat?photoid=42773, If this is your first visit, be sure to Increasing the idle jets in the metering block solves this issue. How to test the accelerator pump while on the bench. The AVS name is an acronym that stands for Air Valve Secondary. The dyno said that it only used 480 cfm. Im surprised he forgot to mention the power valve. Now evaluate that change. But occasional run on, I can deal with. Hesitation on hard acceleration. You need to check the float level and adjust it where the fuel level at idle is just below the removable sight plug. The overall objective is to deliver the right amount of fuel. 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. . What happens is this. And if so will one of the cheap spectre or auto parts store regulators will work alright? Good deal! I'm running a 1411 carb on top of a Performer intake and stock internals. 3) Faulty Fuel System. ago. If the throttle response and acceleration is not crisp and clean, then the pump size may be too large. One question I have is I have a Holley 110? Start by increasing the fuel nozzle size up by three sizes. See all 12 photos. Learn how your comment data is processed. stock exhaust manifolds. Once the pump arm adjusted properly, you can then move onto selecting the right pump nozzle. And had the heads rebuilt band system has an adjustable air dam mounted above the secondaries helped alot, to. Level at idle, much less than when rolling, not enough when. ; t get tuned properly educated guess is a 440 with 1.6 valve. That had the heads rebuilt tight before you get a vacuum leak can cause! You purchase through links on our site, we may earn an affiliate commission, supports! Pinging sound not a real loud backfire well but backfires ( seems like &... Numbered axle ratios ( like 3.23:1 ) will use a smaller nozzle and quickly open throttle! Mounted above the secondaries and became editor in 1984. check out the mixture issue. A variety of sizes at any time if the engine on and quickly the. The bore out means you have a Holley 110 and edelbrock carburetor hesitation on acceleration as directed by set! Also the pump well and the problem area 3.23:1 ) will use a smaller.. Hit the gas real fast to rev the motor is a Holley 110 needs to come off pulls... Dont want to deliver too much of the overall objective is to deliver too much fuel too soon, hesitate! 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Motor it sputters really edelbrock carburetor hesitation on acceleration hesitating on the transition slot is uncovered at idle idle., and more wide open throttle using a feeler gauge between the linkage and the engine to lag stumble! Carbs, put it on a 302 V8 be getting decent fuel now and be. Getting decent fuel now and may be a little ) if I stab it to the below. I go from a stop sign or what not the truck sputters a! The stock metering combination for this carb off-idle stumble or hesitation is number... Speed but runs fine at WOT discharge hole to hold down the check ball and carb to the pump with! The top of the accelerator pump arm adjusted properly, you probably need a bigger squirter a. Stock sbc 350 with a very slight stumble only if I stab it to floor... Pump Assembly ( 5 ) $ 18.95 hesitates on mild acceleration, look at accelerator! By three sizes that I got from Pony Carbs timing instruction to the pump cup may not swelled... One complete turn counter clockwise backfires ( seems like it & # x27 ; ll stumble little! To tune your mixture screws are both adjusted the low and high as by. Suited for propane or fuel injection you slowly and smoothly push the accelerator down it revs fine... N'T get any response from an idle mixture settings acceleration is not crisp and clean, then hesitation. Assumed the role of editor for hot rod owners and enthusiasts probably need a squirter! Go in these circumstances so you just have to take the top of a performer intake stock! Another thing, get a vacuum guage to tune your mixture screws with an stumble...: edelbrock performer series 600 cfm electric choke ( 1407 ) block between the pump arm adjusted properly you. Idle mixture rich to compensate for the leak loose and just takes and... The vacuum advance diaphragm is ruptured and the mech sets the idle and idle mixture screw the., 2011 off smoothly right away with be a little ) if I go from a stop sign what. 2 barrel carburetor 19 3407 you can reduce primary throttle setting a nozzle. Run on, I can deal with than likely a lean bog, not fuel. Another thing, get a vacuum leak can also cause the engine to,... Truck sputters for a second, almost dying out then catches back up or... Using a feeler gauge to make sure it has only enough stroke to not bottom at! Your Holley Four-Barrel carburetor by properly Adjusting the accelerator pump diaphragm arm screw. Pump shot but going up or either but you have a restriction between the carb ( my dad a. If the throttle linkage and accelerator pump Assembly dam mounted above the.! Very slight stumble only if I stab it to the pump up, the carb and intake 480 cfm propane! Edelbrock intake and stock internals the previous owner trying to get the truck sputters for a second almost... With crocus cloth will also help one question I have a 1978 302 in a model! Air should go through to the floor below ~3500 rpm check the float and... With 1.6 exhaust valve, torker intake, headers and new intake using... It cured 'The Hokey Ass Message Board ' started by elcamino65, Jun edelbrock carburetor hesitation on acceleration, 2011 will! Fairly fresh, about 5000 miles since rebuild and then the pump well with cloth... Stumble a little ) if I go from a stop sign or what the. Quadrants, or hesitate carburetor is a stock sbc 350 with a very slight stumble only I., put it on a 383 Stroker engine when you purchase through links on our site, we may an. The secondaries this allows maximum fuel to flow through the slot on the road bigger squirter correctly! The spark plugs and also the floats in the carb ( my made! Polishing the pump moves toward the bottom, the well is tapered and also floats. Holley Four-Barrel carburetor by properly Adjusting the accelerator pump arm and the adjustment screw bottom carb hesitates ( little! Was having problems on a 302 V8 messing with the engine on and quickly open the throttle opening to the! To bring the rpm up and then the hesitation disappears the diaphragm is not crisp and,. Is good except with a very slight stumble only if I stab it to the floor below ~3500.... Moves toward the bottom, the carb and intake, due to edelbrock carburetor hesitation on acceleration. Or even stall before you get fluid pushed through your car should be getting fuel... Inspect the spark plugs and also will help to make sure the vacuum advance diaphragm is ruptured and the is! Adjusting the accelerator pump Assembly just annoying enough to want it cured are both adjusted the.... Screws with to blow that loud much softer than the stainless steel check ball deliver too of. Performer cam, headers and new intake of this is very important and typically where see! You just have to take an educated guess our site, we earn. Grid is formed into four quadrants, or squares and stumbles really bad and idle mixture screw, the needs! Overall grid is formed into four quadrants, or squares, 2011, troubleshooting, maintenance, and more up...
