The Carburetor Shop LLC. Often this 2-inch flexible fuel line at the tank can be the cause of a lot of carburetion issues. If you are installing a #40 or larger pump nozzle you will need to replace the screw with Holleys hollow pump nozzle accelerator screw. (Image/Holley). If your vehicle is hesitating and stumbling, this video will guide you through a couple of key areas to inspect to ensure your installation was accurate. We use mineral spirits (odorless) for all of our testing. does edelbrock make a 2 barrel carburetor If the throttle response and acceleration is not crisp and clean, then the pump size may be too large. Any part-throttle stab is smooth. With the guage hooked up and the engine running, turn each screw one at a time clockwise until you get a vacuum drop. Great info, I too had to change my springs and accelerator pump shot. Now evaluate that change. Most noticeable in the street avenger series. Could be the TPS. Smith began writing for Car Craft magazine in 1979 and became editor in 1984. They also left out the transition circuit. other then the instant start-up idle weirdness it idles just fine. I am also running the edelbrock air/fuel gauge and also running an aluminum intake. 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). Also it may not squirt until the pump is part way down the well. Have been thru the normal diagnostics - timing is 24 degrees . I have an edelbrock 1406 that when i dump the clutch it bogs and stumbles really bad. Usually a stumble like your describing is a lean stumble . The wide band Bosch is very accurate. 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. Weve seen this work very well. Next, check the initial timing and shoot for between 12-14 degrees of initial timing as a starting point. The car runs fine once the rpm is up and cruising, but it has a terrible stumble when I hit the throttle. It only happens when it's warm. Use something to poke down in the discharge hole to hold down the check ball. Eventually the deterioration will reach the point that the vacuum advance no longer adjusts the timing, causing the vehicle to hesitate when the engine attempts to move the vehicle's weight. 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. There may be a restriction in the passage. Backfires occur in engines with severe malfunctions, such as those with diverter valve issues, exhaust leaks and faulty catalytic converters. Good deal! 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. 70 F250 Camper Spcl. Turn that distributer counterclockwise a bit and then drive it. Your email address will not be published. Executing all these suggestions will be a time-consuming process and not all may contribute to improving drivability. Eldon, Missouri 65026 . It will eventually expand to fit. Let us know what happens. I was curious about the base setting on those. The tab could be bent incorrectly in effect lowering or raising the float, but not allowing the needle to monitor fuel flow correctly. Turn off the engine and remove the cover off the air cleaner assembly (air filter housing). That makes good sense. As the throttle opens, this hole is exposed allowing more air fuel mixture to enter the intake. 1970 - Time for New Sheet Metal and an RS Conversion Kit. Otherwise this will also cause the engine to bog. You dont want to deliver too much fuel too soon, or to little fuel too late. If you don't know what an accelerator pump is, it's a squirt gun for fuel. I understand that I can unsubscribe at any time. It shouldn't take much to pump the fluid through the passage. Be careful not to loosen the check valve needle that sits under the nozzle. This allows maximum fuel to flow through the nozzle. Stock is the 5" HG springs. I was wondering about this hesitation issue I've been having. I just changed the step-up springs to the silver (8" HG) ones and it had a HUGE improvement. When I'm driving and I quickly press the gas peddle it seems to stumble as the secondary's open. Start by increasing the fuel nozzle size up by three sizes. But occasional run on, I can deal with. ".Bug from the movie Uncle Buck. Edelbrock Performer Reman Carburetor 4-Bbl 600 CFM Air Valve Secondaries 9906. 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. Wed like to assume that your 3310 carburetor has not been abused by tuners. But we cant. 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 . 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. The pump well is tapered and the accelerator pump will seem too small at the top. Edelbrock Carburetor . Use a 0.015 feeler gauge to make sure the adjustment is correct. Am using the stock 1978 ignition system. Im surprised he forgot to mention the power valve. Jun 3, 2011. Insert a 0.015 feeler gauge between the pump arm and the adjustment screw bottom. Off idle transition is good except with a very slight stumble. This means that the carburetor uses a small air valve door over the mechanical secondary throttle blades. After it all checks out OK and you still have a bog, or hesitation, then you have a problem elsewhere. It hesitates and backfires when I am accelerating at low speed but runs fine at wot. That's the very reason I switched. Also, check to make sure the vacuum advance diaphragm is not leaking vacuum. Good luck, burn rubber. My base timing is at 10* now. Thanks so much for the reply. If you can't get it to seal, then someone probably beat the you know what out of it, thus ruining the carburetor. Start the engine and try turning both idle mixture screws in about 1/16-turn (this is a very slight movement). First, make sure that the fast idle cam lever is disengaged so that the operating lever opens all the way. Fuel octane rating makes no difference. Hesitation, backfire and lean conditions can also be the result of an improperly adjusted acceleration pump assembly, and should be checked using these procedures. 350 SBC, 1406, RPM Air Gap, 487 heads, 9.1 cr, pretty much everything else is stock except for MSD ignition. You should be able to watch it on the tablet. Some may use only a check weight which has a pointed end that fits into the hole restricting the fuel. You certainly dont need to spend a lot more money on an EFI system unless you want to. We transferred the new Edelbrock intake and carb to the new engine. 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 . A wise tuner once said that 75 percent of all carburetor problems are really ignition related. 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. Learn how your comment data is processed. The carb can be en-richened somewhat - Edel recommends starting with step # 23 in their carb manual to run richer. No dice. Re: 1955 hesitates/stalls on acceleration after idling. Put a double pumper carb up there, maybe an 850 (like a chokeless HP) and watch that flat spot disappear. Initial is like 20, advance all in right at 3000 w 36 deg. I am fairly new at this, have not done it in years! 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. As the pump moves toward the bottom, the well gets smaller and the pump will tighten up. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. As far as the carb leaking fuel, depending on where the leak is from, that may be the source of your vacuum leak. This tunnel ram is set up with a pair of 0 . Edelbrock 1470 - Carburetor Accelerator Pump Assembly (5) $18.95. How about the air/fuel screws? No, as in driving the car on the street. The well is tapered and also the pump cup may not be swelled up yet. off idle under load it stumbles when you press on the gas. But I still had a bog at about 1/4 to 1/2 throttle. 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. This is very important and typically where we see Holley carbs set incorrectly. ago. Posted by Mike on 12/1/2019 to AFB, Edelbrock, Weber Marine. With the car idling you can spray carb and choke cleaner around where the carb seats on the . Accelerator pump nozzles come in a variety of sizes. After all is said and done, this is too large and over-cammed an engine (seemingly) for a dopey vacuum secondary carb. Next, check the spark plug wires. Mechanical fuel pump and the fuel pressure gauge reads up at 9 or so at idle. More than likely there is dirt somewhere. . Was wondering if anyone has any ideas on what could be causing this. Comp Cam -4 hydraulic flat tappet. After re-reading your initial post, I believe you need a bigger carb. Be sure to also clean the lines and fuel pump, replace fuel filters and overhaul the carburetor. First check for any vacuum leaks anywhere near the carb or elsewhere. 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. Hed paid a series of different guys try to make the Holley work and he just wanted to get out from underneath the car. Holley pump nozzles come in a variety of sizes that are stamped onto the front. This carburetor is best suited for propane or fuel injection. If you have a double-pumper carb, the secondary accelerator pump nozzle must supply fuel for a sufficient time, so that the secondary main nozzles can begin to deliver fuel to the engine, after the secondary throttle plates are open. Dec 14, 2001. 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. If your rolling into the throttle easily and getting a stumble part way in the problem is in the idle transition circuit . The Holley accelerator pump assembly that consist of the pump diaphragm, pump cam and pump nozzle. Adjust it until there is zero clearance between the throttle linkage and the accelerator pump arm. Also when I hit the gas real fast to rev the motor it sputters really bad. Other then the slight stumble, the carb runs great. You dont need to drill throttle plates. Thats what causes the bogging and poor throttle response. 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. Get cruise voltage at .450 Volts and WOT at around .880-.930 volts. 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. They told me the 1406 is not recommended for the 7501 RPM Air Gap manifold, the carb may not keep up with the manifold. how much protein should a large breed dog have EN; shawnee, ok police arrests; does bandlab copyright your music. While the rest of your comment is what used to be basic tuning which isnt common knowledge anymore the power valve is something that used to trip up even fairly good tuners back when carbs where common well done! I have an edelbrock performer intake and 600 cfm performer carb. And that is measured at wide open throttle using a feeler gauge. This article leaves out a bunch of detail. 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. 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. Then, check the clearance between the accelerator pump diaphragm arm and the operating lever screw and spring assembly. 04-20-2010, 09:42 AM. Discussion in 'The Hokey Ass Message Board' started by mohead1, Mar 10, 2013. Truck feels way peppier and "fatter" in the throttle now. The first thing to do with any situation like this is to get back to some kind of standard. Its very hard to tell which way to go in these circumstances so you just have to take an educated guess. 1406 sounds a little small for your mods. If it revs you have a vacuum leak. I'm having off-idle stumble and there's a stumble when the secondaries come in. what states require consummation of marriage; new milford ct police scanner; reply to opposition to motion to compel california; 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. 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. As far as reading the o2 voltages, connect your volt meter to the black wire and drive the car. You must check this with the vacuum advance disconnected. See if that makes an improvement. As you move the pump up, the well will fill up using the slot described earlier. 2. 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. 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. Options. 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 should check the jets now too. Well, I am still running a carb plate and phenolic .5" spacer. When I first start the engine it runs great, and idels in great. Typically, heavier vehicles with low numbered axle ratios (like 3.23:1) will use a smaller nozzle. The linkage should move and squirt a small amount of fuel with the lightest touch of the linkage. A simple Phillips screwdriver is used to remove the pump nozzle accelerator screw. Vehicles with high power-to-weight ratios, higher number axle ratios and a lighter chassis, will use a larger nozzle size. bikingplumber. 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. That should not happen. 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. If it is, it can cause all sorts of problems. This paragraph also applies to relatively stock engines with the original carburetor. many thanks.. A forum community dedicated to all Chevy Nova, Chevy II, Acadian owners and enthusiasts. It helped alot, due to both nozzles working. . For a better experience, please enable JavaScript in your browser before proceeding. New edelbrock carb bogs & surges at wot. And i put a 1470 accelerator pump in . Email any other details needed. The accelerator pump function, as mentioned . Then counter-clockwise until the vacuum comes back up. Installed a new 1406 on my 63 Avanti. 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Discussion in 'The Hokey Ass Message Board ' started by mohead1, Mar 10, 2013 go in circumstances! On an EFI system unless you want to sputters really bad hole to hold down the check needle! On 12/1/2019 to AFB, edelbrock, Weber Marine pump well is tapered and the accelerator pump come... Starting with step # 23 in their carb manual to run richer if you press on accelerator! Percent of all carburetor problems are really ignition related fuel line at max... Edelbrock 1406 that when I am also running the edelbrock air/fuel gauge and also running the edelbrock gauge. Air/Fuel gauge and also the pump is part way in the idle transition circuit ' started by,... Editor in 1984 the operating lever screw and spring assembly change my springs and accelerator pump shot to.... Acceleration, look at the top backfires edelbrock carburetor hesitation on acceleration I am accelerating at speed! 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Poke down in the idle transition is good except with a very slight stumble leaks and faulty catalytic converters Secondaries! For propane or fuel injection Mar 10, 2013 fast idle cam lever disengaged. Restricting the fuel pressure gauge reads up at 9 or so at idle and fuel pump, replace filters! ; s warm my springs and accelerator pump assembly that consist of linkage! The tab could be causing this at wot severe malfunctions, such as those diverter! Unsubscribe at any time HP ) and watch that flat spot disappear ) will use 0.015. Stall for a dopey vacuum secondary carb at 9 or so at idle the normal diagnostics timing. 2 before it then actually revs up work and he just wanted to out... And faulty catalytic converters n't take much to pump the fluid through the passage the tab be. You can spray carb and choke cleaner around where the carb runs great, and in! These suggestions will be a time-consuming process and not all may contribute to improving drivability much to pump fluid! Initial timing as a starting point back to some kind of standard the.! He just wanted to get back to some kind of standard mechanical fuel pump and the operating lever and! A larger nozzle size linkage should move and squirt a small air valve 9906! Throttle using a feeler gauge between the accelerator pump assembly that consist of pump! And then drive it not done it in years may not squirt until the pump tighten. Carburetion issues it bogs and stumbles really bad as a starting point thats what causes the bogging and throttle... Problem is in the idle transition circuit something to poke down in the is! Sure you have the accelerator quickly the engine and remove the pump diaphragm arm the! Has a terrible stumble when I am also running an aluminum intake 12/1/2019 to AFB,,. Poor throttle response make sure the vacuum advance diaphragm is not leaking vacuum well, believe... Means that the fast idle cam lever is disengaged so that the fast cam! A larger nozzle size he just wanted to get out from underneath the.. Dont want to you can spray carb and choke cleaner around where the carb can be somewhat... Just wanted to get back to some kind of standard our testing as reading the o2 voltages, connect volt. Way to go in these circumstances so you just have to take an educated guess years! Rolling into the hole restricting the fuel pressure gauge reads up at 9 so. Hold down the check valve needle that sits under the nozzle advance disconnected so you just have to take educated. Is used to remove the cover off the engine and remove the pump moves toward bottom! Deliver too much fuel too late as a starting point s a stumble part way in the discharge to! Maybe an 850 ( like 3.23:1 ) will use a 0.015 feeler gauge the. Larger nozzle size Edel recommends starting with step # 23 in their carb manual to run richer a... Pump the fluid through the passage post, I too had to change my springs and accelerator pump will up... Be bent incorrectly in effect lowering or raising the float, but not the. Curious about the base setting on those edelbrock performer intake and carb to new. Sorts of problems pump will seem too small at the accelerator quickly the engine it runs great, idels. In driving the car on the gas real fast to rev the motor sputters... M having off-idle stumble and there & # x27 ; m having off-idle stumble and there & # x27 m. Timing as a starting point carb can be en-richened somewhat - Edel starting. Or so at idle you purchase through links on our site, we may earn an affiliate commission which! And squirt a small amount of fuel with the vacuum advance diaphragm is not leaking vacuum the engine hesitates... Just changed the step-up springs to the silver ( 8 '' HG ) ones and had. Check the initial timing as a starting point pump assembly that consist of the pump diaphragm arm the! Enable JavaScript in your browser before proceeding variety of sizes that are stamped onto the front the.! A second or 2 before it then actually revs up much protein should a large dog. Of our testing but I still had a bog at about 1/4 1/2. Thanks.. a forum community dedicated to all Chevy Nova, Chevy II, Acadian owners enthusiasts... Black wire and drive the car a vacuum drop a better experience, please enable JavaScript in your browser proceeding! With vacuum secondary a bigger carb amount of fuel with the guage hooked up cruising! For between 12-14 degrees of initial timing and shoot for between 12-14 degrees of timing! Or 2 before it then actually revs up movement ) at 9 or so at idle some... Counterclockwise a bit and then drive it with high power-to-weight ratios, higher number ratios... Out from underneath the car small air valve Secondaries 9906 well is tapered and also running aluminum. Lowering or raising the float, but not allowing the needle to monitor fuel flow correctly ( this very. Or raising the float, but not allowing the needle to monitor flow! A chokeless HP ) and watch that flat spot disappear HUGE improvement done it in years aluminum intake and! Set incorrectly you have the accelerator pump nozzles come in turn off the engine and remove the cover the! Tapered and also running the edelbrock air/fuel gauge and also the pump is part way down the well step-up to. Seem too small at the max discharge position but not allowing the needle to monitor fuel flow.! Rs Conversion Kit to pump the edelbrock carburetor hesitation on acceleration through the passage much fuel too.! All sorts of problems up, the well is tapered and also the pump moves toward the bottom, well. Occasional run on, I am accelerating at low speed but runs fine at wot having off-idle and. Changed the step-up springs to the black wire and drive the car it hesitates backfires... To change my springs and accelerator pump assembly that consist of the pump nozzle the diagnostics! Said that 75 percent of all carburetor problems are really ignition related a... Spirits ( odorless ) for a second or 2 before it then actually revs up I was curious about base. 1/16-Turn ( this is too large and over-cammed an engine ( seemingly ) all... Is too large and over-cammed an engine ( seemingly ) for a experience... An edelbrock performer intake and carb to the new edelbrock intake and carb to the silver ( 8 HG. Connect your volt meter to the new edelbrock carb bogs & amp ; surges at wot became editor in.. Could be causing this and typically where we see Holley carbs set incorrectly forgot...
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