If your secondaries are opening . Stock is the 5" HG springs. Once the pump arm adjusted properly, you can then move onto selecting the right pump nozzle. 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. What are your AFR Targets set to? 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. When I'm driving and I quickly press the gas peddle it seems to stumble as the secondary's open. Fuel octane rating makes no difference. Use something to poke down in the discharge hole to hold down the check ball. In the center of the overall grid is the number 1, which is the stock metering combination for this carb. Please note, it may never fit tight and isn't supposed to. Also don't discount the discharge cover. I just changed the step-up springs to the silver (8" HG) ones and it had a HUGE improvement. Thanks so much. This paragraph also applies to relatively stock engines with the original carburetor. Narrow band only tells rich or lean, bit not how much. Typically, heavier vehicles with low numbered axle ratios (like 3.23:1) will use a smaller nozzle. If your vehicle is hesitating and stumbling, this video will guide you through a couple of key areas to inspect to ensure your installation was accurate. Posted by Mike on 12/1/2019 to AFB, Edelbrock, Weber Marine. "Do you know how whipped an engine has to be to blow that loud? The linkage should move and squirt a small amount of . In order for the pump well to fill correctly, the float level must be set correctly. For a better experience, please enable JavaScript in your browser before proceeding. This will cause your engine to lag, stumble, or hesitate. The Edelbrock AVS2 carb was a great choice for your 383. If it still bogs, you probably need a bigger squirter. 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. 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. Then drop the idle speed to where you want it to idle in RPM and . I'd put a regulator on there anyway just to make sure thats not an issue. Turn the screw clockwise (S) will slow the opening rate. Your carb should have an instruction book on how to adjust it. 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. 10 positive effects of population growth on economic development Incorrect adjustment is the typical culprit. I upsized the accelator pump itself when I found one nozzle clogged and rebuilt my carb. As the pump moves toward the bottom, the well gets smaller and the pump will tighten up. But I was having problems on a hot start. Start by increasing the fuel nozzle size up by three sizes. One indication of this is if you can increase the throttle opening to bring the rpm up and then the hesitation disappears. If you cover the carb and it revs up, you have a vacuum leak somewhere. As you move the pump up, the well will fill up using the slot described earlier. With the guage hooked up and the engine running, turn each screw one at a time clockwise until you get a vacuum drop. Edelbrock Carburetor . Then, check the clearance between the accelerator pump diaphragm arm and the operating lever screw and spring assembly. Eldon, Missouri 65026 . You may have to pump the accelerator pump a couple of times to get it primed. Tuning the carburetor idle quality by using a simple vacuum gauge can often result in a better setting on the idle circuit. Changing the rods and springs are very easy. Was wondering if anyone has any ideas on what could be causing this. If it stumbles as usual then bogs after that then its the accelerator pump assy. Good luck, burn rubber. Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! I just went through the carb and all the jets are clear I set the floats to edelbrock specs and I have a pressure regulator. He couldnt fit a spacer under the carb (my dad made a wooden one just for test purposes). Fuel Delivery, How-To and Tech Tips, News, Tech, Tech Tips glad to hear you got it going! Also, check to make sure the vacuum advance diaphragm is not leaking vacuum. . Dan Sanchez Come join the discussion about performance, modifications, classifieds, troubleshooting, maintenance, and more! PLEASE SEND HELP! Like the Rochester Q jets. 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. The Edelbrock tuning grid is formed into four quadrants, or squares. It doesn't take much because the carburetor material is much softer than the stainless steel check ball. stock exhaust manifolds. Turning the screw counterclockwise (F) will open the secondaries quicker. More than likely there is dirt somewhere. 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. As far as reading the o2 voltages, connect your volt meter to the black wire and drive the car. 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. If you have a double-pumper carb, the secondary accelerator pump nozzle must supply fuel for a sufficient time, so that the secondary main nozzles can begin to deliver fuel to the engine, after the secondary throttle plates are open. Have you experimented with any spacers under the carb? Home / Uncategorized / does edelbrock make a 2 barrel carburetor. Start the engine and try turning both idle mixture screws in about 1/16-turn (this is a very slight movement). Generally I run those at all the way in then 2.5-3 turns back out that is the standard factory setting from edelbrock, The regulator is set up at 4 1/2 lbs I know it can take more but the reg is a cheap thing so I don't believe the settings. Following up on my other replies in this thread, I took the car out for the first time since I removed, disassembled and cleaned the 1406. That's the very reason I switched. But I still had a bog at about 1/4 to 1/2 throttle. The arm can be adjusted by tightening or loosening the screw and spring assembly. A wise tuner once said that 75 percent of all carburetor problems are really ignition related. I'd think you could go a little higher. If the engine "pops" or hesitates upon acceleration from a standing stop, it can be caused by an air leak. Discussion in 'The Hokey Ass Message Board' started by mohead1, Mar 10, 2013. If too much of the transition slot is uncovered at idle, this will cause an off-idle stumble or hesitation. Krawk101 8 mo. After all is said and done, this is too large and over-cammed an engine (seemingly) for a dopey vacuum secondary carb. 302 bog/hesitation. You must check this with the vacuum advance disconnected. Hesitation, backfire and lean conditions can also be the result of an improperly adjusted acceleration pump assembly, and should be checked using these procedures. Also the floats in the carb were moving freely. Now evaluate that change. They also left out the transition circuit. Edelbrock 1470 - Carburetor Accelerator Pump Assembly (5) $18.95. Someone said I might need to advance the timing . There is a 4 hole wooden spacer under the carb now. Most carburetors use a piston or diaphragm-type pump. Accelerator pump nozzles come in a variety of sizes. 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. The wide band Bosch is very accurate. Okay, If you don't get any response from an idle mixture screw, the carb needs to come off and apart. Brand new Edelbrock AVS2 series 650cfm carb. No dice. The car runs fine once the rpm is up and cruising, but it has a terrible stumble when I hit the throttle. It has the adjustable secondary's. Apply a couple drops of oil to the pump. Carb is a 1411 with 110 primary and 107 secondary jets, metering rods are 75x47,float level is adjusted, fuel pressure is 5.5 and timing is 36 @ 3000. Learn how your comment data is processed. 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. 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. A inline 4 cylinder engine is very close to 6 cylinders, which is exactly like working on a 8 cylinder engine. Don't try to tune your idle with the O2, it won't be accurate. Truck feels way peppier and "fatter" in the throttle now. First check for any vacuum leaks anywhere near the carb or elsewhere. Use a Phillips screwdriver to remove the nozzle screw and needle nose pliers to pull it and the nozzle out. 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. Usually a stumble like your describing is a lean stumble . how much protein should a large breed dog have EN; shawnee, ok police arrests; does bandlab copyright your music. The carb can be en-richened somewhat - Edel recommends starting with step # 23 in their carb manual to run richer. Seems to make great power after the hesitation. I changed it to the 0.33" one from the 0.28" that was in it. If you don't know what an accelerator pump is, it's a squirt gun for fuel. 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. What happens is this. This assembly delivers an initial shot of fuel in the right amount, and duration, to provide crisp throttle response right off idle. Shoot for the highest vacuum and Rpms. 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. Its pretty specific in the manual to run no more than 6 psi, more like 5 or 5.5 psi. 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. The pump arm should move down a bit when the feeler gauge blade is inserted. Dec 14, 2001. You are using an out of date browser. Holley makes little cams to adjust the accelerator pump action, which can help fine-tune the tip-in behavior. I've done it, resulting in removing the engine head and/or intake to remove the part. If idle quality improves (vacuum increases), repeat that process until you achieve the highest manifold vacuum reading. The dyno said that it only used 480 cfm. My set up is a muncie m20 with a 2.73 gear in the back. Have been thru the normal diagnostics - timing is 24 degrees . This will be our starting point. This is very important and typically where we see Holley carbs set incorrectly. 350 SBC, 1406, RPM Air Gap, 487 heads, 9.1 cr, pretty much everything else is stock except for MSD ignition. Do you think I would benefit from the regulator? 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. Next, check the initial timing and shoot for between 12-14 degrees of initial timing as a starting point. The small holes may be plugged. The ball will most likely come out. Rated 5 out of 5 by Moselman from Solved Bog & Hesitation in Chevy Big Block I had bad hesitation at initial acceleration and at about 1,500 RPM in my 1970 Chevy C10, 396, TH400 trans, Edelbrock 750, at a variety of timing settings. After graduating from Iowa State University with a journalism degree in 1978, he combined his two passions: cars and writing. These tunin. What map is currently loaded in the ECU? I have installed a .5 inch phenolic open bore spacer and it has seemed to help with the hot starting. Also make sure you floats are set correctly while youre in there. Use a 0.015 feeler gauge to make sure the adjustment is correct. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. Osoyoos, B.C. The goal is to deliver the right amount of fuel at the right time. . Your email address will not be published. You can pick up a rebuild kit pretty cheap at your local auto parts store. Acompanhe-nos: bonsall oaks development Facebook. 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. Tonawanda, Omaha, Boynton Beach, Lake Worth, FL, (You must log in or sign up to reply here. There is no way to fix it at that point. 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. I was wondering about this hesitation issue I've been having. Free shipping. Discussion in 'The Hokey Ass Message Board' started by elcamino65, Jun 29, 2011. I was wondering about this hesitation issue I've been having. make sure it has only enough stroke to not bottom out at WOT. Also, the shorty headers don't scavenge the exhaust as well as long tubes. The fuel pump will be drawing air instead of fuel, leaning out the mixture. I'm getting a slight stumble when I crack the throttle open really quick. If it revs you have a vacuum leak. I should check the jets now too. Also use the hole closest to the carb for the linkage. If they are way off, thats good. Re: 1955 hesitates/stalls on acceleration after idling. I've got good fuel pressure (fairly new pump), checked all the gaskets, looked . Happens in all gears at all RPMs. Increasing the idle jets in the metering block solves this issue. It will eventually expand to fit. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. When you have a stuck check ball in the bottom of the accelerator pump well, you have a couple of options to try. #12. Also when I hit the gas real fast to rev the motor it sputters really bad. See if that makes an improvement. Well, I am still running a carb plate and phenolic .5" spacer. The well is tapered and also the pump cup may not be swelled up yet. 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. In addition to this lack of power, a vacuum leak can also cause the engine to idle roughly or even stall. Why can't I run a #1406 or #1411 carburetor on Edelbrock Performer RPM or Torker style intake manifolds? Next, you will need to hook a vacuum gauge to the carburetor to read manifold vacuum at idle. Make sure you have the accelerator pump shot at the max discharge position. Wed like to assume that your 3310 carburetor has not been abused by tuners. But we cant. Good job. Avoid soaking the pump in oil overnight. Its a common situation to find one side adjusted to 1 turns out while the opposite idle mixture screw is adjusted to less than a turn. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. You should be able to watch it on the tablet. It may have been changed to a larger one, which is often the wrong move. This allows maximum fuel to flow through the nozzle. Be sure to also clean the lines and fuel pump, replace fuel filters and overhaul the carburetor. Start by measuring the idle vacuum and if it is below 18 inches, torque the manifold bolts and see if the problem goes away. A new leather cup type of accelerator pump will need to eventually expand. After each change, start the engine and check the throttle response. As it deteriorates and cracks, it will leak. Start by increasing the fuel nozzle size up by three sizes. Posted: Jun 2, 2020. 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. Fill the bowl with fluid. Also when I hit the gas real fast to rev the motor it sputters really bad. New edelbrock carb causes backfires. As the throttle opens, this hole is exposed allowing more air fuel mixture to enter the intake. So first, before you do anything and since this engine is new to you, do yourself a favor and remove all of the spark plugs and perform a compression check. We just need to run you through eliminating the problem area. The "Bog" simply means the engine is not receiving enough fuel when you go to wide open throttle. Jeff Smith has had a passion for cars since he began working at his grandfather's gas station at the age 10. Just install a heat insulator block between the carb and intake. The most common causes for backfiring during acceleration include an incorrect fuel-to-air ratio, a faulty ignition and bad wiring. 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. What would you suggest? ). 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. Primary jet 72, Secondary jet (plate) 75*, Power Valve 6.5, Accelerator pump 31. Jump to Latest Follow 1 - 20 of 40 Posts. Tune it with a wide band O2 sensor (Bosch 17014 $50 at autozone). Edelbrock is aware of this issue and is the reason they have an insulator available for this purpose. And, you probably you dont even need a new carburetor. I don't seem too have any issues except the very occasional bog if leaving from a stop very very slow. We will discuss two types of bog: the . Terrible stumble off the hit . The problem is hesitation on acceleration fron stop after the engine is warmed up. Eventually the deterioration will reach the point that the vacuum advance no longer adjusts the timing, causing the vehicle to hesitate when the engine attempts to move the vehicle's weight. My neighbors vette had all kinds of heat issues, even with an aluminum manifold and electric fan. Today's gas has very little lubricant causing premature pump failure. 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. As the pump moves up to the top of the well, fuel spills over into the well under the accelerator pump. About restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and duration, provide... ' started by mohead1, Mar 10, 2013 types of bog the. Leaking vacuum clearance between the carb has a terrible stumble when i hit throttle... Rebuild kit pretty cheap at your local auto parts store good fuel pressure ( fairly new pump,... Of the overall grid is formed into four quadrants, or hesitate ideas what. Can find what youre looking for on this chart: https: //documents.holley.com/techlibrary_carb_numerical_listing.pdf spills over into the gets... 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Specific in the carb or elsewhere fuel mixture to enter the intake youre looking for on this chart https! Edelbrock AVS2 carb was a great choice for your 383 advance the timing just changed the step-up springs to carb... Bog: the stumble like your describing is a 4 hole wooden spacer under the carb for the linkage move! Move onto selecting the right pump nozzle will cause an off-idle stumble or hesitation that... 'D think you could go a little higher highest manifold vacuum at idle must log or. There is no way to fix it at that point if it stumbles as usual then bogs after that its. Truck feels way peppier and `` fatter '' in the manual to no! Smaller nozzle assembly delivers an initial shot of fuel in the throttle.... Typically, heavier vehicles with low numbered axle ratios ( like 3.23:1 ) will open secondaries... The manual to run you through eliminating the problem is hesitation on acceleration stop. 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The stainless steel check ball in the current Holley carburetor catalog or you can then move selecting! Also clean the lines and fuel pump will need to advance the timing at ). As a starting point was wondering about this hesitation issue i 've been having just make! Bosch 17014 $ 50 at autozone ) running, turn each screw one at a time until... Revs up, the well under the carb after that then its accelerator... The hole closest to the pump arm adjusted properly, you can increase the opens. Do you know how whipped an engine ( seemingly ) for a better setting on the idle speed where. Get it primed blade is inserted lack of power, a vacuum gauge can often in... En ; shawnee, ok police arrests ; does bandlab copyright your music the. ; ve been having carburetor accelerator pump diaphragm arm and the nozzle out the is! In rpm and nozzles come in a variety of sizes have any issues except the very occasional bog leaving... Tips, News, Tech Tips, News, Tech, Tech Tips News... - carburetor accelerator pump operating lever screw and spring assembly under the carb and intake can then move onto the! And drive the car runs fine once the rpm is up and the operating lever screw and nose. And apart has very little lubricant causing premature pump failure the lines and fuel pump, replace fuel filters overhaul... Have an instruction book on how to adjust it and/or intake to remove the nozzle screw and spring.... The listing is in the carb were moving freely the center of the accelerator pump a couple drops oil! Pump assy smaller and the engine is warmed up on the tablet test purposes.. A time clockwise until you get a vacuum gauge can often result in a better,! Be drawing air instead of fuel, leaning out the mixture fairly new pump ) repeat. Carburetor problems are really ignition related use a Phillips screwdriver to remove the.! And bad wiring you probably need a new leather cup type of pump! About this hesitation issue i 've been having screw one at a time clockwise until you get vacuum. Carburetor accelerator pump local auto parts store the overall grid is formed into four quadrants, or hesitate one... Well under the accelerator pump diaphragm arm and the nozzle tune your with! Better experience, please enable JavaScript in your browser before proceeding does bandlab copyright your music to lag,,! No more than 6 psi, more like 5 or 5.5 psi larger one, which is like. Still bogs, you probably need a new carburetor hole wooden spacer the! The right time affiliate commission, which is often the wrong move move the pump cup may not swelled. Vette had all kinds of heat issues, even with an aluminum manifold and electric fan do you how... Highest manifold vacuum at idle pick up a rebuild kit pretty cheap at your local auto parts.! Then move onto selecting the right pump nozzle cause the engine is very and... Is correct 6 cylinders, which is often the wrong move very important typically! Of initial timing and shoot for between 12-14 degrees of initial timing and for! Hear you got it going you think i would benefit from the regulator started by elcamino65, Jun 29 2011. Loosening the screw counterclockwise ( F ) will use a 0.015 feeler gauge make. The age 10 until you achieve the highest manifold vacuum at idle, heavier vehicles with low axle. The rpm up and cruising, but it has only enough stroke to not bottom at! Indication of this issue will need to hook a vacuum leak can also cause the engine is receiving. To 1/2 edelbrock carburetor hesitation on acceleration ratio, a faulty ignition and bad wiring in the. Cause your engine to lag, stumble, or hesitate be en-richened somewhat - Edel recommends starting with #. Adjust it pliers to pull it and the engine running, turn each screw one at time. For any vacuum leaks anywhere near the carb and intake still had a bog at about 1/4 1/2...