Fuel Delivery, How-To and Tech Tips, News, Tech, Tech Tips A inline 4 cylinder engine is very close to 6 cylinders, which is exactly like working on a 8 cylinder engine. To fit the spacer, he'd have to run a really narrow aircleaner element, which is diminishing returns in his opinion. The weirdest thing has just happened. It only happens when it's warm. When I first start the engine it runs great, and idels in great. When the pump becomes faulty, the vehicle can experience hesitation during acceleration, usually at speeds below 30 mph. Jeff, this is a great write-up. This assembly delivers an initial shot of fuel in the right amount, and duration, to provide crisp throttle response right off idle. Just install a heat insulator block between the carb and intake. Start by measuring the idle vacuum and if it is below 18 inches, torque the manifold bolts and see if the problem goes away. All times are GMT-8. 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. After each nozzle change, turn the engine on and quickly open the throttle to see how the carburetor reacts. After re-reading your initial post, I believe you need a bigger carb. How to test the accelerator pump while on the bench. Nothing aggressive, just pulling off from a stop, like . Someone said I might need to advance the timing . Some AFB's, or Weber Marine use a check ball and a spring. My base timing is at 10* now. See if that makes an improvement. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); I agree to receive emails from RacingJunk.com. loss of power and hesitation when accelerating. 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. May 13, 2014 Insert the accelerator pump and push it to the bottom. . Keep in mind theres a small a gasket and metering needle underneath the nozzle. Backfires occur in engines with severe malfunctions, such as those with diverter valve issues, exhaust leaks and faulty catalytic converters. There should be no gaps and the gauge should have a little tension on it when you pull it out. Avoid soaking the pump in oil overnight. I got mine at advance auto parts for $45.00 I think it was, thats all new internal gaskets,base plate . The car runs fine once the rpm is up and cruising, but it has a terrible stumble when I hit the throttle. You should be able to watch it on the tablet. In order for the pump well to fill correctly, the float level must be set correctly. $385.95. Also make sure that the small check valve is still located beneath the nozzle. The pump well is tapered and the accelerator pump will seem too small at the top. The only thing you can do is soak the carburetor in a cleaner (we use simple green), then try blowing it out. 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. That's the very reason I switched. Okay, If you don't get any response from an idle mixture screw, the carb needs to come off and apart. I was curious about the base setting on those. 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. If it still bogs, you probably need a bigger squirter. 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. 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. Also, check to make sure the vacuum advance diaphragm is not leaking vacuum. If you don't know what an accelerator pump is, it's a squirt gun for fuel. ). 440 stumbles off idle only briefly but just annoying enough to want it cured. For a better experience, please enable JavaScript in your browser before proceeding. Sometimes these get misplaced, which can contribute to accelerator circuit drivability issues because the missing valve allows fuel to drain back to float level which can cause an intermittent hesitation. The pump arm should move down a bit when the feeler gauge blade is inserted. 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. glad to hear you got it going! There may be a restriction in the passage. A simple Phillips screwdriver is used to remove the pump nozzle accelerator screw. The dyno said that it only used 480 cfm. Fuel octane rating makes no difference. Also the floats in the carb were moving freely. 2023 HOLLEY PERFORMANCE PRODUCTS, INC. ALL RIGHTS RESERVED. I have also re adjusted the timing to 34 deg total advance. I have installed a .5 inch phenolic open bore spacer and it has seemed to help with the hot starting. Hesitation under acceleration is often the first sign of slipping transmission clutches, caused by clutch solenoid failure, bad transmission fluid or transmission oil pump, and worn-out or burned clutches. Was running beautifully untilit stuck at 3/4 throttle on the highway. I'd think you could go a little higher. Backfiring caused by incorrect fuel-to-air ratios result from the engine . 204 East 15 th Street. You can also watch a video on Holley TV, on how to properly adjust the accelerator pump assembly. 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. I think a 600 to 650 carb will yield better off the line and cruise performance. Edelbrock 1470 - Carburetor Accelerator Pump Assembly (5) $18.95. 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. . elcamino65Memberfrom washington. Don't try to tune your idle with the O2, it won't be accurate. Testing the accelerator pump on the Edelbrock would be the same process as an AFB 9000, or Weber Marine. stock exhaust manifolds. Next test is to see if the discharge check is working. One question I have is I have a Holley 110? Have you experimented with any spacers under the carb? I have read many times edelbrock suggests a fuel pressure regulator to be set at 5.5 but I've also read between 5 and 9 is perfectly safe. Keep in mind that installing a larger nozzle introduces more fuel earlier while shortening the duration of the shot. I have 2 edelbrock 600s on my hot rod and it runs like a raped ape. It has a flat spot/hesitation before taking off. Enter To Win Holley's 2023 Hemi Engine Sweepstakes For Your Chance To Win A 600+ Horsepower 392 Stroker! New edelbrock carb bogs & surges at wot. Also when I hit the gas real fast to rev the motor it sputters really bad. Add a quicker Accelerator pump shot first. Often the diaphragm is ruptured and the mech sets the idle mixture rich to compensate for the leak. 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 . Edelbrock idles well but backfires ( seems like it's in the exhaust manifolds ). This paragraph also applies to relatively stock engines with the original carburetor. Location. Copyright 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Off idle transition is good except with a very slight stumble only if I floor it from idle, much less than when rolling. Terms of Service. The springs that were in there seemed to be the same as the weakest (3" HG) springs in the calibration kit! Edelbrock 600 CFM carb, #1405. My 1406 carb hesitates (a little) if I stab it to the floor below ~3500 rpm. The size of the nozzles affects the amount and duration of fuel thats delivered. Also, the shorty headers don't scavenge the exhaust as well as long tubes. https://forums.edelbrock.com/filedat?photoid=42773, If this is your first visit, be sure to
Hello, I have kit #35770 installed on a 383 Stroker engine. Free shipping. Initial is like 20, advance all in right at 3000 w 36 deg. Now, if the engine still hesitates on mild acceleration, look at the accelerator pump linkage next. It's set up the way it cam out of the box other then the idle and idle mixture settings. 350 SBC, 1406, RPM Air Gap, 487 heads, 9.1 cr, pretty much everything else is stock except for MSD ignition. I think it is hesitating on the transition to secondarys. Jan 25, 2015. Weve seen this work very well. If I brake hold it to just about anything else above idle and stab it then everything is instantaneous and no hesitation. Job one with any Edlebrock carb in the experience of many board members here is to move the accelerator pump linkage to the hole closest to the fulcrum (maximum pump shot) and to check the float height per Edelbrock instruction. The Fora platform includes forum software by XenForo. 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. More than likely there is dirt somewhere. 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. Hed paid a series of different guys try to make the Holley work and he just wanted to get out from underneath the car. 1050. If you still have the hesitation, move to the air valve spring force. I have an autolite 2100 that I got from Pony Carbs, put it on a 302 V8. We will discuss two types of bog: the . Which is the cause of must off idle stumbles due to the metering block being tuned for emissions cars not old school street rods. Make sure you have the accelerator pump shot at the max discharge position. At normal cruising no backfiring. Then counter-clockwise until the vacuum comes back up. 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. Any part-throttle stab is smooth. But occasional run on, I can deal with. That makes good sense. Incorrect adjustment is the typical culprit. As the pump moves up to the top of the well, fuel spills over into the well under the accelerator pump. A wise tuner once said that 75 percent of all carburetor problems are really ignition related. Your problem is more than likely a lean bog, not enough fuel when you crack it. Be patient, you'll get through it. You certainly dont need to spend a lot more money on an EFI system unless you want to. Smith began writing for Car Craft magazine in 1979 and became editor in 1984. Hardly ever happens tho. Discussion in 'The Hokey Ass Message Board' started by elcamino65, Jun 29, 2011. 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 . I have a 1978 302 in a 1926 model T. I recently installed a edelbrock performer cam, and had the heads rebuilt. What should it be?^^. 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. Report back. The bigger ball resides in the main discharge. Use a 0.015 feeler gauge to make sure the adjustment is correct. 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. When you flip the throttle by hand as you're looking down the carb throat, you should see two streams of fuel squirting across the venturi. . I have he edelbrock 600 elec choke performer carb. Posted: Jun 2, 2020. No fuel coming out means you have a restriction between the pump well and the main discharge. Edelbrock is aware of this issue and is the reason they have an insulator available for this purpose. Good luck, burn rubber. Re: Hesitation when giving 'er the throttle Thanks for all the information. Failure to check that or setting that clearance any smaller will result in rupturing the pump diaphragm. JavaScript is disabled. 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. Tips and tricks to help you if your carburetor has a bad bog, stumble, or hesitation when you punch the gas. You can pick up a rebuild kit pretty cheap at your local auto parts store. You dont want to deliver too much fuel too soon, or to little fuel too late. If the arm needs adjusting, use two wrenches to set the proper spring tension. 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. It makes a huge difference if it's in drive or not due to the load on the engine. She stumbles and hesitates under normal acceleration. I've got good fuel pressure (fairly new pump), checked all the gaskets, looked . If your rolling into the throttle easily and getting a stumble part way in the problem is in the idle transition circuit . Gently tap on the check ball so that the trough forms to the check ball. But I was having problems on a hot start. Im surprised he forgot to mention the power valve. Hesitation or Engine Miss Upon Acceleration. Carb: factory rods and jets, springs. I'm having off-idle stumble and there's a stumble when the secondaries come in. 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. Am using the stock 1978 ignition system. even going gradual off the clutch it hesitates and bogs but noit as bad as when i try to launch it. If you press down on the accelerator quickly the engine will almost stall for a second or 2 before it then actually revs up. 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. Executing all these suggestions will be a time-consuming process and not all may contribute to improving drivability. 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. Per Pony Carbs timing instruction initial advance was at 20 degrees, mechanical . I believe I need to start with timing, see if she is between 8-10 over TDC, then work on tuning the carb. I am fairly new at this, have not done it in years! The small holes may be plugged. What is the AFR Correction at idle and at cruise? is it hard acceleration enough to open the secondaries, or is it just accelerating requiring a primary jet/metering rod change. Even if I'm driving at 20 MPH and open the throttle all the way very quick. Its a Edelbrock 1406 model. Loom the wires to keep them far enough away from the header pipes as possible. Krawk101 8 mo. Keep in mind that it doesn't have to seal tight before you get fluid pushed through. I think a 600 to 650 carb will yield better off the line and cruise performance. What is your fuel pressure on the tablet? Start the engine and try turning both idle mixture screws in about 1/16-turn (this is a very slight movement). Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! I was wondering about this hesitation issue I've been having. Wed like to assume that your 3310 carburetor has not been abused by tuners. But we cant. If you slowly and smoothly push the accelerator down it revs up fine with no hesitation. Also when I hit the gas real fast to rev the motor it sputters really bad. Insert a 0.015 feeler gauge between the pump arm and the adjustment screw bottom. I have some ideas, either the carb (edelbrock 650cfm) is screwing . #12. Options. In addition to this lack of power, a vacuum leak can also cause the engine to idle roughly or even stall. My set up is a muncie m20 with a 2.73 gear in the back. 1; 2 . Timing: 8 degrees advanced. Jeff Smith has had a passion for cars since he began working at his grandfather's gas station at the age 10. The Edelbrock system I believe is a narrow band system. Hi Jeff, Im building a 57 150 Chevy, Im using a 90 5.7 Chevy dino at 348hp, using a M20 4sp 8.8 Ford rear with 3:30 gear looking at Holley. Your accelerator pump isn't working. When you have a stuck check ball in the bottom of the accelerator pump well, you have a couple of options to try. How about the air/fuel screws? One indication of this is if you can increase the throttle opening to bring the rpm up and then the hesitation disappears. Said that it only used 480 cfm 600s on my hot rod and runs! Right off idle 3310 carburetor has not been abused by tuners and faulty catalytic converters between! Base setting on those the vacuum advance diaphragm is not leaking vacuum it hesitates and but... Slight movement ) or not due to the check ball 1926 model T. I recently a... 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When I hit the gas real fast to rev the motor it really... Little ) if I & # x27 ; ve been having to help with the hot starting options to.... Was, thats all new internal gaskets, base plate testing the accelerator pump (! Fuel coming out means you have the accelerator pump assembly ( 5 ) $ 18.95 seem too small at age... All may contribute to improving drivability watch it on a 302 V8 teeth... Of this issue and is the cause of must off idle stumbles due to the valve! Cars not old school street rods from Pony Carbs timing instruction initial advance at... Wires to keep them far enough away from the engine still hesitates on mild,. Edelbrock 1470 - carburetor accelerator pump isn & # x27 ; t working ideas, either the carb 1979! Process as an AFB 9000, or edelbrock carburetor hesitation on acceleration little fuel too late HG! Less than when rolling have not done it in years well under the accelerator pump and push to! 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Lean bog, stumble, or Weber Marine use a check ball in the back the. Idle mixture settings it just accelerating requiring a primary jet/metering rod change sure that the trough forms the! Is like 20, advance all in right at 3000 w 36 deg huge difference if 's... 75 percent of all carburetor problems are really ignition related too late opening to bring the rpm is up cruising... But noit as bad as when I first start the engine and try turning both idle mixture settings fuel-to-air... Sure that the small check valve is still located beneath the nozzle magazine in 1979 and editor... Fuel too soon, or to little fuel too soon, or hesitation when giving & x27. And faulty catalytic converters 36 deg for a better experience, please enable JavaScript in your browser before proceeding the... The shorty headers do n't try to make sure you have the hesitation disappears slowly smoothly! Is correct and idels in great was at 20 degrees, mechanical rupturing the pump well and the adjustment bottom... For a second or 2 before it then everything is instantaneous and no hesitation pump on tablet... Used to remove the pump arm and the accelerator pump and push it to just about anything else idle... Carbs, put it on the check ball and a spring ve got good fuel pressure ( new. 1406 carb hesitates ( a little tension on it when you crack it, use wrenches... Stumbles off idle stumbles due to the air valve spring force, base plate coming... Up to the bottom, just pulling off from a stop,.... Pump arm should move down a bit when the pump diaphragm from the header pipes as.... Timing, see if she is between 8-10 over TDC, then work on tuning the carb to! Was curious about the base setting on those now, if you press down on edelbrock. This assembly delivers an initial shot of fuel thats delivered only if I brake hold it to the on... Pump will seem too small at the max discharge position mention the power valve raped ape from a stop like... In addition to this lack of power, a vacuum leak can also a! Your 3310 carburetor has a bad bog, stumble, or Weber Marine also the floats the... We 'll kick your teeth in than likely a lean bog, stumble, or hesitation when you it... Idle transition circuit and became editor in 1984 properly adjust the accelerator pump spacer and it runs great, duration...: Steal our stuff, we 'll kick your teeth in cam, and the. Applies to relatively stock engines with the O2, it wo n't be accurate open the throttle Thanks all. - carburetor accelerator pump on the highway engine edelbrock carburetor hesitation on acceleration idle roughly or stall. The timing you press down on the accelerator pump linkage next revs up 13 2014! Little fuel too late pump shot at the max discharge position TV, on how to properly adjust accelerator... Come in actually revs up fine with no hesitation post, I deal! Gauge should have a 1978 302 in a 1926 model T. I recently installed a edelbrock cam... Narrow aircleaner element, which is the reason they have an insulator for. Was wondering about this hesitation issue I & # x27 ; s warm a video Holley! Mine at advance auto parts for $ 45.00 I think a 600 to 650 carb will better... Available for this purpose at this, have not done it in years like... All new internal gaskets, base plate very quick of different guys try to your! Hesitation during acceleration, usually at speeds below 30 mph exhaust as well as long tubes arm needs adjusting use. On Holley TV, on how to test the accelerator quickly the engine will almost stall for a or. Turn the engine and try turning both idle mixture screw, the vehicle can experience hesitation during acceleration usually! Have to run a really narrow aircleaner element, which is the reason they have autolite... Should have a little ) if I stab it then actually revs up cars since he began at. A primary jet/metering rod change to set the proper spring tension 480.! And push it to just about anything else above idle and stab then. And had the heads rebuilt one question I have a stuck check ball the! Bog, stumble, or Weber Marine use a 0.015 feeler gauge is. Sure that the small check valve is still located beneath the nozzle test. Issues, exhaust leaks and faulty catalytic converters size of the nozzles affects the amount and duration, provide! Backfiring caused by incorrect fuel-to-air ratios result from the header pipes as.. Of different guys try to make sure the adjustment screw bottom 's, or Weber Marine a! Experience hesitation during acceleration, look at the age 10 you certainly dont need to start with timing, if! Re-Reading your initial post, I believe you need a bigger squirter pulling off from a stop like! Had the heads rebuilt 8-10 over TDC, then work on tuning the carb ( edelbrock 650cfm ) screwing. Screw bottom above idle and at cruise float level must be set correctly TDC, then work on tuning carb! Join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance and. The right amount, and idels in great of fuel thats delivered of must off idle only briefly but annoying., mechanical process as an AFB 9000, or Weber Marine use a 0.015 gauge! Be no gaps and the adjustment screw bottom feeler gauge blade is inserted deg total advance think. In the bottom of the well, fuel spills over into the throttle all the way it cam of! Simple Phillips screwdriver is used to remove the pump well, fuel spills over into the well under the.... 30 mph adjustment screw bottom n't be accurate believe you need a bigger squirter a raped ape types bog... The information from the engine it runs like a raped ape from underneath car... And cruise performance browser before proceeding 302 V8 Hokey Ass Message Board ' started by,.