Failure to check that or setting that clearance any smaller will result in rupturing the pump diaphragm. Brand new Edelbrock AVS2 series 650cfm carb. Also when I hit the gas real fast to rev the motor it sputters really bad. Then, check the clearance between the accelerator pump diaphragm arm and the operating lever screw and spring assembly. As the pump moves up to the top of the well, fuel spills over into the well under the accelerator pump. Discussion in 'The Hokey Ass Message Board' started by elcamino65, Jun 29, 2011. One question I have is I have a Holley 110? 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. Narrow band only tells rich or lean, bit not how much. bikingplumber. stock exhaust manifolds. The pump well is tapered and the accelerator pump will seem too small at the top. sggoat, ErikinSC and Solace in Solitude. Easy to experiment. I have a 1978 302 in a 1926 model T. I recently installed a edelbrock performer cam, and had the heads rebuilt. 1967 - 1972 F-100 & Larger F-Series Trucks - F100 hesitation stumble when accelerating from stop - i have a 1969 f100 2wd auto 3 speed i think 360 v8 autolite 2100 carb with 1.23 stamped on it main question is -it stumbles when stepping on pedal now from stop before i tried re-adjusting the carb it would spin the. 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. 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. I was wondering about this hesitation issue I've been having. Pulled and flushed the gas tank and fuel lines and replaced the fuel sending unit and in line filters (the sock in the tank and at the carb. You may have to pump the accelerator pump a couple of times to get it primed. I have some ideas, either the carb (edelbrock 650cfm) is screwing . This will let you inspect the spark plugs and also will help to make sure there isnt a bad cylinder. I've tried messing with the accel pump shot but going up or down doesn't really have much effect. Get cruise voltage at .450 Volts and WOT at around .880-.930 volts. 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. 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. In order for the pump well to fill correctly, the float level must be set correctly. The "Bog" simply means the engine is not receiving enough fuel when you go to wide open throttle. No fuel coming out means you have a restriction between the pump well and the main discharge. The motor is a stock sbc 350 with a stock cam, headers and new intake. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); I agree to receive emails from RacingJunk.com. . Terms of Service. I just bought a nice 69 Dodge Charger with a 440 that I got on a really good deal because the previous owner had given up trying to make the engine run correctly. An indication of this would be to see gas dribbling out of the main discharge at idle. Do you think I would benefit from the regulator? Truck feels way peppier and "fatter" in the throttle now. Hesitation on hard acceleration. I have an edelbrock performer intake and 600 cfm performer carb. Weve included a chart that lists all the stock settings for jetting, power valve, and accelerator pump nozzle sizes to help you with making sure these things have not been changed. Im surprised he forgot to mention the power valve. In addition to this lack of power, a vacuum leak can also cause the engine to idle roughly or even stall. Please note, it may never fit tight and isn't supposed to. Next, with the engine off, you need to check to make sure the two idle mixture screws are both adjusted the same. Jump to Latest Follow 1 - 20 of 40 Posts. Turn that distributer counterclockwise a bit and then drive it. Often this 2-inch flexible fuel line at the tank can be the cause of a lot of carburetion issues. First check for any vacuum leaks anywhere near the carb or elsewhere. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. Acompanhe-nos: bonsall oaks development Facebook. Thanks for you're input. If you still have the hesitation, move to the air valve spring force. 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. Just install a heat insulator block between the carb and intake. The AVS name is an acronym that stands for Air Valve Secondary. I like the sound of bumping the timing. 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. ). 2023 HOLLEY PERFORMANCE PRODUCTS, INC. ALL RIGHTS RESERVED. (Image/Holley). posted 09-08-2005 04:44 PM. We use mineral spirits (odorless) for all of our testing. . Changing the rods and springs are very easy. Polishing the pump well with crocus cloth will also help. Set them both the same at about 1 turns counterclockwise from fully seated. 1406 sounds a little small for your mods. Engine is fairly fresh, about 5000 miles since rebuild. 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. The linkage should move and squirt a small amount of fuel with the lightest touch of the linkage. This will help lubricate the well. Each of the four . 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. 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. Holley makes little cams to adjust the accelerator pump action, which can help fine-tune the tip-in behavior. Good luck, burn rubber. I have heard a lot about Edelbrock 1409 for this particular engine and will have to do some further research to see if that is a good choice. Maybe ground on 'em or filed 'em? I am also running the edelbrock air/fuel gauge and also running an aluminum intake. This is an involved process that is too long to discuss here. 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. Making adjustments to the accelerator pump assembly are simple once you understand how the system works. The Edelbrock tuning grid is formed into four quadrants, or squares. I just don't really have any reason to stab it WOT from idle from a dead stop. I should check the jets now too. But I was having problems on a hot start. I've done it, resulting in removing the engine head and/or intake to remove the part. If your rolling into the throttle easily and getting a stumble part way in the problem is in the idle transition circuit . I reset my timing, insulated some fuel line and it has been running great. Dec 14, 2001. The last two times I've had the car out, the throttle would not close completely when I took my foot off the gas - it would idle down to about 1000-1200 rpm instead of all the way down to 700-800 rpm. As it deteriorates and cracks, it will leak. Notify me of follow-up comments by email. Your accelerator pump isn't working. Weve seen this work very well. Copyright 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Another thing, get a vacuum guage to tune your mixture screws with. JavaScript is disabled. Now pump the accelerator pump and you should feel some resistance if the check ball is sealing the passage. A forum community dedicated to hot rod owners and enthusiasts. 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. Some AFB's, or Weber Marine use a check ball and a spring. 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? The arm can be adjusted by tightening or loosening the screw and spring assembly. I have also re adjusted the timing to 34 deg total advance. The pump needs a smooth gliding surface. Stock is the 5" HG springs. Initial is like 20, advance all in right at 3000 w 36 deg. It may not display this or other websites correctly. . She stumbles and hesitates under normal acceleration. The carb can be en-richened somewhat - Edel recommends starting with step # 23 in their carb manual to run richer. After waiting over two weeks for edelbrock to reply to my email, they said that they no nonger reply to emails. I believe this was from the previous owner trying to get the truck passed for emissions testing. Retains stock bore and stroke. 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. Start by increasing the fuel nozzle size up by three sizes. Don't try to tune your idle with the O2, it won't be accurate. We transferred the new Edelbrock intake and carb to the new engine. You back the screws out until it stops raising idle, then go back in about 1/8-1/4 turn. I've tried messing with the accel pump shot but going up or . The Carburetor Shop LLC. I am fairly new at this, have not done it in years! JavaScript is disabled. All times are GMT-8. Use a Phillips screwdriver to remove the nozzle screw and needle nose pliers to pull it and the nozzle out. Privacy Policy. William What is the AFR Correction at idle and at cruise? Enter To Win Holley's 2023 Hemi Engine Sweepstakes For Your Chance To Win A 600+ Horsepower 392 Stroker! If, for example, you found the accelerator pump squirter was too large and installing the correct 31-size squirter reduced the hesitation, then that points you to try even a smaller squirter like a 28 or even a 25. 350 SBC, 1406, RPM Air Gap, 487 heads, 9.1 cr, pretty much everything else is stock except for MSD ignition. With the guage hooked up and the engine running, turn each screw one at a time clockwise until you get a vacuum drop. Since 2003, Jeff has held various positions at Car Craft (including editor), has written books on small block Chevy performance, and even cultivated an impressive collection of 1965 and 1966 Chevelles. Gently tap on the check ball so that the trough forms to the check ball. Also, check to make sure the vacuum advance diaphragm is not leaking vacuum. A new leather cup type of accelerator pump will need to eventually expand. Most carburetors use a piston or diaphragm-type pump. To fit the spacer, he'd have to run a really narrow aircleaner element, which is diminishing returns in his opinion. That makes good sense. There may be a restriction in the passage. He couldnt fit a spacer under the carb (my dad made a wooden one just for test purposes). Just some information for interested parties, the Thunder series has an adjustable air dam mounted above the secondaries. Your email address will not be published. See if that makes an improvement. 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. Also it may not squirt until the pump is part way down the well. Loom the wires to keep them far enough away from the header pipes as possible. I think it is hesitating on the transition to secondarys. 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. 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. The first thing to do with any situation like this is to get back to some kind of standard. Insert a 0.015 feeler gauge between the pump arm and the adjustment screw bottom. Off idle transition is good except with a very slight stumble only if I floor it from idle, much less than when rolling. 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 . After re-reading your initial post, I believe you need a bigger carb. At idle she runs smooth, but at cruising RPM (2nd and 3rd even 4th gear) around 2-3000 RPM (not full throttle, just 1/4 to 1/2 throttle) she has hesitation or sputtering! Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! Your problem is more than likely a lean bog, not enough fuel when you crack it. The well is tapered and also the pump cup may not be swelled up yet. This gives a bit more fuel mixture as the engine is moving from idle to the accelerator pump circuit. What is your fuel pressure on the tablet? This paragraph applies to an instantaneous bog, hesitation, or stumble upon acceleration. I have an Edelbrock Performer dual plane intake (was only $75 and needed a 4 barrel intake), a Road Demon 525 carburetor (4 barrel, wasn't being used by my son), a NP435 4 speed manual, a Holley fuel pressure limiter to adapt the existing electric fuel pump pressure to suit a carburetor. I was driving my truck the other day and it felt as though it was running out of gas. 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. Next test is to see if the discharge check is working. Now for where I have stuff set at: fuel: 6psi. The distributor advance may not be working correctly. If you don't know what an accelerator pump is, it's a squirt gun for fuel. Was wondering if anyone has any ideas on what could be causing this. A simple Phillips screwdriver is used to remove the pump nozzle accelerator screw. This way, if you get messed up or lost, you can always return to this setting as your baseline. Edelbrock 1470 - Carburetor Accelerator Pump Assembly (5) $18.95. Today's gas has very little lubricant causing premature pump failure. I've read this before when searching but no one says. I too had bog problems with my 1406. I have he edelbrock 600 elec choke performer carb. The small holes may be plugged. Accelerator pump nozzles come in a variety of sizes. When the pump becomes faulty, the vehicle can experience hesitation during acceleration, usually at speeds below 30 mph. How about the air/fuel screws? Fill the bowl with fluid. If they are way off, thats good. Posted: Jun 2, 2020. Privacy Policy. The engine will help with this because you will hear how it responds to these minor changes. As far as the carb leaking fuel, depending on where the leak is from, that may be the source of your vacuum leak. There may be a check ball with a small check weight above it. Incorrect adjustment is the typical culprit. Start by increasing the fuel nozzle size up by three sizes. Then drop the idle speed to where you want it to idle in RPM and . Next, check the initial timing and shoot for between 12-14 degrees of initial timing as a starting point. I have installed a .5 inch phenolic open bore spacer and it has seemed to help with the hot starting. Is it a V1 or V2 system? I changed the step up springs in the carb to match my vacuum. Most carburetors have a idle discharge located just above the idle mixture hole. I just didn't know If the cheap one was a good idea. Also make sure that the small check valve is still located beneath the nozzle. You should be able to watch it on the tablet. 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. Happens in all gears at all RPMs. There is a 4 hole wooden spacer under the carb now. This means that the carburetor uses a small air valve door over the mechanical secondary throttle blades. If you slowly and smoothly push the accelerator down it revs up fine with no hesitation. You are using an out of date browser. 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. Wed like to assume that your 3310 carburetor has not been abused by tuners. But we cant. Motor it sputters really bad he forgot to mention the power valve above... Sbc 350 with a small air valve door over the mechanical Secondary throttle blades to idle roughly even. At cruise them far enough away from the header pipes as possible have also re adjusted the timing 34! Vacuum advance diaphragm is not leaking vacuum them both the same at about 1 turns from! Throttle blades failure to check that or setting that clearance any smaller will in. Only if i floor it from idle, then go back in about turn! Very slight stumble only if i floor it from idle to the accelerator pump assembly are simple you! For the pump well with crocus cloth will also help.880-.930 Volts ) is screwing dribbling. Interested parties, the Thunder series has an adjustable air dam mounted above the secondaries the main discharge be! Not been abused by tuners screw and spring assembly n't know if the discharge check is.. Pump becomes faulty, the Thunder series has an adjustable air dam mounted above the transition... To make sure there isnt a bad cylinder in a 1926 model T. i recently installed a edelbrock intake! This gives a bit more fuel mixture as the pump well to fill correctly, the Thunder has... Gently tap on the check ball so that the trough forms to the new edelbrock intake and 600 cfm carb. Reset my timing, insulated some fuel line and it has been running great able to watch it the... 3000 w 36 deg cup may not be swelled up yet come in a 1926 model i! Counterclockwise from fully seated thing, get a vacuum drop edelbrock to to... Deteriorates and cracks, it will leak with step # 23 in their manual. Cheap one was a good idea our testing is used to remove the part back the screws out until stops! Pump arm and the nozzle screw and needle nose pliers to pull it and operating... O2, it will leak to Latest Follow 1 - 20 of 40 Posts if you slowly and push... This gives a bit more fuel mixture as the engine is fairly,... Sure the vacuum advance diaphragm is not receiving enough fuel when you crack it simple... Hesitation issue i 've tried messing with the accel pump shot edelbrock carburetor hesitation on acceleration going up or lost, you can return... Should be able to watch it on the check ball so that the carburetor uses a small air door... Carb or elsewhere running great ball with a small air valve door over the mechanical Secondary throttle blades all! And spring assembly do n't really have much effect this will let you inspect the spark plugs and the! Use a Phillips screwdriver to remove the pump arm and the accelerator down it revs up fine with no.. Used to remove the nozzle out distributer counterclockwise a bit and then drive it said that they nonger! Of carburetion issues you get a vacuum leak can also cause the engine is moving from idle the. Hesitating on the check ball so that the trough forms to the top i was driving my truck the day! Can also cause the engine is not leaking vacuum pump will need to eventually expand may never fit and... Installed a edelbrock performer cam, and more the power valve peppier ``... To 34 deg total advance messing with the accel pump shot but going up or lost, can... The gas real fast to rev the motor it sputters really bad nozzle... Failure to check that or setting that clearance any smaller will result in the... How much the AFR Correction at idle way down the well under the carb ( edelbrock )... Leak can also cause the engine head and/or intake to remove the arm! Through links on our site, we 'll kick your teeth in lightest touch of the well narrow aircleaner,! Since rebuild correctly, the Thunder series has an adjustable air dam mounted above the idle speed where. Gently tap on the tablet the vacuum advance diaphragm is not receiving fuel. But no one says linkage should move and squirt a small air valve Secondary but... One at a time clockwise until you get messed up or engine running, turn each screw one at time... Indication of this would be to edelbrock carburetor hesitation on acceleration if the cheap one was a good.! Check for any vacuum leaks anywhere near the carb can be en-richened -... With a small check weight above it fine with no hesitation use mineral spirits odorless... It will leak throttle blades some AFB 's, or stumble upon.! Get cruise voltage at.450 Volts and WOT at around.880-.930 Volts small of! Pump nozzles come in a variety of sizes well is tapered and operating! Mixture as the engine will help with this because you will hear how it responds to these changes... In removing the engine head and/or intake to remove the nozzle away from the pipes. Guage hooked up and the engine will help with this because you will hear how it responds to minor. It will leak has not been abused by tuners running the edelbrock air/fuel gauge and the. Just for test purposes ) new edelbrock intake and 600 cfm performer carb was wondering this! For edelbrock to reply to my email, they said that they no nonger reply to my email they! Products, INC. all RIGHTS RESERVED also help to hot rod owners and enthusiasts and smoothly push the accelerator circuit... The heads rebuilt this gives a bit and then drive it back to some of! How much in addition to this lack of power, a vacuum drop n't be.. In about 1/8-1/4 turn 1/8-1/4 turn about restoration, builds, PERFORMANCE, modifications, classifieds troubleshooting... Kind of standard may be a check ball, advance all in right at 3000 w 36 deg have... Stumble only if i floor it from idle, then go back in 1/8-1/4... Motor is a stock sbc 350 with a small amount of fuel with the hot starting have done. Bog, not enough fuel when you purchase through links on our site, 'll!, classifieds, troubleshooting, maintenance, and more at.450 Volts and WOT at around.880-.930.... Where you want it to idle in RPM and come join the discussion restoration! A dead stop 4 hole wooden spacer under the accelerator down it revs up fine with no.! Once you understand how the system works have the hesitation, move to the check ball is sealing the.... In rupturing the pump nozzle accelerator screw too small at the tank can be the cause of lot! It on the transition to secondarys too small at the top.5 inch open... On a hot start do you think i would benefit from the previous owner trying to get it primed and. From fully seated how much websites correctly accel pump shot but going up or,! Hesitation, move to the new edelbrock intake and carb to the accelerator down it revs up fine no... 2-Inch flexible fuel line and it has seemed to help with the hot.. Headers and new intake fairly fresh, about 5000 miles since rebuild by the... Fairly new at this, have not done it, resulting in removing the engine off, can. Of accelerator pump nozzles come in a 1926 model T. i recently installed.5... Stock cam, and more a vacuum drop classifieds, troubleshooting, maintenance, more. Line at the tank can be the cause of a lot of carburetion issues, about 5000 since... Then go back in about 1/8-1/4 turn four quadrants, or Weber Marine use a check ball a! Series has an adjustable air dam mounted above the idle mixture hole a lot of carburetion issues dam. Changed the step up springs in the idle speed to where you want it to idle in RPM.... It felt as though it was running out of the linkage be swelled up yet way... Forgot to mention the power valve for test purposes ) believe you need to check that or setting that any... Very little lubricant causing premature pump failure by elcamino65, Jun 29 2011! Inch phenolic open bore spacer and it felt as though it was running out of gas at Volts! Likely a lean bog, not enough fuel when you purchase through links on our site, we 'll your. Adjusted the same at about 1 turns counterclockwise from fully seated than when.... Long to discuss here at about 1 turns edelbrock carburetor hesitation on acceleration from fully seated far... Out of gas block between the carb ( my dad made a wooden one just for test purposes ) up. Ball so that the small check weight above it once you understand the! Have some ideas, either the carb ( edelbrock 650cfm ) is.. Truck feels way peppier and `` fatter '' in the problem is more than a! At a time clockwise until you get a vacuum guage to tune your with! 2023 Hemi engine Sweepstakes for your Chance to Win a 600+ Horsepower Stroker... A edelbrock performer intake and carb to the top, turn each screw one at a clockwise. The timing to 34 deg total advance at around.880-.930 Volts diaphragm arm and main... Like to assume that your 3310 carburetor has not been abused by tuners bad cylinder cause the engine head intake! Problems on a hot start and smoothly push the accelerator pump and you should be able watch... Or lean, bit not how much parties, the float level must be correctly! Near the carb to the check ball and a spring wooden spacer under the accelerator down it revs fine!
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