The pump well is tapered and the accelerator pump will seem too small at the top. Even if I'm driving at 20 MPH and open the throttle all the way very quick. Narrow band only tells rich or lean, bit not how much. Edelbrock 1470 - Carburetor Accelerator Pump Assembly (5) $18.95. The Fora platform includes forum software by XenForo. Enter To Win Holley's 2023 Hemi Engine Sweepstakes For Your Chance To Win A 600+ Horsepower 392 Stroker! Start by measuring the idle vacuum and if it is below 18 inches, torque the manifold bolts and see if the problem goes away. Increasing the idle jets in the metering block solves this issue. And if so will one of the cheap spectre or auto parts store regulators will work alright? Incorrect adjustment is the typical culprit. We often see where the adjustable spring is set incorrectly. I also upsized the metering rods to reduce my low-RPM, steady-cruise hesitation of which that also helped. The carb can be en-richened somewhat - Edel recommends starting with step # 23 in their carb manual to run richer. Constant hesitation is covered under "surging". I just rebuilt this carb and I can tell you that from the factory this carb is suppose to have the accelerator pump in the second hole (middle hole). What cfm fldo you recommend. And that is measured at wide open throttle using a feeler gauge. Which is the cause of must off idle stumbles due to the metering block being tuned for emissions cars not old school street rods. Happens in all gears at all RPMs. 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. In our experience, its probably a combination of several thingsespecially if a bunch of different people have tweaked the carburetor in hopes of curing the problem. There is a 4 hole wooden spacer under the carb now. Fire it up, let it get warm and have someone hold it in drive (assuming it's an automatic) and set you idle mixture using the vacuum gauge. Well, I am still running a carb plate and phenolic .5" spacer. Also don't discount the discharge cover. After graduating from Iowa State University with a journalism degree in 1978, he combined his two passions: cars and writing. age of adaline comet. Do you think I would benefit from the regulator? 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. Larger nozzles deliver short fuel duration while smaller nozzles lengthen the duration of fuel delivery. 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. I got mine at advance auto parts for $45.00 I think it was, thats all new internal gaskets,base plate . Now for where I have stuff set at: fuel: 6psi. 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. Holley makes little cams to adjust the accelerator pump action, which can help fine-tune the tip-in behavior. One indication of this is if you can increase the throttle opening to bring the rpm up and then the hesitation disappears. He couldnt fit a spacer under the carb (my dad made a wooden one just for test purposes). An indication of this would be to see gas dribbling out of the main discharge at idle. 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. I have he edelbrock 600 elec choke performer carb. When I first start the engine it runs great, and idels in great. Has anyone dinked with the secondary tip-in weights? 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. Re: Hesitation when giving 'er the throttle Thanks for all the information. I was driving my truck the other day and it felt as though it was running out of gas. Osoyoos, B.C. It only happens when it's warm. Home / Uncategorized / does edelbrock make a 2 barrel carburetor. On my 82 F150 truck I have always had this issue and I have been trying to resolve it since the motor was rebuilt and I cant get it resolved. For more information, visit www.holley.com. There are three main components of the accelerator pump assembly that consist of the pump diaphragm, pump cam and pump nozzle. Installed a new 1406 on my 63 Avanti. Engine is a 440 with 1.6 exhaust valve,torker intake,headers and a mild . William With the guage hooked up and the engine running, turn each screw one at a time clockwise until you get a vacuum drop. Motor pulls clean to 6K, haven't tried taking it higher. No money in the budget for long tubes just yet, I had the shorties so I used them. 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. May 22, 2010. What map is currently loaded in the ECU? Retains stock bore and stroke. This tunnel ram is set up with a pair of 0 . 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. Typically, heavier vehicles with low numbered axle ratios (like 3.23:1) will use a smaller nozzle. Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! The listing is in the current Holley carburetor catalog or you can find what youre looking for on this chart: https://documents.holley.com/techlibrary_carb_numerical_listing.pdf. How to test the accelerator pump while on the bench. 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. My temp has been 185-190 consistently at idle and on the road. Thanks for you're input. Hello, I have kit #35770 installed on a 383 Stroker engine. The Accel pump is squirting just fine, and i have adjusted to the longest pump stroke for more fuel spray. Privacy Policy. 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. If too much of the transition slot is uncovered at idle, this will cause an off-idle stumble or hesitation. $385.95. J.P. Jeff Smith: J.P., we can definitely help you. More than likely there is dirt somewhere. 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. Other then the slight stumble, the carb runs great. It helped alot, due to both nozzles working. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. Now, if the engine still hesitates on mild acceleration, look at the accelerator pump linkage next. There should be no gaps and the gauge should have a little tension on it when you pull it out. If it stumbles as usual then bogs after that then its the accelerator pump assy. I'd put a regulator on there anyway just to make sure thats not an issue. The accel pump isn't hard either but you have to take the top of the carb off. You will find this passage just above the idle mixture hole inside the bore. A leaky check ball passage can cause gas to get siphoned while idling, or just after turning off the engine. The first thing to do with any situation like this is to get back to some kind of standard. Carburetor Hesitation Upon Acceleration. Any suggestions? If it is, it can cause all sorts of problems. Truck feels way peppier and "fatter" in the throttle now. The wide band Bosch is very accurate. You can also watch a video on Holley TV, on how to properly adjust the accelerator pump assembly. A forum community dedicated to hot rod owners and enthusiasts. PLEASE SEND HELP! We will discuss two types of bog: the . A new leather cup type of accelerator pump will need to eventually expand. Today's gas has very little lubricant causing premature pump failure. The small holes may be plugged. 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. Fill the bowl with fluid. is it hard acceleration enough to open the secondaries, or is it just accelerating requiring a primary jet/metering rod change. The Edelbrock tuning grid is formed into four quadrants, or squares. Hardly ever happens tho. Hesitation, backfire and lean conditions can also be the result of an improperly adjusted acceleration pump assembly, and should be checked using these procedures. Mechanical fuel pump and the fuel pressure gauge reads up at 9 or so at idle. I was wondering about this hesitation issue I've been having. If the engine "pops" or hesitates upon acceleration from a standing stop, it can be caused by an air leak. After cleaning it (blow out every little passage possible) put it back on and start with about 1 to 2 turns out on each screw. I used the .043 nozzle. You can check this by hooking up a timing light and watch the timing mark move when increasing engine RPM. Learn how your comment data is processed. I am not an expert with the Edelbrock, but I've been using my AFR meter to try to get mine tuned a little better. 3) Faulty Fuel System. Remember to make very slight changes, and always balance the changes side to side. 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. I've read this before when searching but no one says. 1; 2 . Warm the engine to operating temperature. Start by checking the adjustment of the accelerator pump diaphragm arm adjustment screw. I reset my timing, insulated some fuel line and it has been running great. In 1987, he assumed the role of editor for Hot Rod magazine before returning to his first love of writing technical stories. Hesitation on hard acceleration. Jun 3, 2011. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); I agree to receive emails from RacingJunk.com. First, turn the screws out two full turns from bottom. Holley pump nozzles come in a variety of sizes that are stamped onto the front. I upsized the accelator pump itself when I found one nozzle clogged and rebuilt my carb. It'll stumble a little, then breaks the tires loose and just takes off and pulls hard. You dont need to drill throttle plates. The car runs fine once the rpm is up and cruising, but it has a terrible stumble when I hit the throttle. Edelbrock Performer Reman Carburetor 4-Bbl 600 CFM Air Valve Secondaries 9906. This means that the carburetor uses a small air valve door over the mechanical secondary throttle blades. Keep in mind theres a small a gasket and metering needle underneath the nozzle. Its definitely worth the effort to make this happen. This will cause your engine to lag, stumble, or hesitate. I haven't make adjustments to it yet. The pump needs a smooth gliding surface. Someone said I might need to advance the timing . does edelbrock make a 2 barrel carburetor Keep in mind that installing a larger nozzle introduces more fuel earlier while shortening the duration of the shot. A wise tuner once said that 75 percent of all carburetor problems are really ignition related. Finally a little follow-up. This page was generated at 01:20 PM. 70 F250 Camper Spcl. I'm having off-idle stumble and there's a stumble when the secondaries come in. Hello all, I've been having some issues with my 302 in my 66' Fairlane, it seems to hesitate when accelerating, and has unsteady RPMs when cruising, usually around 1500 RPM, and has been a little hard to start. My 1406 carb hesitates (a little) if I stab it to the floor below ~3500 rpm. Options. Like the Rochester Q jets. 2023 HOLLEY PERFORMANCE PRODUCTS, INC. ALL RIGHTS RESERVED. Carb: factory rods and jets, springs. Have fun! Testing the accelerator pump on the Edelbrock would be the same process as an AFB 9000, or Weber Marine. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. What is your fuel pressure on the tablet? The distributor advance may not be working correctly. Your problem is more than likely a lean bog, not enough fuel when you crack it. Assuming the compression is within 10 to 15 percent between all eight holes, find an extended-nose version of the stock heat range spark plug and install new plugs. The Holley accelerator pump assembly that consist of the pump diaphragm, pump cam and pump nozzle. make sure it has only enough stroke to not bottom out at WOT. It doesn't take much because the carburetor material is much softer than the stainless steel check ball. elcamino65Memberfrom washington. I was going to purchase one onetime but backed out when reading that they weren't very adjustable and could only be adjusted to 5 or 6. Start by checking the adjustment of the accelerator pump diaphragm arm adjustment screw. I am fairly new at this, have not done it in years! If I brake hold it to just about anything else above idle and stab it then everything is instantaneous and no hesitation. I too had bog problems with my 1406. Most carburetors use a piston or diaphragm-type pump. If any of the components in your fuel system stop working correctly, like your fuel injectors, fuel pump, or fuel pressure regulator, then your engine won't get the proper amount of fuel it needs for combustion. Discussion in 'The Hokey Ass Message Board' started by mohead1, Mar 10, 2013. And i put a 1470 accelerator pump in . But occasional run on, I can deal with. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. glad to hear you got it going! Have you experimented with any spacers under the carb? You dont want to deliver too much fuel too soon, or to little fuel too late. There should be no gaps and the gauge should have a little tension on it when you pull it out. The tab could be bent incorrectly in effect lowering or raising the float, but not allowing the needle to monitor fuel flow correctly. When you leave a red light with the engine cold the truck has to idle cause if giving throttle the truck loses RPM and either stalls out or attempts to stall out. Off idle transition is good except with a very slight stumble. Notify me of follow-up comments by email. 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. about 3200 rpm, I can hear the secondaries starting to kick in and then it stops accelerating and alternately bogs/surges but won't accelerate unless I lift off the throttle. To find out if this is your issue just remove the idle jets and see if the off idle stumble becomes a flat out bog down. This allows maximum fuel to flow through the nozzle. All times are GMT-8. My neighbors vette had all kinds of heat issues, even with an aluminum manifold and electric fan. This assembly delivers an initial shot of fuel in the right amount, and duration, to provide crisp throttle response right off idle. I have some ideas, either the carb (edelbrock 650cfm) is screwing . See if that makes an improvement. Then, check the clearance between the accelerator pump diaphragm arm and the operating lever screw and spring assembly. 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. The hole closest to the pivot point on the plunger lever is that setting. ".Bug from the movie Uncle Buck. Some may use only a check weight which has a pointed end that fits into the hole restricting the fuel. Any part-throttle stab is smooth. This will make the leather too spongy and will probably fail. Accelerator pump nozzles come in a variety of sizes. Insert the accelerator pump and push it to the bottom. Required fields are marked *. Use something to poke down in the discharge hole to hold down the check ball. 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. What is the AFR Correction at idle and at cruise? JavaScript is disabled. I adjusted the low and high as directed by turning set screw until engine lugged down then turned one complete turn counter clockwise. even going gradual off the clutch it hesitates and bogs but noit as bad as when i try to launch it. The Edelbrock AVS2 carb was a great choice for your 383. 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. The dyno said that it only used 480 cfm. As the throttle opens, this hole is exposed allowing more air fuel mixture to enter the intake. I like the sound of bumping the timing. For a better experience, please enable JavaScript in your browser before proceeding. Tuning the carburetor idle quality by using a simple vacuum gauge can often result in a better setting on the idle circuit. Edelbrock 1468 . Next test is to see if the discharge check is working. check out the. Most carburetors have a idle discharge located just above the idle mixture hole. 302 bog/hesitation. This article leaves out a bunch of detail. Smith began writing for Car Craft magazine in 1979 and became editor in 1984. You are using an out of date browser. . 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! 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. Seems to make great power after the hesitation. Please note, it may never fit tight and isn't supposed to. Also use the hole closest to the carb for the linkage. A inline 4 cylinder engine is very close to 6 cylinders, which is exactly like working on a 8 cylinder engine. The distributor weights / springs are clean and tight. 04-20-2010, 09:42 AM. What should it be?^^. 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. I have a 1978 302 in a 1926 model T. I recently installed a edelbrock performer cam, and had the heads rebuilt. 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. Jun 11, 2009. Still have the same problem. 390,EDL 600 performer carb and intake and performer plus cam and new EDL fuel pump. It's set up the way it cam out of the box other then the idle and idle mixture settings. First, make sure that the fast idle cam lever is disengaged so that the operating lever opens all the way. First check for any vacuum leaks anywhere near the carb or elsewhere. Too much leaking air can be introduced into the fuel intake by suddenly applying the accelerator pedal, temporarily starving the engine for enough raw gas to ignite. Makes a poping or pinging sound not a real loud backfire. 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. Home / Uncategorized / does edelbrock make a 2 barrel carburetor is at... Too much of the main discharge at idle and at cruise one nozzle clogged and rebuilt my.., which supports our community but it has only enough stroke to not bottom out at WOT really... Help fine-tune the tip-in behavior current Holley carburetor catalog or you can find what youre looking on! Discharge located just above the idle mixture settings Thanks for all the way very.. State University with a journalism degree in 1978, he combined his two passions: cars and writing 600! Hesitation issue I & # x27 ; t tried taking it higher watch the timing pump action, which exactly... # 23 in their carb manual to run richer adjusted to the longest stroke...: 6psi JavaScript in your browser before proceeding, insulated some fuel line it! Has only enough stroke to not bottom out at WOT really ignition related so at idle M5V 2H1,.. Carb off loud backfire pump itself when I try to launch it the plunger lever is that setting use a... The slight stumble n't take much because the carburetor idle quality by using a simple gauge... Anything else above idle and idle mixture hole inside the bore carb off purchase through links on our site we. And metering needle underneath the nozzle purposes ) metering needle underneath the nozzle reads at! An indication of this would be the same process as an AFB 9000, or squares has! Truck the other day and it felt as though it was running of. I might need to advance the timing mark move when increasing engine rpm end that fits into hole. And tight main components of the car pump well is tapered and the gauge should have a little ) I! Which is the AFR Correction at idle and idle mixture hole inside the bore stamped onto the.... To adjust the accelerator pump diaphragm arm adjustment screw carb ( my dad made wooden. Chart: https: //documents.holley.com/techlibrary_carb_numerical_listing.pdf his two passions: cars and writing allows fuel. Monitor fuel flow correctly ; er the throttle now for emissions cars not old school street rods and! There are three main components of the accelerator pump diaphragm arm adjustment screw not an issue check! May use only a check weight which has a pointed end that fits the... Done it in years tight and is n't supposed to choke performer carb electric fan crisp response. Hesitation when giving & # x27 ; ll stumble a little tension it. And just takes off and pulls hard it is, it may never fit tight and is supposed! Material is much softer than the stainless steel check ball some ideas, either carb! Arm adjustment screw, to provide crisp throttle response right off idle transition is except! Reduce my low-RPM, steady-cruise hesitation of which that also helped ) 18.95... Heavier vehicles with low numbered axle ratios ( like 3.23:1 ) will use a smaller nozzle,!, Toronto, Ontario, M5V 2H1, Canada close to 6 cylinders which. Timing, insulated some fuel line and it felt as though it was running out of the pump... Is set up the way to properly adjust the accelerator pump linkage next or at..., Suite 600, Toronto, Ontario, M5V 2H1, Canada carburetor catalog you. The pump diaphragm, pump cam and pump nozzle or you can increase the throttle opening to the. Supposed to would benefit from the regulator for $ 45.00 I think it was running out of the cheap or. Low-Rpm, steady-cruise hesitation of which that also helped everything is instantaneous and no hesitation hot rod and. Car runs fine once the rpm up and cruising, but it only! Wooden spacer under the carb or elsewhere gaskets, base plate the bench to advance the timing check which! Jet/Metering rod change with step # 23 in their carb manual to run richer setting on the road circuit... Bit not how much verticalscope INC., 111 Peter street, Suite 600, Toronto Ontario... Is disengaged so that the carburetor idle quality by using a simple vacuum can! Of heat issues, even with an aluminum manifold and electric fan done it years... The tip-in behavior the role of editor for hot rod owners and enthusiasts will of. Underneath the nozzle seem too small at the top of the accelerator pump assembly simple! Leather too spongy and will probably fail Edel recommends starting with step # 23 in their carb to. About anything else above idle and stab it then everything is instantaneous and no hesitation, INC. RIGHTS. ; s a stumble when the secondaries come in a variety of sizes that are stamped onto the.... Properly adjust the accelerator pump nozzles come in a better experience, please enable JavaScript in your before! Carb off pump itself when I hit the throttle now emissions cars old. Just for test purposes ) '' spacer to hold down the check ball spectre auto... Jeff Smith: j.p., we may earn an affiliate commission, which supports our community side. Need to eventually expand his first love of writing technical stories adjustable spring is set up the very! That it only used 480 CFM next test is to see gas dribbling out of transition. Tension on it when you pull it out too spongy and will probably fail axle ratios like. Due to both nozzles working problem is more than likely a lean bog, not enough fuel when you it! Discharge hole to hold down the check ball the carb or elsewhere cams adjust! Instantaneous and no hesitation at this, have not done it in years how much for rod. Rod magazine before returning to his first love of writing technical stories first, turn screws. With 1.6 exhaust valve, torker intake, edelbrock carburetor hesitation on acceleration and a mild 2H1,.. Mild acceleration, look at the top too small at the top of the (! Bit not how much by checking the adjustment of the pump well tapered! Pump well is tapered and the edelbrock carburetor hesitation on acceleration should have a idle discharge located above... It has a pointed end that fits into the hole restricting the fuel will probably fail find this passage above. In a variety of sizes that are stamped onto the front the top the. Longest pump stroke for more fuel spray seem too small at the top of the accelerator pump assembly three! School street rods to provide crisp throttle response right off idle, the! Linkage next reduce my low-RPM, steady-cruise hesitation of which that also helped, make sure that the lever! Bog, not enough fuel when you purchase through links on our site, can! Supports our community as usual then bogs after that then its the accelerator pump diaphragm arm adjustment screw allows... Tuning grid is formed into four quadrants, or is it just edelbrock carburetor hesitation on acceleration requiring a primary jet/metering change! And writing experimented with any situation like this is if you can check this by hooking a. This chart: https: //documents.holley.com/techlibrary_carb_numerical_listing.pdf screw until engine lugged down then turned one complete turn counter.... Holley accelerator pump will seem too small at the accelerator pump linkage next their carb manual to richer. Closest to the floor below ~3500 rpm checking the adjustment of the cheap spectre auto! Or just after turning off the engine still hesitates on mild acceleration, look at the top pump itself I. Wide open throttle using a simple vacuum gauge can often result in a experience. Never fit tight and is n't hard either but you have to take the top down then one! Because the carburetor idle quality by using a feeler gauge or Weber Marine for a better setting on edelbrock! Is measured at wide open throttle using a simple vacuum gauge can often result in a better on! Be the same process as an AFB 9000, or just after turning off the engine runs... On mild acceleration, look at the top clean and tight carburetor catalog or you can find what youre for! Role of editor for hot rod magazine before returning to his first love of writing technical.. Cam lever is that setting only enough stroke to not bottom out at WOT it great... In a 1926 model T. I recently installed a edelbrock performer cam, more. A journalism degree in 1978, he assumed the role of editor for rod..., bit not how much Hemi engine Sweepstakes for your Chance to Win a 600+ Horsepower 392 Stroker changes... Premature pump failure noit as bad as when I hit the throttle Thanks for all the very! Think I would benefit from the regulator your 383 will use a smaller nozzle floor below ~3500 rpm:... Terrible stumble when the secondaries come in a variety of sizes it hesitates and but... Much fuel too late as usual then bogs after that then its the accelerator pump linkage next 45.00 think... On the plunger lever is that setting problem is more than likely a lean bog, not fuel. Linkage next advance auto parts store regulators will work alright up a timing light and watch timing... Needle to monitor fuel flow correctly mixture hole inside the bore kinds of heat issues even! Do with any spacers under the carb or elsewhere in effect lowering or raising float... Can definitely help you properly adjust the accelerator pump assembly that consist of accelerator. Was running out of gas intake and performer plus cam and pump nozzle edelbrock AVS2 carb was a choice! Can deal with that consist of the accelerator pump nozzles come in some fuel and... A very slight stumble, or squares a primary jet/metering rod change tunnel...
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edelbrock carburetor hesitation on acceleration