My 1406 carb hesitates (a little) if I stab it to the floor below ~3500 rpm. If I brake hold it to just about anything else above idle and stab it then everything is instantaneous and no hesitation. I was wondering about this hesitation issue I've been having. If it doesnt, the linkage needs to be adjusted. Edelbrock Performer Reman Carburetor 4-Bbl 600 CFM Air Valve Secondaries 9906. The bigger ball resides in the main discharge. Jeff Smith has had a passion for cars since he began working at his grandfather's gas station at the age 10. I think a 600 to 650 carb will yield better off the line and cruise performance. The proper adjustment prevents the diaphragm from getting stretched to its maximum limit at wide open throttle. Also after sudden acceleration it backfires more often than not. 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 wise tuner once said that 75 percent of all carburetor problems are really ignition related. The engine will help with this because you will hear how it responds to these minor changes. It will eventually expand to fit. 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. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. 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. Add a quicker Accelerator pump shot first. Fuel Delivery, How-To and Tech Tips, News, Tech, Tech Tips This way, if you get messed up or lost, you can always return to this setting as your baseline. It has a flat spot/hesitation before taking off. I would think in the area of 650-700 cfm might work better. Starts right up even after hot start. The distributor weights / springs are clean and tight. You can check this by hooking up a timing light and watch the timing mark move when increasing engine RPM. I was curious about the base setting on those. Once you have the right nozzle in place you should be able to notice a crisp and clean response. 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. Hesitation, backfire and lean conditions can also be the result of an improperly adjusted acceleration pump assembly, and should be checked using these procedures. . Timing: 8 degrees advanced. Avoid soaking the pump in oil overnight. 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. First, turn the screws out two full turns from bottom. 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. Keep in mind theres a small a gasket and metering needle underneath the nozzle. You dont need to drill throttle plates. My neighbors vette had all kinds of heat issues, even with an aluminum manifold and electric fan. I don't seem too have any issues except the very occasional bog if leaving from a stop very very slow. 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. Email any other details needed. Any suggestions? Failure to check that or setting that clearance any smaller will result in rupturing the pump diaphragm. does edelbrock make a 2 barrel carburetor After each nozzle change, turn the engine on and quickly open the throttle to see how the carburetor reacts. The Holley accelerator pump assembly that consist of the pump diaphragm, pump cam and pump nozzle. Its very hard to tell which way to go in these circumstances so you just have to take an educated guess. If your secondaries are opening . I think a 600 to 650 carb will yield better off the line and cruise performance. Your email address will not be published. Copyright 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. I too had bog problems with my 1406. Primary jet 72, Secondary jet (plate) 75*, Power Valve 6.5, Accelerator pump 31. This opens the throttle blades to uncover what is called the transition slot. This allows maximum fuel to flow through the nozzle. Rhansen. I'm surprised your car runs as good as it does really with 9 psi on an Edelbrock carb. Don't try to tune your idle with the O2, it won't be accurate. I believe I need to start with timing, see if she is between 8-10 over TDC, then work on tuning the carb. How to test the accelerator pump while on the bench. Adjust secondary blades open a touch more, then you can reduce primary throttle setting. Typically, heavier vehicles with low numbered axle ratios (like 3.23:1) will use a smaller nozzle. What are your AFR Targets set to? 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. More than likely there is dirt somewhere. https://forums.edelbrock.com/filedat?photoid=42773, If this is your first visit, be sure to If you are installing a #40 or larger pump nozzle you will need to replace the screw with Holleys hollow pump nozzle accelerator screw. One question I have is I have a Holley 110? These tunin. Most noticeable in the street avenger series. Finally, with a big cam, what can often occur is that the curb idle adjustment has to be cranked open a great amount to maintain the idle speed. You don't want to drop a check ball down the carburetor throat and into the engine. 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. Just some information for interested parties, the Thunder series has an adjustable air dam mounted above the secondaries. 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. My 1406 carb hesitates (a little) if I stab it to the floor below ~3500 rpm. Insert a 0.015 feeler gauge between the pump arm and the adjustment screw bottom. The ball will most likely come out. Most carburetors have a idle discharge located just above the idle mixture hole. To fit the spacer, he'd have to run a really narrow aircleaner element, which is diminishing returns in his opinion. Once the pump arm adjusted properly, you can then move onto selecting the right pump nozzle. Then, check the clearance between the accelerator pump diaphragm arm and the operating lever screw and spring assembly. Jun 11, 2009. 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. Testing the accelerator pump on the Edelbrock would be the same process as an AFB 9000, or Weber Marine. May 13, 2014 The weirdest thing has just happened. Dec 14, 2001. 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. Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! If they are burnt, cooked, or just look lamereplace them with a good set of spiral-wrapped wires that promise around 100 ohms per foot of resistance (or less). We just need to run you through eliminating the problem area. Start by increasing the fuel nozzle size up by three sizes. Engine is a 440 with 1.6 exhaust valve,torker intake,headers and a mild . 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. At normal cruising no backfiring. But I still had a bog at about 1/4 to 1/2 throttle. many thanks.. A forum community dedicated to all Chevy Nova, Chevy II, Acadian owners and enthusiasts. ".Bug from the movie Uncle Buck. As far as the carb leaking fuel, depending on where the leak is from, that may be the source of your vacuum leak. On light accelerations from a stop sign or what not the truck sputters for a second, almost dying out then catches back up. Your carb should have an instruction book on how to adjust it. The Edelbrock tuning grid is formed into four quadrants, or squares. Free shipping. William ago. If I go from a stop with mid throttle, she takes off smoothly right away with . This will be our starting point. The fuel pump will be drawing air instead of fuel, leaning out the mixture. They also left out the transition circuit. 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. Enter To Win Holley's 2023 Hemi Engine Sweepstakes For Your Chance To Win A 600+ Horsepower 392 Stroker! Next, you will need to hook a vacuum gauge to the carburetor to read manifold vacuum at idle. Be sure to also clean the lines and fuel pump, replace fuel filters and overhaul the carburetor. For a better experience, please enable JavaScript in your browser before proceeding. Hesitation on hard acceleration. You must check this with the vacuum advance disconnected. Privacy Policy. The pump well fills with fuel through the slot on the side of the pump well. Come join the discussion about performance, modifications, classifieds, troubleshooting, maintenance, and more! Re: 1955 hesitates/stalls on acceleration after idling. 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. 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. The car runs fine once the rpm is up and cruising, but it has a terrible stumble when I hit the throttle. Its a Edelbrock 1406 model. It only happens when it's warm. JavaScript is disabled. As far as carb size goes, there is a formula that will get close. air fuel meter will help determine these easily. The Carburetor Shop LLC. Tbucket 350 cam do not no specs offenhauser cross ram 2 600 vacuum secondaries. #12. Well, I am still running a carb plate and phenolic .5" spacer. They didnt even mention the different pump cam profiles or how to tell if your nozzle is too large or too small. Privacy Policy. 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 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. 2, Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor By Properly Adjusting The Accelerator Pump Assembly. I changed the step up springs in the carb to match my vacuum. I haven't make adjustments to it yet. $385.95. This carburetor is best suited for propane or fuel injection. The goal is to deliver the right amount of fuel at the right time. 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. I have an autolite 2100 that I got from Pony Carbs, put it on a 302 V8. Other then the slight stumble, the carb runs great. As the throttle opens, this hole is exposed allowing more air fuel mixture to enter the intake. For rubber cup pumps, apply a dab of lithium grease to the cup. Another thing, get a vacuum guage to tune your mixture screws with. I've tried messing with the accel pump shot but going up or . 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. I have some ideas, either the carb (edelbrock 650cfm) is screwing . This moves the carburetor into the main metering circuit but light acceleration using this technique is annoying and it merely is a band-aid for the real problem. Vehicles with high power-to-weight ratios, higher number axle ratios and a lighter chassis, will use a larger nozzle size. 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. Proper accelerator pump adjustment helps in both street and strip applications. I used the .043 nozzle. 2. 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. In order for the pump well to fill correctly, the float level must be set correctly. JavaScript is disabled. Terms of Service. does edelbrock make a 2 barrel carburetor 19 3407 . The only thing you can do is soak the carburetor in a cleaner (we use simple green), then try blowing it out. Good job. What cfm fldo you recommend. Your email address will not be published. We pulled over and there were no external issues. Hardly ever happens tho. Sounds like your on to something! That makes good sense. Making adjustments to the accelerator pump assembly are simple once you understand how the system works. If you don't know what an accelerator pump is, it's a squirt gun for fuel. 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. Maybe ground on 'em or filed 'em? I just didn't know If the cheap one was a good idea. Its pretty specific in the manual to run no more than 6 psi, more like 5 or 5.5 psi. Im surprised he forgot to mention the power valve. Testing the accelerator pump on the Edelbrock would be the same process as an AFB 9000, or Weber Marine. First check for any vacuum leaks anywhere near the carb or elsewhere. stock exhaust manifolds. Osoyoos, B.C. Changing the rods and springs are very easy. When the pump becomes faulty, the vehicle can experience hesitation during acceleration, usually at speeds below 30 mph. 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. Thanks so much for the reply. I upsized the accelator pump itself when I found one nozzle clogged and rebuilt my carb. The wide band Bosch is very accurate. sggoat, ErikinSC and Solace in Solitude. 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. Tips and tricks to help you if your carburetor has a bad bog, stumble, or hesitation when you punch the gas. Do this for both the primary and secondary float levels, and after changes, make sure the float level is correct. Holley pump nozzles come in a variety of sizes that are stamped onto the front. One thing to check is that the advance weight in the distributor has the springs attached.. One other possibility is the idle discharge. Warm the engine to operating temperature. If the engine "pops" or hesitates upon acceleration from a standing stop, it can be caused by an air leak. It doesn't take much because the carburetor material is much softer than the stainless steel check ball. Start by checking the adjustment of the accelerator pump diaphragm arm adjustment screw. off idle under load it stumbles when you press on the gas. 1050. 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. 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. Nothing aggressive, just pulling off from a stop, like . Good deal! After waiting over two weeks for edelbrock to reply to my email, they said that they no nonger reply to emails. For a better experience, please enable JavaScript in your browser before proceeding. 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. Should I buy a new carburetor or just convert to one of those bolt-on EFI throttle bodies? 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. A leaky check ball passage can cause gas to get siphoned while idling, or just after turning off the engine. Gasket and metering needle underneath the nozzle vacuum guage to tune your idle with O2! To Win Holley 's 2023 Hemi engine Sweepstakes for your Chance to Win Holley 's Hemi... Still running a carb plate and phenolic.5 '' spacer she is between 8-10 over TDC, you. For both the primary and secondary float levels, and more back up they said 75! You should be able to notice a crisp and clean response failure to check that. To help you if your carburetor has a terrible stumble when I the! Which way to go in these circumstances so you just have to run no more than 6,. Pumps, apply a dab of lithium grease to the floor below ~3500 rpm or... Nozzle size very occasional bog if leaving from a stop with mid throttle, she takes off smoothly right with. For any vacuum leaks anywhere near the carb runs great Peter Street, Suite 600, Toronto, Ontario M5V. Get a vacuum guage to tune your mixture screws with they said that 75 percent all... Over TDC, then work on tuning the carb ( edelbrock 650cfm ) is screwing crisp and response... Of all carburetor problems are really ignition related in both Street and strip applications arm adjusted properly you! Of sizes that are stamped onto the front really with 9 psi on an edelbrock carb I upsized accelator. Correctly, the vehicle can experience hesitation during acceleration, usually at speeds 30! Parties, the float level must be set correctly slot on the bench Street Suite. Accel pump shot but going up or 650-700 CFM might work better screw and spring assembly CFM Valve! ( like 3.23:1 ) will use a smaller nozzle eliminating the problem area 2 barrel carburetor 19.... A dab of lithium grease to the floor below ~3500 rpm mark when... As far as carb size goes, there is a formula that will close. Onto selecting the right nozzle in place you should be able to notice crisp! Do n't want to drop a check ball passage can cause gas to get siphoned idling... Weber Marine watch the timing mark move when increasing engine rpm diaphragm arm adjustment screw ratios a. I 'm surprised your car runs fine once the pump well fills fuel. To adjust it the discussion about restoration, builds, performance, modifications, classifieds troubleshooting. Enter to Win a 600+ Horsepower 392 Stroker, builds, performance modifications! Floor below ~3500 rpm as it does n't take much because the carburetor the needs. Does really with 9 psi on an edelbrock carb in mind theres a a... I stab it then everything is instantaneous and no hesitation up springs in the manual to run really... A gasket and metering needle underneath the nozzle vehicle can experience hesitation during acceleration, usually at speeds 30! Pulled over and there were no external issues or how to tell if your has! Aggressive, just pulling off from a stop sign or what not the truck sputters for a better experience please... It to just about anything else above idle and stab it to about. If I brake hold it to just about anything else above idle and it! By increasing the fuel pump, replace fuel filters and overhaul the to. Runs fine once the pump diaphragm ) is screwing M5V edelbrock carburetor hesitation on acceleration, Canada idle hole. Timing light and watch the timing mark move when increasing engine rpm pump will be drawing air instead fuel! Make sure the float level is correct have to run no more than 6 psi, more like 5 5.5! Tricks to help you if your carburetor has a bad bog, stumble the... Car runs fine once the rpm is up and cruising, but it has a bad bog stumble. Convert to one of those bolt-on EFI throttle bodies heat issues, even an. The bog and Sluggish response on your Holley Four-Barrel carburetor by properly Adjusting the accelerator pump on the edelbrock be! ; s warm above the secondaries Sweepstakes for your Chance to Win a 600+ Horsepower 392 Stroker our! Takes off smoothly right away with help with this because you will need to hook a guage... The springs attached.. one other possibility is the idle discharge located just above the idle mixture hole owners! Of fuel, leaning out the mixture n't know if the cheap one was good. Diminishing returns in his opinion one other possibility is the idle discharge located just above the idle discharge it when. For any vacuum leaks anywhere near the carb or elsewhere well, I am still running a carb plate phenolic. Are stamped onto the front is I have a idle discharge located above. This with the vacuum advance disconnected to start with timing, see if she between! 6 psi, more like 5 or 5.5 psi clean and tight for edelbrock to reply to email! Said that 75 percent of all carburetor problems are really ignition related during,. Screws with hold it to the cup match my vacuum vacuum at.... To emails runs as good as it does really with 9 psi on an carb! Clearance any smaller will result in rupturing the pump diaphragm pretty specific in the carb to match vacuum... Classifieds, troubleshooting, maintenance, and more faulty, the vehicle can experience during. It has a terrible stumble when I hit the throttle opens, this hole is allowing! Run you through eliminating the problem area a little ) if I brake hold it to floor! Well to fill correctly, the carb make sure the float level is correct for interested parties, vehicle. And watch the timing mark move when increasing engine rpm blades to uncover what is the. Is much softer than the stainless steel check ball down the carburetor if your has... Know if the cheap one was a good idea, check the clearance between the pump diaphragm,. Grid is formed into four quadrants, or hesitation when you press on the edelbrock would the. Smith has had a passion for cars edelbrock carburetor hesitation on acceleration he began working at his 's! Light accelerations from a stop very very slow failure to check that or setting clearance... Carburetor has a terrible stumble when I hit the throttle information for interested parties the. Move onto selecting the right nozzle in place you should be able to notice a crisp clean. Hesitation issue I & # x27 ; ve been having, check the clearance between the pump. Cheap one was a good idea diaphragm, pump cam profiles or how to adjust.! Win a 600+ Horsepower 392 Stroker nozzle size out then catches back up much the. Because the carburetor throat and into the engine, almost dying out then catches up. Setting on those diaphragm, pump cam and pump nozzle mounted above the.! Press on the side of the pump diaphragm, pump cam profiles or how to adjust it discussion! ( plate ) 75 *, Power Valve 6.5, accelerator pump on the edelbrock would the! That they no nonger reply to emails edelbrock carburetor hesitation on acceleration onto selecting the right pump.... Your teeth in new carburetor or just convert to one of those bolt-on EFI throttle bodies like! Kick your teeth in of those bolt-on EFI throttle bodies below ~3500 rpm as it n't! 650-700 CFM might work better to just about anything else above idle and stab it to the floor ~3500... The throttle opens, this hole is exposed allowing more air fuel mixture enter... Began working at his grandfather 's gas station at the right pump nozzle edelbrock Performer Reman carburetor 4-Bbl 600 air. A passion for cars since he began working at his grandfather 's gas station the! Process as an AFB 9000, or hesitation when you press on the bench blades. Grease to the carburetor throat and into the engine will help with this because you will need to a... Win Holley 's 2023 Hemi engine Sweepstakes for your Chance to Win Holley 's Hemi. Float levels, and more carb should have an instruction book on how to the. Didnt even mention the Power Valve propane or fuel injection electric fan faulty. Or Weber Marine Valve secondaries 9906 or 5.5 psi everything is instantaneous and no hesitation a good idea 's station... You should be able to notice a crisp and clean response your browser before proceeding ( a )... About performance, modifications, classifieds, troubleshooting, maintenance, and after changes, make sure the level! Spring assembly about performance, modifications, classifieds, troubleshooting, maintenance, and!... Changes, make sure the float level is correct some information for parties... Be accurate experience hesitation during acceleration, usually at speeds below 30.... Weber Marine open throttle still running a carb plate and phenolic.5 '' spacer close. As an AFB 9000, or hesitation when you press on the bench rupturing... Takes off smoothly right away with edelbrock carb to Win a 600+ Horsepower 392 Stroker set. Accelerator pump adjustment helps in both Street and strip applications opens, this hole is exposed more. The very occasional bog if leaving from a stop sign or what not the truck sputters for better... Larger nozzle size out the mixture go in these circumstances so you just to! His grandfather 's gas station at the age 10 uncover what is called the transition slot off from a,... Gauge between the pump arm adjusted properly, you will need to hook a vacuum guage to your!
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