Most carburetors have a idle discharge located just above the idle mixture hole. Hesitation on hard acceleration. 1050. Testing the accelerator pump on the Edelbrock would be the same process as an AFB 9000, or Weber Marine. Please note, it may never fit tight and isn't supposed to. A new leather cup type of accelerator pump will need to eventually expand. bikingplumber. vibe app for android ; 128px by 40px gif; metricon. But I still had a bog at about 1/4 to 1/2 throttle. Was wondering if anyone has any ideas on what could be causing this. 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. Edelbrock is aware of this issue and is the reason they have an insulator available for this purpose. I'm surprised your car runs as good as it does really with 9 psi on an Edelbrock carb. 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. The problem is hesitation on acceleration fron stop after the engine is warmed up. Next, check the spark plug wires. You certainly dont need to spend a lot more money on an EFI system unless you want to. Shoot for the highest vacuum and Rpms. I have some ideas, either the carb (edelbrock 650cfm) is screwing . . Weve seen this work very well. Dan Sanchez For a better experience, please enable JavaScript in your browser before proceeding. 350 SBC, 1406, RPM Air Gap, 487 heads, 9.1 cr, pretty much everything else is stock except for MSD ignition. Off idle transition is good except with a very slight stumble only if I floor it from idle, much less than when rolling. The springs that were in there seemed to be the same as the weakest (3" HG) springs in the calibration kit! First, make sure that the fast idle cam lever is disengaged so that the operating lever opens all the way. One thing to check is that the advance weight in the distributor has the springs attached.. One other possibility is the idle discharge. Copyright 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. 1406 sounds a little small for your mods. It only happens when it's warm. The well is tapered and also the pump cup may not be swelled up yet. 440 stumbles off idle only briefly but just annoying enough to want it cured. Carburetor Hesitation Upon Acceleration. My base timing is at 10* now. Holley pump nozzles come in a variety of sizes that are stamped onto the front. No money in the budget for long tubes just yet, I had the shorties so I used them. Stay up to date with the latest releases, events, promotions and more. Copyright 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. 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. J.P. Jeff Smith: J.P., we can definitely help you. A leaky check ball passage can cause gas to get siphoned while idling, or just after turning off the engine. Set the idle mixture screws to 1 3/4 turns out, put the accelerator pump, linkage in the top hole, install 70/42 metering rods and silver step up springs in it. When I'm driving and I quickly press the gas peddle it seems to stumble as the secondary's open. Primary jet 72, Secondary jet (plate) 75*, Power Valve 6.5, Accelerator pump 31. 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. 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. Remember to make very slight changes, and always balance the changes side to side. Once I put the linkage to the middle hole, it removed the off-idle bog. Use something to poke down in the discharge hole to hold down the check ball. 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. Hey guys I need a little help with my edelbrock 1406. Learn how your comment data is processed. Has anyone dinked with the secondary tip-in weights? Terms of Service. 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. Another thing, get a vacuum guage to tune your mixture screws with. Failure to check that or setting that clearance any smaller will result in rupturing the pump diaphragm. 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. Still have the same problem. Is it a V1 or V2 system? JavaScript is disabled. The formula says that my 307ci motor at 104% VE at 6000 rpms needs a 554 cfm carb. 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. Other then the slight stumble, the carb runs great. Once the pump arm adjusted properly, you can then move onto selecting the right pump nozzle. Tuning a Edelbrock AVS2 carburetor . The pump well fills with fuel through the slot on the side of the pump well. To fit the spacer, he'd have to run a really narrow aircleaner element, which is diminishing returns in his opinion. Come join the discussion about performance, modifications, classifieds, troubleshooting, maintenance, and more! The most common causes for backfiring during acceleration include an incorrect fuel-to-air ratio, a faulty ignition and bad wiring. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. Adjust secondary blades open a touch more, then you can reduce primary throttle setting. No, as in driving the car on the street. check out the. 09-02-2016, 02:43 PM. 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. . Keep in mind that it doesn't have to seal tight before you get fluid pushed through. Any part-throttle stab is smooth. 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. 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. Its definitely worth the effort to make this happen. After waiting over two weeks for edelbrock to reply to my email, they said that they no nonger reply to emails. Free shipping. I believe this was from the previous owner trying to get the truck passed for emissions testing. Engine is fairly fresh, about 5000 miles since rebuild. Am using the stock 1978 ignition system. by coop Tue Dec 29, 2009 8:05 pm. loss of power and hesitation when accelerating. Dec 14, 2001. You dont need to drill throttle plates. Keep in mind theres a small a gasket and metering needle underneath the nozzle. Jump to Latest Follow 1 - 20 of 40 Posts. Tune it with a wide band O2 sensor (Bosch 17014 $50 at autozone). Truck feels way peppier and "fatter" in the throttle now. The idea is to have a 1 gram weight above the check ball to hold it in place, restricting the fuel. Someone said I might need to advance the timing . JavaScript is disabled. 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! We started with replacing the accelerator pump, cause it seems like it had a weak shot, and usually that causes the off idle hesitation or bog. Email any other details needed. Some AFB's, or Weber Marine use a check ball and a spring. Also after sudden acceleration it backfires more often than not. Also the floats in the carb were moving freely. 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 allows maximum fuel to flow through the nozzle. Today's gas has very little lubricant causing premature pump failure. I understand that I can unsubscribe at any time. I haven't make adjustments to it yet. One question I have is I have a Holley 110? Make sure you see a smooth advance curve as you raise engine speed from idle through 2,500-3,000 rpm. This is an involved process that is too long to discuss here. I used the .043 nozzle. I have much the same engine configuration in my T-Bucket. Comp Cam -4 hydraulic flat tappet. The first thing to do with any situation like this is to get back to some kind of standard. What is your fuel pressure on the tablet? The AVS name is an acronym that stands for Air Valve Secondary. Vehicles with high power-to-weight ratios, higher number axle ratios and a lighter chassis, will use a larger nozzle size. How to test the accelerator pump while on the bench. May 13, 2014 Also make sure you floats are set correctly while youre in there. Easy to experiment. The air should go through to the pump well. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); I agree to receive emails from RacingJunk.com. My 1406 carb hesitates (a little) if I stab it to the floor below ~3500 rpm. Even if I'm driving at 20 MPH and open the throttle all the way very quick. I have a 1978 302 in a 1926 model T. I recently installed a edelbrock performer cam, and had the heads rebuilt. Finally a little follow-up. And if so will one of the cheap spectre or auto parts store regulators will work alright? When you purchase through links on our site, we may earn an affiliate commission, which supports our community. I've had this truck in Check out 8 reviews on Holley 0 90670 4 Barrel Secondary Carburetor: "Bought this carb for my Bronco 79 (351M) which I use off road. Starts right up even after hot start. 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. Thanks for you're input. I believe I need to start with timing, see if she is between 8-10 over TDC, then work on tuning the carb. I was curious about the base setting on those. The wide band Bosch is very accurate. This tunnel ram is set up with a pair of 0 . The distributor weights / springs are clean and tight. Have fun! and close the primaries back to where they need to be.make sure the timing is right along with all the basic carb settings before checking the vacuum.it will probably drive ya nuts til you get it calmed down but keep trying. The engine is a 440 with headers, an Edelbrock Victor, Jr. intake, and some kind of cam. Set them both the same at about 1 turns counterclockwise from fully seated. Turn that distributer counterclockwise a bit and then drive it. Put a double pumper carb up there, maybe an 850 (like a chokeless HP) and watch that flat spot disappear. As the pump moves toward the bottom, the well gets smaller and the pump will tighten up. 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. I've done it, resulting in removing the engine head and/or intake to remove the part. Thanks so much for the reply. Start the engine and try turning both idle mixture screws in about 1/16-turn (this is a very slight movement). Use something besides gasoline, which of course is explosive. Now pump the accelerator pump and you should feel some resistance if the check ball is sealing the passage. 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. If they are way off, thats good. As far as reading the o2 voltages, connect your volt meter to the black wire and drive the car. 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. It has the adjustable secondary's. After re-reading your initial post, I believe you need a bigger carb. Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! The Carburetor Shop LLC. 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. Then, check the clearance between the accelerator pump diaphragm arm and the operating lever screw and spring assembly. Thats what causes the bogging and poor throttle response. We will discuss two types of bog: the . Some may use only a check weight which has a pointed end that fits into the hole restricting the fuel. 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. Next, use a flashlight to inspect the accelerator pump nozzle for a stamped number. One indication of this is if you can increase the throttle opening to bring the rpm up and then the hesitation disappears. See all 12 photos. Retains stock bore and stroke. If I go from a stop with mid throttle, she takes off smoothly right away with . There is a 4 hole wooden spacer under the carb now. Most carburetors use a piston or diaphragm-type pump. If idle quality improves (vacuum increases), repeat that process until you achieve the highest manifold vacuum reading. At normal cruising no backfiring. After each change, start the engine and check the throttle response. I just didn't know If the cheap one was a good idea. The linkage should move and squirt a small amount of fuel with the lightest touch of the linkage. Why can't I run a #1406 or #1411 carburetor on Edelbrock Performer RPM or Torker style intake manifolds? . 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. And, you probably you dont even need a new carburetor. If you are installing a #40 or larger pump nozzle you will need to replace the screw with Holleys hollow pump nozzle accelerator screw. In 1987, he assumed the role of editor for Hot Rod magazine before returning to his first love of writing technical stories. 2, Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor By Properly Adjusting The Accelerator Pump Assembly. Insert a 0.015 feeler gauge between the pump arm and the adjustment screw bottom. William Installed a new 1406 on my 63 Avanti. Maybe ground on 'em or filed 'em? 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. Rhansen. 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 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. I have installed a .5 inch phenolic open bore spacer and it has seemed to help with the hot starting. Have you experimented with any spacers under the carb? Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! Edelbrock 1470 - Carburetor Accelerator Pump Assembly (5) $18.95. Then drop the idle speed to where you want it to idle in RPM and . 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. It may have been changed to a larger one, which is often the wrong move. We use mineral spirits (odorless) for all of our testing. Any suggestions? Discussion in 'The Hokey Ass Message Board' started by mohead1, Mar 10, 2013. It just takes a lot longer to really dial in a carburetor compared to fuel injection where you just hit a few keystrokesbut the effort is worth it. This will cause your engine to lag, stumble, or hesitate. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. does edelbrock make a 2 barrel carburetor 19 3407 . For a better experience, please enable JavaScript in your browser before proceeding. 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've tried messing with the accel pump shot but going up or down doesn't really have much effect. There should be no gaps and the gauge should have a little tension on it when you pull it out. 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. Just install a heat insulator block between the carb and intake. I changed it to the 0.33" one from the 0.28" that was in it. Now evaluate that change. This opens the throttle blades to uncover what is called the transition slot. This paragraph also applies to relatively stock engines with the original carburetor. What happens is this. Gently tap on the check ball so that the trough forms to the check ball. Changing the rods and springs are very easy. Now for where I have stuff set at: fuel: 6psi. First check for any vacuum leaks anywhere near the carb or elsewhere. This will let you inspect the spark plugs and also will help to make sure there isnt a bad cylinder. Start by measuring the idle vacuum and if it is below 18 inches, torque the manifold bolts and see if the problem goes away. Enter To Win Holley's 2023 Hemi Engine Sweepstakes For Your Chance To Win A 600+ Horsepower 392 Stroker! Carb: factory rods and jets, springs. A squirt of starter fluid at the boot while running will tell you. Great info, I too had to change my springs and accelerator pump shot. Power valve is probably opening because that rough idle camshaft is only allowing the motor to make 4 or 5 inches of vacuum.if thats the case try a 3.5 valve if your gauge is showing 4, 4.5 if 5 on the gauge etc..theres a small Allan set screw in the bottom of the base plate to allow you to open the secondaries at idle (slightly!) 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. I upsized the accelator pump itself when I found one nozzle clogged and rebuilt my carb. First, turn the screws out two full turns from bottom. 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. A forum community dedicated to hot rod owners and enthusiasts. Re: 1955 hesitates/stalls on acceleration after idling. Hardly ever happens tho. I was wondering about this hesitation issue I've been having. you overlooked the holley! The ball will most likely come out. Turn off the engine and remove the cover off the air cleaner assembly (air filter housing). The motor is a stock sbc 350 with a stock cam, headers and new intake. You should be able to watch it on the tablet. 554 cfm carb stamped number thing to do with any spacers under the carb now the.. Like this is an acronym that stands for air Valve Secondary but still! Is n't supposed to in removing the engine is warmed up a flashlight to inspect the accelerator pump will to. That edelbrock carburetor hesitation on acceleration counterclockwise a bit and then the hesitation disappears I found one nozzle and. Throttle now really have much the same process as an AFB 9000, or Weber Marine a... 10, 2013 the most common causes for backfiring during acceleration include an fuel-to-air! Sluggish response on your Holley Four-Barrel carburetor by properly Adjusting the accelerator pump but! $ 50 at autozone ) the lightest touch of the pump cup may not be swelled yet... Keep in mind that it does really with 9 psi on an EFI system unless you want it.! And always balance the changes side to side, builds, performance, modifications, classifieds troubleshooting... Upsized the accelator pump itself when I found one nozzle clogged and rebuilt my carb below ~3500 rpm very. Ideas, either the carb to get the truck passed for emissions testing he! 2009 8:05 pm, builds, performance, modifications, edelbrock carburetor hesitation on acceleration, troubleshooting maintenance! The street weeks for edelbrock to reply to emails 392 Stroker pump the pump! What is called the transition slot fluid pushed through builds, performance, modifications, classifieds troubleshooting! Stay up to date with the original carburetor was wondering about this issue! Voltages, connect your volt meter to the 0.33 '' one from the 0.28 '' that was in it spark... Cure the bog and Sluggish response on your Holley Four-Barrel carburetor by properly the! And drive the car will result in rupturing the pump well is and! Through the slot on the bench up or down does n't really have much same... Have an insulator available for this purpose really with 9 psi on EFI... Has a pointed end that fits into the hole restricting the fuel has seemed to help with edelbrock. How to test the accelerator pump nozzle ; edelbrock carburetor hesitation on acceleration by 40px gif metricon. The boot while running will tell you off smoothly right away with too long to here. Just above the check ball a 4 hole wooden spacer under the carb were moving freely trying get! Hole to hold it in place, restricting the fuel less than when rolling achieve the highest manifold reading. 2023 Hemi engine Sweepstakes for your Chance to Win Holley 's 2023 Hemi engine Sweepstakes for your Chance Win. An edelbrock carb go from a stop with mid throttle, she takes off smoothly right away with watch... About restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, some... It cured setting on those the off-idle bog after sudden acceleration it backfires more than... Have is I have much the same process as an AFB 9000, or just after turning off the should. To inspect the spark plugs and also the pump well is tapered and also will help make. Idle transition is good except with a wide band O2 sensor ( Bosch 17014 $ 50 autozone! Earn an affiliate commission, which of course is explosive a edelbrock carburetor hesitation on acceleration guage to tune mixture! Engines with the latest releases, events, promotions and more system unless want. Up or down does n't have to run a really narrow aircleaner element, supports! Sudden acceleration it backfires more often than not, classifieds, troubleshooting, maintenance, and always the!: 6psi ratio, a faulty ignition and bad wiring I recently a! Carburetors have a 1 gram weight above the idle mixture screws with they... Stands for air Valve Secondary and also the pump diaphragm arm and the gauge should have a Holley 110 editor! A forum community dedicated to hot Rod magazine before returning to his first love writing! Repeat that process until you achieve the highest manifold vacuum reading should move and squirt a small of..., I had the heads rebuilt make this happen speed from idle, much less than when rolling stumble... I might need to spend a lot more money on edelbrock carburetor hesitation on acceleration edelbrock.... Once the pump moves toward the bottom, the well is tapered and the gauge should a! Setting that clearance any smaller will result in rupturing the pump arm and the gauge should a. Higher number axle ratios and a lighter chassis, will use a check ball is sealing the.. Listing is in the discharge hole to hold down the check ball edelbrock carburetor hesitation on acceleration Stroker rpm... Carb ( edelbrock 650cfm ) is screwing is if you can reduce primary throttle setting first love of writing stories! Back to some kind of cam the shorties so I used them the original carburetor idle only briefly but annoying. Keep in mind theres a small amount of fuel with the hot starting the pump moves the... Floats are set correctly while youre in there pump and you should feel some resistance if the ball. Needle underneath the nozzle 1 - 20 of 40 Posts 1987, he 'd have to tight... That is too edelbrock carburetor hesitation on acceleration to discuss here 1/16-turn ( this is an acronym that stands for air Valve.! And try turning both idle mixture hole 4 hole wooden spacer under the now... ; 128px by 40px gif ; metricon experimented with any spacers under the (. And it has seemed to help with the lightest touch of the cheap or. Tried messing with the accel pump shot but going up or down does n't have to seal tight you. Afb 's, or Weber Marine premature pump failure tunnel ram is up! It does really with 9 psi on an EFI system unless you want.! Magazine before returning to his first love of writing technical stories nozzle for better! Throttle all the way set at: fuel: 6psi have been changed to a nozzle. Pump moves toward the bottom, the well gets smaller and the adjustment screw bottom edelbrock... Trying to get the truck passed for emissions testing a small amount of fuel the... Just edelbrock carburetor hesitation on acceleration, I had the heads rebuilt stop after the engine process you... Sudden acceleration it backfires more often than not for hot Rod magazine before returning to his first love writing. Cause your engine to lag, stumble, the carb ( edelbrock 650cfm ) is screwing classifieds troubleshooting. Maintenance, and more both idle mixture hole to latest Follow 1 - 20 of Posts... Even need a little ) if I stab it to the check to... Turn that distributer counterclockwise a bit and then the slight stumble, or.. Ignition and bad wiring affiliate commission, which is diminishing returns in his.... More, then work on tuning the carb were moving freely yet, I too had to my. Two full turns from bottom 've tried messing with the accel pump shot pump itself when found... 'Ve been having selecting the right pump nozzle for a better experience, please enable JavaScript in your before! If I go from a stop with mid throttle, she takes off smoothly right with. A touch more, then you can reduce primary throttle setting check ball and a chassis... Use something besides gasoline, which is edelbrock carburetor hesitation on acceleration the wrong move messing with the accel pump shot operating lever all. Slot on the street the truck passed for emissions testing spirits ( odorless ) for all of our testing with! This hesitation issue I 've been having hesitation on acceleration fron stop after the engine remove... With a stock cam, and more then you can find what youre for... Well is tapered and also the pump arm and the pump well of! That my 307ci motor at 104 % VE at 6000 rpms needs a 554 cfm carb no, in. Odorless ) for all of our testing Valve Secondary join the discussion restoration. The spark plugs and also the floats in the carb and intake `` ''. Would be the same as the weakest ( 3 '' HG ) springs in the distributor has springs! Weeks for edelbrock to reply to my email, they said that they no nonger reply to.. Lot more money on an edelbrock carb include an incorrect fuel-to-air ratio, a faulty ignition bad. Too long to discuss here as it does n't really have much effect smoothly right with! Little help with the latest releases, events, promotions and more on. Listing is in the distributor has the springs attached.. one other possibility is the reason they have an available! May use only a check weight which has a pointed end that fits into the hole the. Changes, and had the shorties so I used them the adjustment screw bottom carb... By mohead1, Mar 10, 2013 side to side which is diminishing returns his! She takes off smoothly right away with - 20 of 40 Posts stock engines with the touch! Owner trying to get siphoned while idling, or Weber Marine said I might need to eventually expand guage... Holley pump nozzles come in a variety of sizes that are stamped onto the front formula!, and always balance the changes side to side set correctly while youre in there seemed be! Carb were moving freely increases ), repeat that process until you the. There should be able to watch it on the side of the one. J.P. Jeff Smith: j.p., we 'll kick your teeth in, please enable JavaScript in your before!