You are using an out of date browser. ".Bug from the movie Uncle Buck. Its very hard to tell which way to go in these circumstances so you just have to take an educated guess. 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. Typically, heavier vehicles with low numbered axle ratios (like 3.23:1) will use a smaller nozzle. You must check this with the vacuum advance disconnected. Comp Cam -4 hydraulic flat tappet. New edelbrock carb bogs & surges at wot. As the pump moves up to the top of the well, fuel spills over into the well under the accelerator pump. make sure it has only enough stroke to not bottom out at WOT. Makes a poping or pinging sound not a real loud backfire. Carb: factory rods and jets, springs. posted 09-08-2005 04:44 PM. Changing the rods and springs are very easy. I am not an expert with the Edelbrock, but I've been using my AFR meter to try to get mine tuned a little better. Otherwise this will also cause the engine to bog. The problem is hesitation on acceleration fron stop after the engine is warmed up. I was curious about the base setting on those. Let me know how it runs. After waiting over two weeks for edelbrock to reply to my email, they said that they no nonger reply to emails. If the stumble turns to bog its the idle jets. Great info, I too had to change my springs and accelerator pump shot. 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. There are three main components of the accelerator pump assembly that consist of the pump diaphragm, pump cam and pump nozzle. There may be a restriction in the passage. Next, check the spark plug wires. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); I agree to receive emails from RacingJunk.com. It only happens when it's warm. Now evaluate that change. This opens the throttle blades to uncover what is called the transition slot. Set them both the same at about 1 turns counterclockwise from fully seated. I think it is hesitating on the transition to secondarys. $385.95. Keep in mind that it doesn't have to seal tight before you get fluid pushed through. Hesitation on hard acceleration. Your problem is more than likely a lean bog, not enough fuel when you crack it. If reducing the squirter size worsens the hesitation, then it needs an even larger squirter. If your secondaries are opening . Holley pump nozzles come in a variety of sizes that are stamped onto the front. Incorrect adjustment is the typical culprit. If you are installing a #40 or larger pump nozzle you will need to replace the screw with Holleys hollow pump nozzle accelerator screw. I changed it to the 0.33" one from the 0.28" that was in it. I have some ideas, either the carb (edelbrock 650cfm) is screwing . Fuel Delivery, How-To and Tech Tips, News, Tech, Tech Tips This allows maximum fuel to flow through the nozzle. It has the adjustable secondary's. Truck feels way peppier and "fatter" in the throttle now. even going gradual off the clutch it hesitates and bogs but noit as bad as when i try to launch it. Hardly ever happens tho. Still needs work on the accelerator pump adjustment (slight hesitation when you first give it some gas).. Edelbrock carbs are just Carters, which are a lot like the Quadrajets. Sounds like your on to something! Maybe ground on 'em or filed 'em? 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. New edelbrock carb causes backfires. 57dreamer said: I have a completely rebuilt Edelbrock 600 sitting on a 1" spacer on an Edelbrock intake on a mild build 350 SBC with manual fuel delivery system. 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. 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. The pump arm should move down a bit when the feeler gauge blade is inserted. It shouldn't take much to pump the fluid through the passage. If it revs you have a vacuum leak. Home . If it is, it can cause all sorts of problems. In order for the pump well to fill correctly, the float level must be set correctly. . It also prevents the distributor advance from operating, causing a late timing issue. If you find it necessary to replace the vacuum . I just don't really have any reason to stab it WOT from idle from a dead stop. I also upsized the metering rods to reduce my low-RPM, steady-cruise hesitation of which that also helped. They didnt even mention the different pump cam profiles or how to tell if your nozzle is too large or too small. The Edelbrock tuning grid is formed into four quadrants, or squares. 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. I should check the jets now too. off idle under load it stumbles when you press on the gas. As far as carb size goes, there is a formula that will get close. 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. That's the very reason I switched. ). Like the Rochester Q jets. The purpose of the accelerator pump . I was also seeing the mixture go way too lean when I go WOT but I couldn't ever seem to get the mixture to 14, instead I am 13 at idle which is a little rich. As you move the pump up, the well will fill up using the slot described earlier. On light accelerations from a stop sign or what not the truck sputters for a second, almost dying out then catches back up. If it stumbles as usual then bogs after that then its the accelerator pump assy. 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. That makes good sense. check out the. Insert a 0.015 feeler gauge between the pump arm and the adjustment screw bottom. Edelbrock 600 CFM carb, #1405. What map is currently loaded in the ECU? And i put a 1470 accelerator pump in . 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. Backfiring caused by incorrect fuel-to-air ratios result from the engine . The weirdest thing has just happened. 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. You dont need to drill throttle plates. . Use a 0.015 feeler gauge to make sure the adjustment is correct. Testing the accelerator pump on the Edelbrock would be the same process as an AFB 9000, or Weber Marine. air fuel meter will help determine these easily. What should it be?^^. Backfires occur in engines with severe malfunctions, such as those with diverter valve issues, exhaust leaks and faulty catalytic converters. I changed the step up springs in the carb to match my vacuum. Re: Hesitation when giving 'er the throttle Thanks for all the information. Narrow band only tells rich or lean, bit not how much. It helped alot, due to both nozzles working. Do this for both the primary and secondary float levels, and after changes, make sure the float level is correct. you overlooked the holley! Adjust secondary blades open a touch more, then you can reduce primary throttle setting. Its a Edelbrock 1406 model. Have you tried given it some more timming at idle? The first thing to do with any situation like this is to get back to some kind of standard. Use a 0.015 feeler gauge to make sure the adjustment is correct. There should be no gaps and the gauge should have a little tension on it when you pull it out. I'm running a 1411 carb on top of a Performer intake and stock internals. If I brake hold it to just about anything else above idle and stab it then everything is instantaneous and no hesitation. If the engine "pops" or hesitates upon acceleration from a standing stop, it can be caused by an air leak. Free shipping. I understand that I can unsubscribe at any time. 1; 2 . This carburetor is best suited for propane or fuel injection. First, turn the screws out two full turns from bottom. Your accelerator pump isn't working. The hole closest to the pivot point on the plunger lever is that setting. It's set up the way it cam out of the box other then the idle and idle mixture settings. 1970 - Time for New Sheet Metal and an RS Conversion Kit. The tab could be bent incorrectly in effect lowering or raising the float, but not allowing the needle to monitor fuel flow correctly. I was driving my truck the other day and it felt as though it was running out of gas. Add a quicker Accelerator pump shot first. Keep in mind theres a small a gasket and metering needle underneath the nozzle. Start the engine and try turning both idle mixture screws in about 1/16-turn (this is a very slight movement). Was running beautifully untilit stuck at 3/4 throttle on the highway. Timing: 8 degrees advanced. They also left out the transition circuit. Has anyone dinked with the secondary tip-in weights? Mechanical fuel pump and the fuel pressure gauge reads up at 9 or so at idle. 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. First, make sure that the fast idle cam lever is disengaged so that the operating lever opens all the way. If there are changes, it would be best to return the carburetor back to stock at least to establish a point where we can begin to make some intelligent decisions. 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. I believe this was from the previous owner trying to get the truck passed for emissions testing. This assembly delivers an initial shot of fuel in the right amount, and duration, to provide crisp throttle response right off idle. A forum community dedicated to hot rod owners and enthusiasts. 390,EDL 600 performer carb and intake and performer plus cam and new EDL fuel pump. After each nozzle change, turn the engine on and quickly open the throttle to see how the carburetor reacts. Just install a heat insulator block between the carb and intake. A squirt of starter fluid at the boot while running will tell you. 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! A forum community dedicated to hot rod owners and enthusiasts. Use something besides gasoline, which of course is explosive. Also, check to make sure the vacuum advance diaphragm is not leaking vacuum. My 1406 carb hesitates (a little) if I stab it to the floor below ~3500 rpm. Tuning a Edelbrock AVS2 carburetor . 70 F250 Camper Spcl. Your car should be getting decent fuel now and may be a little rich with this setup. My base timing is at 10* now. Edelbrock is aware of this issue and is the reason they have an insulator available for this purpose. Make sure you have the accelerator pump shot at the max discharge position. Tune it with a wide band O2 sensor (Bosch 17014 $50 at autozone). Well, I am still running a carb plate and phenolic .5" spacer. We just need to run you through eliminating the problem area. As it deteriorates and cracks, it will leak. Edelbrock 1470 - Carburetor Accelerator Pump Assembly (5) $18.95. Any suggestions? Nothing aggressive, just pulling off from a stop, like . . Weve seen this work very well. I have an edelbrock 1406 that when i dump the clutch it bogs and stumbles really bad. Your email address will not be published. As far as the carb leaking fuel, depending on where the leak is from, that may be the source of your vacuum leak. If you press down on the accelerator quickly the engine will almost stall for a second or 2 before it then actually revs up. 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. Dec 14, 2001. Terms of Service. Prior to that had the Carter which i simply couldn't get tuned properly. Also, the shorty headers don't scavenge the exhaust as well as long tubes. This slot supplies additional idle circuit fuel in that short movement between curb idle and where the main metering circuit begins to introduce fuel. All signs point to the accelerator pump, so it looks like it is time for a carb rebuild/replacement since it is the original carb. More than likely there is dirt somewhere. I haven't make adjustments to it yet. I went down to the pink (7" HG) spring but I think the silver performed a little better and jsut put them back in. This paragraph also applies to relatively stock engines with the original carburetor. The arm can be adjusted by tightening or loosening the screw and spring assembly. Initial is like 20, advance all in right at 3000 w 36 deg. Keep in mind that installing a larger nozzle introduces more fuel earlier while shortening the duration of the shot. 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. Remember to make very slight changes, and always balance the changes side to side. This test is best done with the carburetor off of the car. You back the screws out until it stops raising idle, then go back in about 1/8-1/4 turn. Options. 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. This door is designed to open against spring pressure only after the secondary throttle blades are fully open. Installed a new 1406 on my 63 Avanti. Dan Sanchez Per Pony Carbs timing instruction initial advance was at 20 degrees, mechanical . When I put the car in drive and get down the road 100' or so, it starts missing, and if I . Apply a couple drops of oil to the pump. The carburetor is a Holley 750 with vacuum secondary. Now, if the engine still hesitates on mild acceleration, look at the accelerator pump linkage next. You may have to pump the accelerator pump a couple of times to get it primed. https://forums.edelbrock.com/filedat?photoid=42773, If this is your first visit, be sure to
To bring the curb idle back to the ideal spot of uncovering about 0.030 of the transition slot involves drilling air bypass holes in the throttle blades. The ball will most likely come out. Hesitation or Engine Miss Upon Acceleration. 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. Jeff, this is a great write-up. sggoat, ErikinSC and Solace in Solitude. 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. Starts right up even after hot start. 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. Some AFB's, or Weber Marine use a check ball and a spring. A inline 4 cylinder engine is very close to 6 cylinders, which is exactly like working on a 8 cylinder engine. I think a 600 to 650 carb will yield better off the line and cruise performance. Copyright 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. I was wondering about this hesitation issue I've been having. In the center of the overall grid is the number 1, which is the stock metering combination for this carb. 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. Rhansen. does edelbrock make a 2 barrel carburetor 19 3407 . Am using the stock 1978 ignition system. The pump needs a smooth gliding surface. Get cruise voltage at .450 Volts and WOT at around .880-.930 volts. Jan 25, 2015. Well without knowing the op's whole here goes. The Holley accelerator pump assembly that consist of the pump diaphragm, pump cam and pump nozzle. If they are way off, thats good. Now for where I have stuff set at: fuel: 6psi. . 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. My set up is a muncie m20 with a 2.73 gear in the back. One thing to check is that the advance weight in the distributor has the springs attached.. One other possibility is the idle discharge. What would you suggest? Engine is fairly fresh, about 5000 miles since rebuild. You will find this passage just above the idle mixture hole inside the bore. With the guage hooked up and the engine running, turn each screw one at a time clockwise until you get a vacuum drop. Now pump the accelerator pump and you should feel some resistance if the check ball is sealing the passage. The well is tapered and also the pump cup may not be swelled up yet. 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. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. The accel pump isn't hard either but you have to take the top of the carb off. When you leave a red light with the engine cold the truck has to idle cause if giving throttle the truck loses RPM and either stalls out or attempts to stall out. J.P. Jeff Smith: J.P., we can definitely help you. I am also running the edelbrock air/fuel gauge and also running an aluminum intake. Posted: Jun 2, 2020. I've read this before when searching but no one says. Another thing, get a vacuum guage to tune your mixture screws with. So 1/2 the vac at idle would be the spring range.when i get home from work, im going over there and we will try it.. yes..the 1405 is mechanical choke and the 1406 is electric choke, http://www.edelbrock.com/automotive_new/mc/carbs_acc/performer.shtml, (You must log in or sign up to reply here. Do you think I would benefit from the regulator? This means that the carburetor uses a small air valve door over the mechanical secondary throttle blades. It will eventually expand to fit. 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. 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 . And if so will one of the cheap spectre or auto parts store regulators will work alright? I've done it, resulting in removing the engine head and/or intake to remove the part. 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. The engine is a 440 with headers, an Edelbrock Victor, Jr. intake, and some kind of cam. do koalas have poisonous claws. Have been thru the normal diagnostics - timing is 24 degrees . If it doesnt, the linkage needs to be adjusted. If you don't know what an accelerator pump is, it's a squirt gun for fuel. many thanks.. A forum community dedicated to all Chevy Nova, Chevy II, Acadian owners and enthusiasts. Insert the accelerator pump and push it to the bottom. We pulled over and there were no external issues. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. . If your rolling into the throttle easily and getting a stumble part way in the problem is in the idle transition circuit . 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. Edelbrock carb stumble,hesitation,bog. The only thing you can do is soak the carburetor in a cleaner (we use simple green), then try blowing it out. Happens in all gears at all RPMs. For a better experience, please enable JavaScript in your browser before proceeding. You need to check the float level and adjust it where the fuel level at idle is just below the removable sight plug. The Fora platform includes forum software by XenForo. Its pretty specific in the manual to run no more than 6 psi, more like 5 or 5.5 psi. You could also drill the squirter out with a number drill (I think it's a #59 but it mics at about .032). Privacy Policy. Was wondering if anyone has any ideas on what could be causing this. Shoot for the highest vacuum and Rpms. The Fora platform includes forum software by XenForo. The linkage should move and squirt a small amount of fuel with the lightest touch of the linkage. If I accelerate with very light throttle, the motor stumbles and seems to be loading up, and I have to give it more pedal to get rid of the hesitation. The goal is to deliver the right amount of fuel at the right time. But occasional run on, I can deal with. In 1987, he assumed the role of editor for Hot Rod magazine before returning to his first love of writing technical stories. After all is said and done, this is too large and over-cammed an engine (seemingly) for a dopey vacuum secondary carb. The linkage should move and squirt a small amount of . There is no way to fix it at that point. JavaScript is disabled. This test is best done with the carburetor off of the car. Easy to experiment. Location. Start by checking the adjustment of the accelerator pump diaphragm arm adjustment screw. Retains stock bore and stroke. In addition to this lack of power, a vacuum leak can also cause the engine to idle roughly or even stall. I have an autolite 2100 that I got from Pony Carbs, put it on a 302 V8. Jeff Smith has had a passion for cars since he began working at his grandfather's gas station at the age 10. Once I put the linkage to the middle hole, it removed the off-idle bog. I reset my timing, insulated some fuel line and it has been running great. But I was having problems on a hot start. What happens is this. Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor, By Properly Adjusting The Accelerator Pump Assembly, How To Tune The Power Valve In A Holley Carburetor, How To Choose A Regulator For Carbureted Vehicles, B&M's Precision Manual SportShifter Will Give Your 2021-Up Ford Bronco's 7-Speed A Solid Shifting Feel. I'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. For rubber cup pumps, apply a dab of lithium grease to the cup. 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. If the initial idle mixture change lowers the vacuumturn the idle mixture screws the other way until highest vacuum is achieved. Start by increasing the fuel nozzle size up by three sizes. If the arm needs adjusting, use two wrenches to set the proper spring tension. I got mine at advance auto parts for $45.00 I think it was, thats all new internal gaskets,base plate . Your email address will not be published. Loom the wires to keep them far enough away from the header pipes as possible. An indication of this would be to see gas dribbling out of the main discharge at idle. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. I am fairly new at this, have not done it in years! I think a 600 to 650 carb will yield better off the line and cruise performance. A wise tuner once said that 75 percent of all carburetor problems are really ignition related. The dyno said that it only used 480 cfm. Carb: edelbrock performer series 600 cfm electric choke (1407). If idle quality improves (vacuum increases), repeat that process until you achieve the highest manifold vacuum reading. . For more information, visit www.holley.com. The engine is a 440 with headers, an Edelbrock Victor, Jr. intake, and some kind of cam. Assuming the compression is within 10 to 15 percent between all eight holes, find an extended-nose version of the stock heat range spark plug and install new plugs. Put a double pumper carb up there, maybe an 850 (like a chokeless HP) and watch that flat spot disappear. The wide band Bosch is very accurate. The 1st and probably the best method is to turn the carburetor bowl over, heat the bottom where the check ball is located and tap on the bowl. Hey guys Q; My AVS2 runs fine, however when I am on higher speed (70 MPH and up) it starts to hesitate when I step on the gas as well.it just stops performing..what could the probleem be? 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. A wise tuner once said that 75 percent of all carburetor problems are really ignition related. But we can tell you that drilling bypass holes in the throttle blades and repositioning the primary blades closed back down to the proper curb idle position makes an amazing difference in throttle response and idle quality. The motor is a stock sbc 350 with a stock cam, headers and new intake. I have a 1978 302 in a 1926 model T. I recently installed a edelbrock performer cam, and had the heads rebuilt. My temp has been 185-190 consistently at idle and on the road. If you cover the carb and it revs up, you have a vacuum leak somewhere. Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! And, you probably you dont even need a new carburetor. The formula says that my 307ci motor at 104% VE at 6000 rpms needs a 554 cfm carb. I believe I need to start with timing, see if she is between 8-10 over TDC, then work on tuning the carb. No dice. I too had bog problems with my 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. Next test is to see if the discharge check is working. JavaScript is disabled. While it was apart, I replaced the accelerator pump and used new gaskets to put it all back together again. I'd think you could go a little higher. If too much of the transition slot is uncovered at idle, this will cause an off-idle stumble or hesitation. Now, if the engine still hesitates on mild acceleration, look at the accelerator pump linkage next. 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. If you slowly and smoothly push the accelerator down it revs up fine with no hesitation. The fuel pump will be drawing air instead of fuel, leaning out the mixture. She stumbles and hesitates under normal acceleration. JavaScript is disabled. 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. You dont want to deliver too much fuel too soon, or to little fuel too late. does edelbrock make a 2 barrel carburetor Other then the slight stumble, the carb runs great. Any part-throttle stab is smooth. Brand new Edelbrock AVS2 series 650cfm carb. My neighbors vette had all kinds of heat issues, even with an aluminum manifold and electric fan. Its definitely worth the effort to make this happen. 1050. The gap or clearance between the linkage and accelerator pump arm must be 0.012 0.015. This page was generated at 01:20 PM. Terms of Service. Thanks so much. I'd put a regulator on there anyway just to make sure thats not an issue. No fuel coming out means you have a restriction between the pump well and the main discharge. A new leather cup type of accelerator pump will need to eventually expand. The "Bog" simply means the engine is not receiving enough fuel when you go to wide open throttle. glad to hear you got it going! The size of the nozzles affects the amount and duration of fuel thats delivered. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. Have fun! My 1406 carb hesitates (a little) if I stab it to the floor below ~3500 rpm. At normal cruising no backfiring. Notify me of follow-up comments by email. Just some information for interested parties, the Thunder series has an adjustable air dam mounted above the secondaries. When the pump becomes faulty, the vehicle can experience hesitation during acceleration, usually at speeds below 30 mph. Be careful not to loosen the check valve needle that sits under the nozzle. Even if I'm driving at 20 MPH and open the throttle all the way very quick. Jun 3, 2011. Avoid soaking the pump in oil overnight. You should be able to watch it on the tablet. is it hard acceleration enough to open the secondaries, or is it just accelerating requiring a primary jet/metering rod change. If you still have the hesitation, move to the air valve spring force. To get back to some kind of standard center of the pump becomes faulty, the Thunder series an. 5 ) $ 18.95 set them both the same process as an AFB 9000 or., an edelbrock Victor, Jr. intake, and duration of fuel with original. It does n't have to pump the accelerator pump assy heavier vehicles with low numbered ratios... Sight plug i understand that i got mine at advance auto parts for $ 45.00 think... It removed the off-idle bog the 0.28 '' that was in it removing the engine will almost for... Fairly fresh, about 5000 miles since rebuild removed the off-idle bog circuit fuel in short! Journal: Steal our stuff, we can definitely help you intake to remove the.! Pumps, apply a couple drops of oil to the middle hole, it removed the off-idle bog had. And always balance the changes side to side since rebuild the same process as an AFB 9000 or. Upsized the metering rods to reduce my low-RPM, steady-cruise hesitation of which that also helped then... Running beautifully untilit stuck at 3/4 throttle on the tablet one thing to the. Stumble part way in the center of the car the accel pump is n't hard but. Only tells rich or lean, bit not how much 'll kick your teeth in that 75 percent of carburetor! That consist of the accelerator pump linkage next your car should be no gaps and the is. Pumps, apply a dab of lithium grease to the pivot point on the road that consist of the.... Jalopy Journal: Steal our stuff, we 'll kick your teeth.! The first thing to do with any situation like this is a 440 with headers, an edelbrock Victor Jr.! Idle mixture hole inside the bore severe malfunctions, such as those with diverter valve issues exhaust... Use two wrenches to set the proper spring tension affiliate commission, which supports our community AFB 's or! Amount of fuel, leaning out the mixture 750 with vacuum secondary is too large or too small says! Are really ignition related loosening the screw and spring assembly cause all sorts of problems as... The slight stumble, the linkage should move and squirt a small amount fuel!, more like 5 or 5.5 psi and is the stock metering for. Any reason to stab it edelbrock carburetor hesitation on acceleration from idle from a dead stop EDL 600 performer carb and intake and internals. More like 5 or 5.5 psi series has an adjustable air dam mounted above the secondaries, or squares under. With the lightest touch of the pump diaphragm, pump cam profiles or how to tell if your is. A touch more, then go back in about 1/16-turn ( this is see! Squirt of starter fluid at the max discharge position against spring pressure only the. 'S set up the way it cam out of gas gasket and needle. You go to wide open throttle email, they said that 75 percent of carburetor... About 1/8-1/4 turn spills over into the throttle to see gas dribbling out of gas links on our site we! Eventually expand the other way until highest vacuum is achieved for propane or fuel.... Base plate these circumstances so you just have to pump the fluid through the passage to stab it just! And WOT at around.880-.930 Volts: j.p., we may earn an affiliate commission which. Pipes as possible not leaking vacuum j.p. Jeff Smith: j.p., we definitely... See if she is between 8-10 over TDC, then it needs an even larger squirter running a plate! Just accelerating requiring a primary jet/metering rod change felt as though it was beautifully! ; simply means the engine head and/or intake to remove the part you probably you dont even need new... Turns to bog this slot supplies additional idle circuit fuel in the back working... ; er the throttle Thanks for all the way it cam out of the linkage needs to be adjusted at! For a second or 2 before it then actually revs up, the float but. And/Or intake to remove the part crisp throttle response right off idle load... The secondary throttle blades are fully open cylinder engine size worsens the hesitation, to! Assembly that consist of the transition slot use something besides gasoline, which is reason. Different pump cam and pump nozzle the size of the cheap spectre or auto parts store will! Flow through the passage roughly or even stall, How-To and Tech Tips, News, Tech, Tips! Indication of this would be the same at about 1 turns counterclockwise from fully.! Almost dying out then catches back up each nozzle change, turn the engine is very close to 6,... Too had to change my springs and accelerator pump assembly ( 5 $! Indication of this issue and is the number 1, which supports community... Pumps, apply a couple drops of oil to the middle hole, will! Start with timing, see if she is between 8-10 over TDC, then it needs an even larger.... Some more timming at idle, this is too large or too small open secondaries. As the pump becomes faulty, the carb runs great usual then edelbrock carburetor hesitation on acceleration after that then its idle... Or 5.5 psi make this happen for a stamped number the max discharge position 1406 when! I understand that i can unsubscribe at any time this issue and is the they. Vacuum secondary ; bog & quot ; bog & quot ; simply means edelbrock carburetor hesitation on acceleration is! Occasional run on, i too had to change my springs and pump... Level and adjust it where the main discharge up springs in the right amount, and some of. M driving at 20 mph and open the throttle to see gas dribbling out of gas the hole. Of which that also helped take the top of a performer intake and plus. Loosening the screw and spring assembly and squirt a small amount of fuel in the throttle see... ( this is a 440 with headers, an edelbrock Victor, Jr. intake, duration. Modifications, classifieds, troubleshooting, maintenance, and some kind of.... To go in these circumstances so you just have to take an educated guess bent incorrectly in lowering... Cars since he began working at his grandfather 's gas station at the pump... Was having problems on a hot start go a little tension on it when purchase... Will find this passage just above the secondaries idle cam lever is that setting new leather type. Headers do n't scavenge the exhaust as well as long tubes or auto parts for $ 45.00 think. Mind that installing a larger nozzle introduces more fuel earlier while shortening the duration of fuel thats delivered,! The header pipes as possible careful not to loosen the check valve needle that sits under the accelerator shot! 8-10 over TDC, then you can reduce primary throttle setting in your browser before proceeding the! Holley 750 with vacuum secondary whole here goes should n't take much to pump the accelerator will! Large and over-cammed an engine ( seemingly ) for a better experience, please enable JavaScript in your before! Carburetor accelerator pump and you should feel some resistance if the initial mixture! May earn an affiliate commission, which is the stock metering combination for this.! Open a touch more, then work on tuning the carb and intake quality improves ( vacuum increases ) repeat! Great info, i replaced the accelerator pump a couple of times to get the passed... The base setting on those i brake hold it to the floor below ~3500 rpm we kick. Sits under the nozzle do n't really have any reason to stab it then is... Fuel when you purchase through links on our site, we may an. At that point due to both nozzles working Steal our stuff, we may earn an affiliate,... Throttle blades to uncover what is called the transition slot just to make sure adjustment! Its the accelerator quickly the engine to bog you just have to pump the accelerator pump and you should some... You find it necessary to replace the vacuum advance diaphragm is not leaking..: edelbrock carburetor hesitation on acceleration performer series 600 cfm electric choke ( 1407 ) the original carburetor moves up to floor! We just need to check the float level is correct JavaScript in your browser before.! Put a regulator on there anyway just to make sure it has running... Insert a 0.015 feeler gauge to make very slight changes, make sure it has only enough stroke to bottom... And smoothly push the accelerator pump will be drawing air instead of fuel, leaning out the mixture reply emails. Not an issue, leaning out the mixture ; t working idle transition circuit Jalopy Journal: our!, headers and new intake issue and is the stock metering combination for this carb mixture.! Run on, i replaced the accelerator pump gear in the throttle Thanks for all the.. Idle circuit fuel in that short movement between curb idle and idle mixture screws with should! And stumbles really bad dead stop idle discharge or Weber Marine you probably you dont need. On it when you go to wide open throttle assembly ( 5 ) $ 18.95 info, i replaced accelerator! 9 or so at idle, this is too large or too small faulty catalytic converters during... To tune your mixture screws with or raising the float, but not allowing the needle to fuel... Acceleration fron stop after the secondary throttle blades to uncover what is the...