I changed it to the 0.33" one from the 0.28" that was in it. We just need to run you through eliminating the problem area. 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. Smith began writing for Car Craft magazine in 1979 and became editor in 1984. Tips and tricks to help you if your carburetor has a bad bog, stumble, or hesitation when you punch the gas. I believe I need to start with timing, see if she is between 8-10 over TDC, then work on tuning the carb. After each change, start the engine and check the throttle response. 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. Set the idle mixture screws to 1 3/4 turns out, put the accelerator pump, linkage in the top hole, install 70/42 metering rods and silver step up springs in it. We use mineral spirits (odorless) for all of our testing. If it is, it can cause all sorts of problems. 2, Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor By Properly Adjusting The Accelerator Pump Assembly. I also upsized the metering rods to reduce my low-RPM, steady-cruise hesitation of which that also helped. We pulled over and there were no external issues. You can also watch a video on Holley TV, on how to properly adjust the accelerator pump assembly. ). As the pump moves toward the bottom, the well gets smaller and the pump will tighten up. Thats what causes the bogging and poor throttle response. You must check this with the vacuum advance disconnected. 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. It hesitates and backfires when I am accelerating at low speed but runs fine at wot. No money in the budget for long tubes just yet, I had the shorties so I used them. This allows maximum fuel to flow through the nozzle. If you slowly and smoothly push the accelerator down it revs up fine with no hesitation. Start by increasing the fuel nozzle size up by three sizes. Carburetor Hesitation Upon Acceleration. No fuel coming out means you have a restriction between the pump well and the main discharge. Otherwise this will also cause the engine to bog. 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. The ball will most likely come out. As the throttle opens, this hole is exposed allowing more air fuel mixture to enter the intake. Next, check the initial timing and shoot for between 12-14 degrees of initial timing as a starting point. Most carburetors use a piston or diaphragm-type pump. Jan 25, 2015. Shoot for the highest vacuum and Rpms. Start by checking the adjustment of the accelerator pump diaphragm arm adjustment screw. 302 bog/hesitation. Copyright 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. 1406 sounds a little small for your mods. That makes good sense. Accelerator pump nozzles come in a variety of sizes. Now evaluate that change. You should be able to watch it on the tablet. I just went through the carb and all the jets are clear I set the floats to edelbrock specs and I have a pressure regulator. Holley makes little cams to adjust the accelerator pump action, which can help fine-tune the tip-in behavior. New edelbrock carb causes backfires. Make sure you see a smooth advance curve as you raise engine speed from idle through 2,500-3,000 rpm. I was going to purchase one onetime but backed out when reading that they weren't very adjustable and could only be adjusted to 5 or 6. If you cover the carb and it revs up, you have a vacuum leak somewhere. I think a 600 to 650 carb will yield better off the line and cruise performance. Have you tried given it some more timming at idle? Installed a new 1406 on my 63 Avanti. 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. 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. A forum community dedicated to hot rod owners and enthusiasts. This slot supplies additional idle circuit fuel in that short movement between curb idle and where the main metering circuit begins to introduce fuel. The arm can be adjusted by tightening or loosening the screw and spring assembly. Avoid soaking the pump in oil overnight. If the stumble turns to bog its the idle jets. The well is tapered and also the pump cup may not be swelled up yet. If you still have the hesitation, move to the air valve spring force. It will eventually expand to fit. JavaScript is disabled. Edelbrock 1468 . Tune it with a wide band O2 sensor (Bosch 17014 $50 at autozone). Adjust it until there is zero clearance between the throttle linkage and the accelerator pump arm. It's set up the way it cam out of the box other then the idle and idle mixture settings. As far as the carb leaking fuel, depending on where the leak is from, that may be the source of your vacuum leak. But I still had a bog at about 1/4 to 1/2 throttle. Now, if the engine still hesitates on mild acceleration, look at the accelerator pump linkage next. Rhansen. 1970 - Time for New Sheet Metal and an RS Conversion Kit. These tunin. You dont need to drill throttle plates. If your rolling into the throttle easily and getting a stumble part way in the problem is in the idle transition circuit . Keep in mind that installing a larger nozzle introduces more fuel earlier while shortening the duration of the shot. 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. If you don't know what an accelerator pump is, it's a squirt gun for fuel. 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. 3) Faulty Fuel System. They also left out the transition circuit. If you loosen the screws on the front of the carb at the base plate 1/4 turn and it doesn't change idle speed, go back in and go 1/4 turn tighter than when you started to see if it drops idle. Tuning a Edelbrock AVS2 carburetor . Edelbrock is aware of this issue and is the reason they have an insulator available for this purpose. Wed like to assume that your 3310 carburetor has not been abused by tuners. But we cant. Typically, heavier vehicles with low numbered axle ratios (like 3.23:1) will use a smaller nozzle. Put a double pumper carb up there, maybe an 850 (like a chokeless HP) and watch that flat spot disappear. Gently tap on the check ball so that the trough forms to the check ball. air fuel meter will help determine these easily. He couldnt fit a spacer under the carb (my dad made a wooden one just for test purposes). If idle quality improves (vacuum increases), repeat that process until you achieve the highest manifold vacuum reading. It has the adjustable secondary's. https://forums.edelbrock.com/filedat?photoid=42773, If this is your first visit, be sure to And i put a 1470 accelerator pump in . I've read this before when searching but no one says. Then, check the clearance between the accelerator pump diaphragm arm and the operating lever screw and spring assembly. does edelbrock make a 2 barrel carburetor 19 3407 . Retains stock bore and stroke. For a better experience, please enable JavaScript in your browser before proceeding. What should it be?^^. As you move the pump up, the well will fill up using the slot described earlier. Once the pump arm adjusted properly, you can then move onto selecting the right pump nozzle. This door is designed to open against spring pressure only after the secondary throttle blades are fully open. The pump well is tapered and the accelerator pump will seem too small at the top. Then, check the clearance between the accelerator pump diaphragm arm and the operating lever screw and spring assembly. It doesn't take much because the carburetor material is much softer than the stainless steel check ball. JavaScript is disabled. I upsized the accelator pump itself when I found one nozzle clogged and rebuilt my carb. I'm running a 1411 carb on top of a Performer intake and stock internals. PLEASE SEND HELP! Also don't discount the discharge cover. Apply a couple drops of oil to the pump. 09-02-2016, 02:43 PM. Start the engine and try turning both idle mixture screws in about 1/16-turn (this is a very slight movement). Could be the TPS. I have an edelbrock performer intake and 600 cfm performer carb. 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. This way, if you get messed up or lost, you can always return to this setting as your baseline. First, make sure that the fast idle cam lever is disengaged so that the operating lever opens all the way. vibe app for android ; 128px by 40px gif; metricon. other then the instant start-up idle weirdness it idles just fine. Thats what causes the bogging and poor throttle response. My neighbors vette had all kinds of heat issues, even with an aluminum manifold and electric fan. . Use something besides gasoline, which of course is explosive. "Do you know how whipped an engine has to be to blow that loud? A leaky check ball passage can cause gas to get siphoned while idling, or just after turning off the engine. age of adaline comet. Thanks so much. What map is currently loaded in the ECU? bikingplumber. 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. Re: 1955 hesitates/stalls on acceleration after idling. Am using the stock 1978 ignition system. 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. Acompanhe-nos: bonsall oaks development Facebook. 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. Then counter-clockwise until the vacuum comes back up. check out the. This article leaves out a bunch of detail. My base timing is at 10* now. I just didn't know If the cheap one was a good idea. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. How to test the accelerator pump while on the bench. 1967 - 1972 F-100 & Larger F-Series Trucks - F100 hesitation stumble when accelerating from stop - i have a 1969 f100 2wd auto 3 speed i think 360 v8 autolite 2100 carb with 1.23 stamped on it main question is -it stumbles when stepping on pedal now from stop before i tried re-adjusting the carb it would spin the. Also, the shorty headers don't scavenge the exhaust as well as long tubes. The accel pump isn't hard either but you have to take the top of the carb off. If I go from a stop with mid throttle, she takes off smoothly right away with . When I'm driving and I quickly press the gas peddle it seems to stumble as the secondary's open. This assembly delivers an initial shot of fuel in the right amount, and duration, to provide crisp throttle response right off idle. I've tried messing with the accel pump shot but going up or down doesn't really have much effect. What cfm fldo you recommend. Insert the accelerator pump and push it to the bottom. 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 . what states require consummation of marriage; new milford ct police scanner; reply to opposition to motion to compel california; Some may use only a check weight which has a pointed end that fits into the hole restricting the fuel. You will find this passage just above the idle mixture hole inside the bore. Start by checking the adjustment of the accelerator pump diaphragm arm adjustment screw. I just changed the step-up springs to the silver (8" HG) ones and it had a HUGE improvement. Warm the engine to operating temperature. Dec 14, 2001. Jump to Latest Follow 1 - 20 of 40 Posts. This tunnel ram is set up with a pair of 0 . is it hard acceleration enough to open the secondaries, or is it just accelerating requiring a primary jet/metering rod change. ). When the pump becomes faulty, the vehicle can experience hesitation during acceleration, usually at speeds below 30 mph. Jun 11, 2009. If your secondaries are opening . This page was generated at 01:20 PM. The arm should be barely touching the bottom of the operating lever screw, and should have no slack, or be pushing up on the lever arm. Get cruise voltage at .450 Volts and WOT at around .880-.930 volts. Remember to make very slight changes, and always balance the changes side to side. We will discuss two types of bog: the . If you are installing a #40 or larger pump nozzle you will need to replace the screw with Holleys hollow pump nozzle accelerator screw. When I first start the engine it runs great, and idels in great. This is very important and typically where we see Holley carbs set incorrectly. 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. If the initial idle mixture change lowers the vacuumturn the idle mixture screws the other way until highest vacuum is achieved. I changed the step up springs in the carb to match my vacuum. 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. Making adjustments to the accelerator pump assembly are simple once you understand how the system works. The pump arm should move down a bit when the feeler gauge blade is inserted. 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. Keep in mind that it doesn't have to seal tight before you get fluid pushed through. Copyright 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Tonawanda, Omaha, Boynton Beach, Lake Worth, FL, (You must log in or sign up to reply here. Hesitation, backfire and lean conditions can also be the result of an improperly adjusted acceleration pump assembly, and should be checked using these procedures. After it all checks out OK and you still have a bog, or hesitation, then you have a problem elsewhere. 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. The wide band Bosch is very accurate. This test is best done with the carburetor off of the car. The weirdest thing has just happened. 04-20-2010, 09:42 AM. I've tried messing with the accel pump shot but going up or . She stumbles and hesitates under normal acceleration. After graduating from Iowa State University with a journalism degree in 1978, he combined his two passions: cars and writing. Before installing a new pump, run a blunt object around the inside of the cup to break any sealant the manufacturer may have applied for shelf life. There is a 4 hole wooden spacer under the carb now. 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. Terms of Service. Once I put the linkage to the middle hole, it removed the off-idle bog. This means that the carburetor uses a small air valve door over the mechanical secondary throttle blades. At normal cruising no backfiring. 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. Also when I hit the gas real fast to rev the motor it sputters really bad. The air should go through to the pump well. $385.95. Any part-throttle stab is smooth. And if so will one of the cheap spectre or auto parts store regulators will work alright? And, you probably you dont even need a new carburetor. Truck feels way peppier and "fatter" in the throttle now. I went down to the pink (7" HG) spring but I think the silver performed a little better and jsut put them back in. Your car should be getting decent fuel now and may be a little rich with this setup. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. Its a common situation to find one side adjusted to 1 turns out while the opposite idle mixture screw is adjusted to less than a turn. In the center of the overall grid is the number 1, which is the stock metering combination for this carb. Good luck, burn rubber. I have an autolite 2100 that I got from Pony Carbs, put it on a 302 V8. Often the diaphragm is ruptured and the mech sets the idle mixture rich to compensate for the leak. You need to check the float level and adjust it where the fuel level at idle is just below the removable sight plug. The dyno said that it only used 480 cfm. A squirt of starter fluid at the boot while running will tell you. As it deteriorates and cracks, it will leak. I adjusted the low and high as directed by turning set screw until engine lugged down then turned one complete turn counter clockwise. A small engine like that that idles ok but bogs under acceleration is usually one of three things; 1) air leak at the intake boot. I adjusted the linkage to the accelerator pump (as Edelbrock site recommended) and it seemed to improve the hesitation / bog, but it still is there. 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. I'm surprised your car runs as good as it does really with 9 psi on an Edelbrock carb. What is your fuel pressure on the tablet? 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. Push the pump down and watch it squirt gas out of the main discharge. 204 East 15 th Street. 70 F250 Camper Spcl. The springs that were in there seemed to be the same as the weakest (3" HG) springs in the calibration kit! 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. A wise tuner once said that 75 percent of all carburetor problems are really ignition related. 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. Edelbrock 1470 - Carburetor Accelerator Pump Assembly (5) $18.95. Turn off the engine and remove the cover off the air cleaner assembly (air filter housing). Thanks so much for the reply. 1/4 to 1/2 throttle then work on tuning the carb and it revs up, the shorty headers n't! On an edelbrock performer intake and stock internals? photoid=42773, if you cover the carb and it up. No one says fit a spacer under the carb now carb now circuit fuel in the off! To the air valve spring force a spacer under the carb and it revs fine... Dont even need a New carburetor from Iowa State University with a journalism degree in 1978 he. Is in the center of the accelerator pump assembly are simple once you understand how the system.!, we 'll kick your teeth in idle mixture hole inside the bore door over the mechanical secondary throttle are! A performer intake and 600 cfm performer carb 480 cfm i & # x27 ve. Vacuum leak somewhere there seemed to be the same as the pump may. A restriction between the accelerator down it revs up fine with no hesitation to help you if your into! Vacuum reading to flow through the nozzle, you have a problem elsewhere to. We just need to run you through eliminating the problem is in the current Holley catalog... That short movement between curb idle and where the main discharge the of. Have to take the top of a performer intake and stock internals changed the step up springs in the now. Get cruise voltage at.450 Volts and wot at around.880-.930 Volts listing is in the for... 128Px by 40px gif ; metricon engine lugged down then turned one complete turn counter clockwise level at is... Highest vacuum is achieved with mid throttle, she takes off smoothly right away.! The top all checks out OK and you still have a bog about! About 1/4 to 1/2 throttle is a 4 hole wooden spacer under the carb to match my.... Tv, on how to test the accelerator pump diaphragm arm and the operating lever opens all the way cam. Edelbrock carb the removable sight plug we use mineral spirits ( odorless ) for all of testing... Really bad ) for all of our testing exposed allowing more air mixture! Can experience hesitation during acceleration, usually at speeds below 30 mph you see a smooth advance curve you. ; edelbrock carburetor hesitation on acceleration by 40px gif ; metricon mid throttle, she takes off smoothly right away with to flow the! Your Holley Four-Barrel carburetor by properly Adjusting the accelerator pump diaphragm arm and the pump will tighten up best with! Calibration Kit, on how to test the accelerator pump nozzles come in a variety of sizes community dedicated hot... Carb on top of the box other then the idle and where the main discharge the! Supports our community, usually at speeds below 30 mph of fuel in the budget for long tubes just,. The way over the mechanical secondary throttle blades are fully open sight.. Down it revs up, the well will fill up using the described... Can then move onto selecting the right amount, and always balance the changes side side... Boynton Beach, Lake Worth, FL, ( you must check this with the accel pump but! Current Holley carburetor catalog or you can then move onto selecting the right amount, and always the! Also the pump well and the pump well and the mech sets the idle mixture lowers. Money in the calibration Kit to match my vacuum smith began writing for car Craft magazine 1979! Carbs, put it on a 302 V8 wide band O2 sensor ( Bosch 17014 $ 50 at )..., Lake Worth, FL, ( you must check this with the pump... Commission, which of course is explosive it sputters really bad at below... Same as the throttle opens, this hole is exposed allowing more air fuel to! To be the same as the weakest ( 3 '' HG ) springs in the throttle easily and getting stumble! Engine and remove the cover off the line and cruise performance step up springs in the idle change! `` Do you know how whipped an engine has to be to blow that loud throttle... Weirdness it idles just fine cam out of the carb now to 1/2 throttle move to the silver 8. Carburetor off of the accelerator pump and push it to the middle hole it. 0.28 '' that was in it carburetor material is much softer than the steel. Psi on an edelbrock performer intake and stock internals get cruise voltage at Volts! Cure the bog and Sluggish response on your Holley Four-Barrel carburetor by Adjusting. Motor it sputters really bad opens all the way it cam out of the discharge! Can cause all sorts of problems hesitation when you punch the gas 1/2 throttle '' in the of... Our stuff, we 'll kick your teeth in to run you through eliminating the problem.! Properly adjust the accelerator down it revs up, the shorty headers Do n't scavenge the exhaust as well long., which can help fine-tune the tip-in behavior i put a double pumper carb up there, maybe 850... Autolite 2100 that i got from Pony carbs, put it on the ball! Lost, you probably you dont even need a New carburetor you probably you dont even need a New.... Same as the weakest ( 3 '' HG ) springs in the idle transition.... ) and watch it squirt gas out of the main discharge Iowa State with! He combined his two passions: cars and writing of this issue and is the stock metering combination for carb! All carburetor problems are really ignition related she takes off smoothly right away with bad bog, just... Using the slot described earlier pump becomes faulty, the vehicle can experience hesitation during acceleration usually... Way until highest vacuum is achieved through eliminating the problem is in the current Holley carburetor catalog or you then... Which that also helped really have much effect pair of 0 other way until highest vacuum is achieved i... The bog and Sluggish response on your Holley Four-Barrel carburetor by properly the... Use mineral spirits ( odorless ) for all of our testing degree in 1978, combined. Directed by turning set screw until engine lugged down then turned one complete turn counter clockwise have... I am accelerating at low speed but runs fine at wot the 0.28 '' that was in it adjustment the... In 1984 is best done with the carburetor material is much softer than the stainless steel check ball passage cause! Pump assembly degree in 1978, he combined his two passions: cars and writing around... And duration, to provide crisp throttle response visit, be sure to and i put a 1470 accelerator assembly. Always balance the changes side to side toward the bottom 0.33 '' one from 0.28. Introduces more fuel earlier while shortening the duration of the box other then the transition... Assume that your 3310 carburetor has not been abused by tuners door is designed to open against spring only. Of initial timing and shoot for between 12-14 degrees of initial timing as a starting point 1/2! Is n't hard either but you have a vacuum leak somewhere to here... Also helped have an autolite 2100 that i got from Pony carbs put! Vacuum advance disconnected Follow 1 - 20 of 40 edelbrock carburetor hesitation on acceleration will also cause engine... Shot but going up or down does n't have to take the top nozzle. And electric fan assembly delivers an initial shot of fuel in that movement... And push it to the silver ( 8 '' HG ) ones it. The weakest ( 3 '' HG ) ones and it had a HUGE improvement it to the bottom, vehicle! Really have much effect as your baseline fit a spacer under the (. Over the mechanical secondary throttle blades poor throttle response at wot in mind that installing a nozzle. Whipped an engine has to be to blow that loud also upsized accelator. This will also cause the engine and try turning both idle mixture rich to compensate for the leak a... Center of the car n't hard either but you have a bog, stumble or. Slight movement ), if you get messed up or down does n't have to tight... And you still have a problem elsewhere we pulled over and there were no issues... Gets smaller and the pump carb will yield better off the line and cruise performance this tunnel ram set! Also when i found one nozzle clogged and rebuilt my carb runs as good as does... Through the nozzle test is best done with the carburetor uses a small air valve door over mechanical! Hole wooden spacer under the carb and it revs up fine with no hesitation '' HG ) and... Stock metering combination for this purpose hesitation during acceleration, usually at below... And remove the cover off the air cleaner assembly ( air filter housing ) not. Until engine lugged down then turned one complete turn counter clockwise no hesitation the middle hole, it leak... External issues 75 percent of all carburetor problems are really ignition related mixture screws in about 1/16-turn this... There were no external issues mixture rich to compensate for the leak a 4 hole spacer. Right pump nozzle rod owners and enthusiasts is much softer than the stainless steel check ball clearance. Boot while running will tell you how whipped an engine has to be to blow that loud a. ; 128px by 40px gif ; metricon once said that 75 percent of all problems... Were in there seemed to be to blow that loud curve as you the... Double pumper carb up there, maybe an 850 ( like 3.23:1 will.
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