edelbrock carburetor hesitation on acceleration
edelbrock carburetor hesitation on acceleration
Copyright 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. But I was having problems on a hot start. That should not happen. Thanks for you're input. Report back. The carburetor is a Holley 750 with vacuum secondary. about 3200 rpm, I can hear the secondaries starting to kick in and then it stops accelerating and alternately bogs/surges but won't accelerate unless I lift off the throttle. Keep in mind that it doesn't have to seal tight before you get fluid pushed through. Changing the rods and springs are very easy. For a better experience, please enable JavaScript in your browser before proceeding. If it doesnt, the linkage needs to be adjusted. Turn off the engine and remove the cover off the air cleaner assembly (air filter housing). JavaScript is disabled. If your vehicle only seems to hesitate in top gear, or over about 45 mph, you may have a problem with the lock-up clutches in the torque . The camshaft specs are: duration @50 is 215 intake and 224 exhaust, advertised is 284 intake and 296 exhaust with .470 intake lift and .490 exhaust lift, with 1.6 rockers, lobe separation angle is 108 intake and 116 exhaust, this is a roller camshaft. Loom the wires to keep them far enough away from the header pipes as possible. I would think in the area of 650-700 cfm might work better. Smith began writing for Car Craft magazine in 1979 and became editor in 1984. They didnt even mention the different pump cam profiles or how to tell if your nozzle is too large or too small. 302 bog/hesitation. Thanks so much for the reply. I reset my timing, insulated some fuel line and it has been running great. Hi Jeff, Im building a 57 150 Chevy, Im using a 90 5.7 Chevy dino at 348hp, using a M20 4sp 8.8 Ford rear with 3:30 gear looking at Holley. Be sure to also clean the lines and fuel pump, replace fuel filters and overhaul the carburetor. The Edelbrock AVS2 carb was a great choice for your 383. Okay, If you don't get any response from an idle mixture screw, the carb needs to come off and apart. First, turn the screws out two full turns from bottom. I am fairly new at this, have not done it in years! The ball will most likely come out. Thats what causes the bogging and poor throttle response. 2023 HOLLEY PERFORMANCE PRODUCTS, INC. ALL RIGHTS RESERVED. 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 just don't really have any reason to stab it WOT from idle from a dead stop. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. Each of the four . I have 2 edelbrock 600s on my hot rod and it runs like a raped ape. My temp has been 185-190 consistently at idle and on the road. The arm can be adjusted by tightening or loosening the screw and spring assembly. The motor is a stock sbc 350 with a stock cam, headers and new intake. Copyright 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Now evaluate that change. Once you have the right nozzle in place you should be able to notice a crisp and clean response. Even if I'm driving at 20 MPH and open the throttle all the way very quick. Thats what causes the bogging and poor throttle response. 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. Vehicles with high power-to-weight ratios, higher number axle ratios and a lighter chassis, will use a larger nozzle size. Email any other details needed. The Accel pump is squirting just fine, and i have adjusted to the longest pump stroke for more fuel spray. 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. If the arm needs adjusting, use two wrenches to set the proper spring tension. I have also re adjusted the timing to 34 deg total advance. This opens the throttle blades to uncover what is called the transition slot. Edelbrock Carburetor . Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! This article leaves out a bunch of detail. For rubber cup pumps, apply a dab of lithium grease to the cup. 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. Fuel Delivery, How-To and Tech Tips, News, Tech, Tech Tips Use a 0.015 feeler gauge to make sure the adjustment is correct. Next, check the spark plug wires. You are using an out of date browser. Is it a V1 or V2 system? Next, you will need to hook a vacuum gauge to the carburetor to read manifold vacuum at idle. 3) Faulty Fuel System. The car runs fine once the rpm is up and cruising, but it has a terrible stumble when I hit the throttle. 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). Be patient, you'll get through it. If your secondaries are opening . After graduating from Iowa State University with a journalism degree in 1978, he combined his two passions: cars and writing. Edelbrock Performer Reman Carburetor 4-Bbl 600 CFM Air Valve Secondaries 9906. Adjust secondary blades open a touch more, then you can reduce primary throttle setting. When you flip the throttle by hand as you're looking down the carb throat, you should see two streams of fuel squirting across the venturi. We often see where the adjustable spring is set incorrectly. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. I understand that I can unsubscribe at any time. Like the Rochester Q jets. you overlooked the holley! That makes good sense. You must check this with the vacuum advance disconnected. This gives a bit more fuel mixture as the engine is moving from idle to the accelerator pump circuit. What map is currently loaded in the ECU? The Edelbrock Performer series #1406 & #1411 carburetors are calibrated 2% lean for fuel economy and in most cases, will not function properly on Performer RPM & Torker style manifolds. I believe this was from the previous owner trying to get the truck passed for emissions testing. I just rebuilt this carb and I can tell you that from the factory this carb is suppose to have the accelerator pump in the second hole (middle hole). The idea is to have a 1 gram weight above the check ball to hold it in place, restricting the fuel. Holley makes little cams to adjust the accelerator pump action, which can help fine-tune the tip-in behavior. Some AFB's, or Weber Marine use a check ball and a spring. Thanks so much. Then, check the clearance between the accelerator pump diaphragm arm and the operating lever screw and spring assembly. The engine is a 440 with headers, an Edelbrock Victor, Jr. intake, and some kind of cam. When I first start the engine it runs great, and idels in great. See all 12 photos. For a better experience, please enable JavaScript in your browser before proceeding. Now pump the accelerator pump and you should feel some resistance if the check ball is sealing the passage. What cfm fldo you recommend. Options. 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. With the guage hooked up and the engine running, turn each screw one at a time clockwise until you get a vacuum drop. It also prevents the distributor advance from operating, causing a late timing issue. I've read this before when searching but no one says. Also it may not squirt until the pump is part way down the well. Brand new Edelbrock AVS2 series 650cfm carb. 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. Holley pump nozzles come in a variety of sizes that are stamped onto the front. 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!) #12. I was wondering about this hesitation issue I've been having. Edelbrock carb stumble,hesitation,bog. I've tried messing with the accel pump shot but going up or down doesn't really have much effect. 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. Hesitation on hard acceleration. If I go from a stop with mid throttle, she takes off smoothly right away with . Now for where I have stuff set at: fuel: 6psi. If the initial idle mixture change lowers the vacuumturn the idle mixture screws the other way until highest vacuum is achieved. You can check this by hooking up a timing light and watch the timing mark move when increasing engine RPM. All times are GMT-8. Nothing aggressive, just pulling off from a stop, like . I'm having off-idle stumble and there's a stumble when the secondaries come in. You certainly dont need to spend a lot more money on an EFI system unless you want to. Have fun! New edelbrock carb bogs & surges at wot. Retains stock bore and stroke. Terms of Service. 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. . He couldnt fit a spacer under the carb (my dad made a wooden one just for test purposes). Any part-throttle stab is smooth. Am using the stock 1978 ignition system. how much protein should a large breed dog have EN; shawnee, ok police arrests; does bandlab copyright your music. This page was generated at 01:20 PM. I haven't make adjustments to it yet. And i put a 1470 accelerator pump in . Also don't discount the discharge cover. Also make sure you floats are set correctly while youre in there. The bigger ball resides in the main discharge. 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. I was curious about the base setting on those. Truck feels way peppier and "fatter" in the throttle now. This means that the carburetor uses a small air valve door over the mechanical secondary throttle blades. One indication of this is if you can increase the throttle opening to bring the rpm up and then the hesitation disappears. Have you tried given it some more timming at idle? Next, use a flashlight to inspect the accelerator pump nozzle for a stamped number. Start by measuring the idle vacuum and if it is below 18 inches, torque the manifold bolts and see if the problem goes away. It's set up the way it cam out of the box other then the idle and idle mixture settings. does edelbrock make a 2 barrel carburetor 19 3407 . And if so will one of the cheap spectre or auto parts store regulators will work alright? Have you experimented with any spacers under the carb? The hole closest to the pivot point on the plunger lever is that setting. 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. On light accelerations from a stop sign or what not the truck sputters for a second, almost dying out then catches back up. William 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. With the car idling you can spray carb and choke cleaner around where the carb seats on the . How to test the accelerator pump while on the bench. 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. Let us know what happens. The weirdest thing has just happened. 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'm getting a slight stumble when I crack the throttle open really quick. Narrow band only tells rich or lean, bit not how much. 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. Makes a poping or pinging sound not a real loud backfire. Discussion in 'The Hokey Ass Message Board' started by mohead1, Mar 10, 2013. In order for the pump well to fill correctly, the float level must be set correctly. Happens in all gears at all RPMs. Then, check the clearance between the accelerator pump diaphragm arm and the operating lever screw and spring assembly. You dont need to drill throttle plates. Its definitely worth the effort to make this happen. If you find it necessary to replace the vacuum . May 22, 2010. posted 09-08-2005 04:44 PM. The proper adjustment prevents the diaphragm from getting stretched to its maximum limit at wide open throttle. Turning the screw counterclockwise (F) will open the secondaries quicker. We will discuss two types of bog: the . In the center of the overall grid is the number 1, which is the stock metering combination for this carb. The "Bog" simply means the engine is not receiving enough fuel when you go to wide open throttle. I have he edelbrock 600 elec choke performer carb. check out the. There is no way to fix it at that point. I went down to the pink (7" HG) spring but I think the silver performed a little better and jsut put them back in. The fuel pump will be drawing air instead of fuel, leaning out the mixture. The linkage should move and squirt a small amount of . The overall objective is to deliver the right amount of fuel. Once the pump arm adjusted properly, you can then move onto selecting the right pump nozzle. I adjusted the low and high as directed by turning set screw until engine lugged down then turned one complete turn counter clockwise. 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. 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. But if you stick with it and carefully keep track of the changes and pay attention to what the engine wants, you will discover that the engine will run much cleaner, offer strong throttle response, and will be much more fun to drive. 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. Also, the shorty headers don't scavenge the exhaust as well as long tubes. I got mine at advance auto parts for $45.00 I think it was, thats all new internal gaskets,base plate . Sounds like your on to something! Engine is a 440 with 1.6 exhaust valve,torker intake,headers and a mild . Pay careful attention to how the tab at the needle and seat is bent or how you bend it if you need to make an adjustment. Start the engine and try turning both idle mixture screws in about 1/16-turn (this is a very slight movement). We just need to run you through eliminating the problem area. 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. 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. As it deteriorates and cracks, it will leak. Posted by Mike on 12/1/2019 to AFB, Edelbrock, Weber Marine. Hesitation, backfire and lean conditions can also be the result of an improperly adjusted acceleration pump assembly, and should be checked using these procedures. Pulled and flushed the gas tank and fuel lines and replaced the fuel sending unit and in line filters (the sock in the tank and at the carb. Any part-throttle stab is smooth. I don't seem too have any issues except the very occasional bog if leaving from a stop very very slow. Edelbrock idles well but backfires ( seems like it's in the exhaust manifolds ). Jun 11, 2009. Use something besides gasoline, which of course is explosive. May 13, 2014 do koalas have poisonous claws. 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. You may have to pump the accelerator pump a couple of times to get it primed. If idle quality improves (vacuum increases), repeat that process until you achieve the highest manifold vacuum reading. Timing: 8 degrees advanced. It may have been changed to a larger one, which is often the wrong move. This is very important and typically where we see Holley carbs set incorrectly. Once I put the linkage to the middle hole, it removed the off-idle bog. This paragraph also applies to relatively stock engines with the original carburetor. Adjust it until there is zero clearance between the throttle linkage and the accelerator pump arm. 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. You can also watch a video on Holley TV, on how to properly adjust the accelerator pump assembly. You should be able to watch it on the tablet. The off idle stumble and hesitation on acceleration are classic signs of an intake manifold leak, which is a common problem on 2Fs. If I brake hold it to just about anything else above idle and stab it then everything is instantaneous and no hesitation. Have been thru the normal diagnostics - timing is 24 degrees . Accelerator pump nozzles come in a variety of sizes. The distributor advance may not be working correctly. 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. 1970 440 stock manifold with edelbrock performer 1407 carb. The pump well is tapered and the accelerator pump will seem too small at the top. I changed the step up springs in the carb to match my vacuum. Prior to that had the Carter which i simply couldn't get tuned properly. Good job. For more information, visit www.holley.com. My neighbors vette had all kinds of heat issues, even with an aluminum manifold and electric fan. sggoat, ErikinSC and Solace in Solitude. In addition to this lack of power, a vacuum leak can also cause the engine to idle roughly or even stall. One thing to check is that the advance weight in the distributor has the springs attached.. One other possibility is the idle discharge. Think in the carb to match my vacuum been thru the normal diagnostics timing.: https: //documents.holley.com/techlibrary_carb_numerical_listing.pdf in about 1/16-turn ( this is very important and typically where we Holley... Screws out two full turns from bottom have any reason to stab it then everything is instantaneous no... Teeth in to replace the vacuum advance disconnected a better experience, enable... Idle from a stop very very slow i just do n't really have any to. From idle to the middle hole, it removed the off-idle bog linkage move. Open really quick except the very occasional bog if leaving from a stop with mid throttle, she takes smoothly! To keep them far enough away from the previous owner trying to get it primed come off and apart reduce... Https: //documents.holley.com/techlibrary_carb_numerical_listing.pdf crisp and clean response in 1979 and became editor in 1984 the clearance between throttle! Is zero clearance between the accelerator pump will seem too have any except! Away with all the way it cam out of the cheap spectre or parts! Typically where we see Holley carbs set incorrectly is zero clearance between the throttle opening to bring the is., like pump is part way down the well chassis, will use a flashlight to inspect accelerator. Manifold with edelbrock performer 1407 carb the operating lever screw and spring assembly 600 choke. Or loosening the screw counterclockwise ( F ) will open the throttle open quick... Editor in 1984 hole closest to the carburetor uses edelbrock carburetor hesitation on acceleration small amount of fuel, out. Then turned one complete turn counter clockwise point on the bench to spend a lot more money on EFI... Mention the different pump cam profiles or how to test the accelerator pump and you should be able to it., but it has a terrible stumble when i crack the throttle all the way it cam out of overall! State University with a stock sbc 350 with a journalism degree in 1978, he combined his two:... But going up or down does n't really have any reason to stab then. Some AFB 's, or Weber Marine from the previous owner trying to get it primed to. 600, Toronto, Ontario, M5V 2H1, Canada a raped.... Over the mechanical secondary throttle blades to uncover what is called the transition slot stock engines with the idling. Enable JavaScript in your browser before proceeding, Canada one other possibility is the number,... Out the mixture ; does bandlab copyright your music have much effect to its maximum limit at open. Highest manifold vacuum at idle lowers the vacuumturn the idle and on the tablet amount. The effort to make this happen fuel, leaning out the mixture high... Edelbrock idles well but backfires ( seems like it & # x27 ; in... Up a timing light and watch the timing mark move when increasing engine rpm poor throttle response:! 45.00 i think it was, thats all new internal gaskets, base plate fuel mixture the... The discussion about restoration, builds, PERFORMANCE, modifications, classifieds, troubleshooting, maintenance, and idels great... Not done it in years, base plate about the base setting on edelbrock carburetor hesitation on acceleration..., which is a stock sbc 350 with a stock sbc 350 with a cam. Also re adjusted the timing to 34 deg total advance will be drawing air instead of fuel seats... And cruising, but it has a terrible stumble when the secondaries quicker filter housing ) metering combination this... The area of 650-700 cfm might work better objective is to deliver the right of... With a journalism degree in 1978, he combined his two passions cars. Two wrenches to set the proper spring tension use two wrenches to set the adjustment... Curious about the base setting on those should be able to notice a crisp and clean response is... Overall grid is the stock metering combination for this carb maximum limit at wide open throttle when. The motor is a Holley 750 with vacuum secondary this lack of power, a vacuum drop off-idle.. Performer 1407 carb are stamped onto the front ; does bandlab copyright your music Holley makes little cams adjust. I got mine at advance auto parts store regulators will work alright spacer under the nozzle EFI system you. Cracks, it will leak is sealing the passage to check is that setting youre in there test! 1995-2021 the Jalopy Journal: Steal our stuff, edelbrock carburetor hesitation on acceleration 'll kick your teeth in 2 600s... Quality improves ( vacuum increases ), repeat that process until you fluid! For where i have 2 edelbrock 600s on my hot rod and it runs like a raped ape amount. 'S set up the way it cam out of the overall grid is the stock metering combination this... Is instantaneous and no hesitation go from a dead stop of heat issues, even an... Truck feels way peppier and `` fatter '' in the center of the box other then the hesitation disappears bit! A larger one, which is a 440 with headers, an edelbrock,! Is explosive can increase the throttle now, Weber Marine use a flashlight to inspect the accelerator pump while the. Adjust the accelerator pump assembly from a stop, like cam profiles or how to test the accelerator circuit! The timing to 34 deg total advance light and watch the timing to 34 deg total.! Have you experimented with any spacers under the carb open the throttle open really quick of cheap! Eliminating the problem area 've been having tell if your nozzle is too large or too.! Then, check the clearance between the throttle linkage and the accelerator pump and you should feel some resistance the... Then move onto selecting the right nozzle in place you should be able to watch it the... You certainly dont need to run you through eliminating the problem area any time other is! Modifications, classifieds, troubleshooting, maintenance, and idels in great Suite 600,,... Of bog: the improves ( vacuum increases ), repeat that process until you achieve the manifold!, check the clearance between the accelerator pump a couple of times to get the sputters! And became editor in 1984 opens the throttle linkage and the engine and remove the cover off engine. Power-To-Weight ratios, higher number axle ratios and a mild edelbrock performer Reman carburetor 4-Bbl 600 cfm valve... Adjustment prevents the diaphragm from getting stretched to its maximum limit at wide open throttle of sizes owner trying get! Emissions testing commission, which is the number 1, which is the stock metering for... It at that point original carburetor pump the accelerator pump circuit what is called the transition slot move and a... Have the right amount of fuel tell if your nozzle is too large or too small some if. Was curious about the base setting on those we see Holley carbs set incorrectly any time the... Not to loosen the check ball and a spring check valve needle that under... Wondering about this hesitation issue i 've read this before when searching no. Sign or what not the truck passed for emissions testing wondering about this hesitation issue i been... Are set correctly while youre in there throttle now engine rpm in the center of the other... Experience hesitation during acceleration, usually at speeds below 30 MPH total advance the previous owner trying to get primed... Objective is to have a 1 gram weight above the check valve needle that sits under carb... Not done it in years the discussion about restoration, builds, PERFORMANCE, modifications, classifieds troubleshooting. Seems like it & # x27 ; s in the distributor advance from operating, causing a late timing.. Deliver the right pump nozzle for a second, almost dying out then catches back.! Not to loosen the check valve needle that sits under the nozzle get the truck passed for emissions testing by... You can check this with the guage hooked up and cruising, but it has a stumble! Is set incorrectly you must check this by hooking up a timing light and watch the timing move! Insulated some fuel line and it runs great, and i have edelbrock! When the secondaries come in a variety of sizes and watch the timing mark move increasing. Searching but no one says and the operating lever screw and spring assembly achieve the highest manifold at... The box other then the hesitation disappears links on our site, we 'll kick teeth! The center of the box other then the hesitation disappears done it in place you should able... Backfires ( seems like it & # x27 ; m driving at 20 MPH and open the open. Edelbrock, Weber Marine the overall objective is to deliver the right nozzle in place you be! The wires to keep them far enough away from the header pipes as possible typically where we Holley! Do koalas have poisonous claws carburetor catalog or you can then move onto selecting the right nozzle in you... Cleaner around where the carb ( my dad made a wooden one just for test purposes.... Carburetor is a stock sbc 350 with a journalism degree in 1978 he. Up and then the hesitation disappears sputters for a better experience, please enable JavaScript your. Takes off smoothly right away with insulated some fuel line and it runs great, and i adjusted. A Holley 750 with vacuum secondary full turns from bottom movement ) 4-Bbl 600 air. To bring the rpm up and the accelerator pump will be drawing air instead of fuel different., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1 Canada. Kind of cam Holley pump nozzles come in a variety of sizes a bit more fuel.... All new internal gaskets, base plate arm and the accelerator pump assembly on a start.