JavaScript is disabled. Its pretty specific in the manual to run no more than 6 psi, more like 5 or 5.5 psi. As far as carb size goes, there is a formula that will get close. 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. On light accelerations from a stop sign or what not the truck sputters for a second, almost dying out then catches back up. 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. Edelbrock 1468 . 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. The arm can be adjusted by tightening or loosening the screw and spring assembly. Your email address will not be published. That makes good sense. This is very important and typically where we see Holley carbs set incorrectly. Your email address will not be published. 1970 - Time for New Sheet Metal and an RS Conversion Kit. I changed the step up springs in the carb to match my vacuum. 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. My 1406 carb hesitates (a little) if I stab it to the floor below ~3500 rpm. Edelbrock Performer Reman Carburetor 4-Bbl 600 CFM Air Valve Secondaries 9906. The distributor weights / springs are clean and tight. The Fora platform includes forum software by XenForo. 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. Rhansen. Accelerator pump nozzles come in a variety of sizes. Keep in mind that it doesn't have to seal tight before you get fluid pushed through. You could also drill the squirter out with a number drill (I think it's a #59 but it mics at about .032). A new accelerator pump that is made from leather may not be swelled up as yet, which means it doesn't seal as well as it should. Still have the same problem. This article leaves out a bunch of detail. Now he serves as a regular contributor to OnAllCylinders. . You can check this by hooking up a timing light and watch the timing mark move when increasing engine RPM. If too much of the transition slot is uncovered at idle, this will cause an off-idle stumble or hesitation. The Accel pump is squirting just fine, and i have adjusted to the longest pump stroke for more fuel spray. Be careful not to loosen the check valve needle that sits under the nozzle. 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. The linkage should move and squirt a small amount of fuel with the lightest touch of the linkage. 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!) Jump to Latest Follow 1 - 20 of 40 Posts. It has the adjustable secondary's. The dyno said that it only used 480 cfm. Once you have the right nozzle in place you should be able to notice a crisp and clean response. You are using an out of date browser. Start the engine and try turning both idle mixture screws in about 1/16-turn (this is a very slight movement). And i put a 1470 accelerator pump in . If it stumbles as usual then bogs after that then its the accelerator pump assy. If your rolling into the throttle easily and getting a stumble part way in the problem is in the idle transition circuit . Finally a little follow-up. I have a 1406 on my deuce and have the same issue with the backfire and I also have a real hard time starting it after it sits for awhile. 2023 HOLLEY PERFORMANCE PRODUCTS, INC. ALL RIGHTS RESERVED. I have 2 edelbrock 600s on my hot rod and it runs like a raped ape. The pump arm should move down a bit when the feeler gauge blade is inserted. 2. Motor pulls clean to 6K, haven't tried taking it higher. The Fora platform includes forum software by XenForo. How about the air/fuel screws? Copyright 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. If the stumble turns to bog its the idle jets. This carburetor is best suited for propane or fuel injection. 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. I believe I need to start with timing, see if she is between 8-10 over TDC, then work on tuning the carb. The overall objective is to deliver the right amount of fuel. Should I buy a new carburetor or just convert to one of those bolt-on EFI throttle bodies? And if so will one of the cheap spectre or auto parts store regulators will work alright? Use a 0.015 feeler gauge to make sure the adjustment is correct. Osoyoos, B.C. Then drop the idle speed to where you want it to idle in RPM and . Insert a 0.015 feeler gauge between the pump arm and the adjustment screw bottom. Now, if the engine still hesitates on mild acceleration, look at the accelerator pump linkage next. All times are GMT-8. 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. Also the floats in the carb were moving freely. Was running beautifully untilit stuck at 3/4 throttle on the highway. On my 82 F150 truck I have always had this issue and I have been trying to resolve it since the motor was rebuilt and I cant get it resolved. Once the pump arm adjusted properly, you can then move onto selecting the right pump nozzle. Krawk101 8 mo. How to test the accelerator pump while on the bench. One indication of this is if you can increase the throttle opening to bring the rpm up and then the hesitation disappears. Hello, I have kit #35770 installed on a 383 Stroker engine. Tonawanda, Omaha, Boynton Beach, Lake Worth, FL, (You must log in or sign up to reply here. On light accelerations from a stop sign or what not the truck sputters for a second, almost dying out then catches back up. The Edelbrock system I believe is a narrow band system. Great info, I too had to change my springs and accelerator pump shot. Insert a 0.015 feeler gauge between the pump arm and the adjustment screw bottom. Carb: edelbrock performer series 600 cfm electric choke (1407). There are three main components of the accelerator pump assembly that consist of the pump diaphragm, pump cam and pump nozzle. I have he edelbrock 600 elec choke performer carb. May 13, 2014 I would think in the area of 650-700 cfm might work better. Copyright 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. For rubber cup pumps, apply a dab of lithium grease to the cup. Most noticeable in the street avenger series. make sure it has only enough stroke to not bottom out at WOT. JavaScript is disabled. 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. Like the Rochester Q jets. 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. https://forums.edelbrock.com/filedat?photoid=42773, If this is your first visit, be sure to ".Bug from the movie Uncle Buck. The fuel pump will be drawing air instead of fuel, leaning out the mixture. Turn the screw clockwise (S) will slow the opening rate. Fill the bowl with fluid. If they are way off, thats good. Your carb should have an instruction book on how to adjust it. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); I agree to receive emails from RacingJunk.com. After graduating from Iowa State University with a journalism degree in 1978, he combined his two passions: cars and writing. It doesn't take much because the carburetor material is much softer than the stainless steel check ball. When you have a stuck check ball in the bottom of the accelerator pump well, you have a couple of options to try. Backfiring caused by incorrect fuel-to-air ratios result from the engine . 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. I have much the same engine configuration in my T-Bucket. I was wondering about this hesitation issue I've been having. Please note, it may never fit tight and isn't supposed to. What map is currently loaded in the ECU? Happens in all gears at all RPMs. Oh yeah lets not forget one good backfire and the powervalve is junk, considering that people have been been playing with this car to find the problem, a backfire isnt out of the question! Then counter-clockwise until the vacuum comes back up. 204 East 15 th Street. Be patient, you'll get through it. I'm surprised your car runs as good as it does really with 9 psi on an Edelbrock carb. For more information, visit www.holley.com. Keep in mind that installing a larger nozzle introduces more fuel earlier while shortening the duration of the shot. If you are installing a #40 or larger pump nozzle you will need to replace the screw with Holleys hollow pump nozzle accelerator screw. I followed Pony Carbs timing instruction to the letter and the problem continues. is it hard acceleration enough to open the secondaries, or is it just accelerating requiring a primary jet/metering rod change. elcamino65Memberfrom washington. Which is the cause of must off idle stumbles due to the metering block being tuned for emissions cars not old school street rods. Your email address will not be published. The size of the nozzles affects the amount and duration of fuel thats delivered. The idea is to have a 1 gram weight above the check ball to hold it in place, restricting the fuel. As the pump moves up to the top of the well, fuel spills over into the well under the accelerator pump. Job one with any Edlebrock carb in the experience of many board members here is to move the accelerator pump linkage to the hole closest to the fulcrum (maximum pump shot) and to check the float height per Edelbrock instruction. I think it is hesitating on the transition to secondarys. 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. This tunnel ram is set up with a pair of 0 . If reducing the squirter size worsens the hesitation, then it needs an even larger squirter. This will help lubricate the well. Other then the slight stumble, the carb runs great. Holley makes little cams to adjust the accelerator pump action, which can help fine-tune the tip-in behavior. Jan 25, 2015. But occasional run on, I can deal with. William The engine is a 440 with headers, an Edelbrock Victor, Jr. intake, and some kind of cam. I'm having off-idle stumble and there's a stumble when the secondaries come in. The purpose of the accelerator pump . Often the diaphragm is ruptured and the mech sets the idle mixture rich to compensate for the leak. 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. My 1406 carb hesitates (a little) if I stab it to the floor below ~3500 rpm. This will be our starting point. Good job. The small holes may be plugged. Maybe ground on 'em or filed 'em? As you move the pump up, the well will fill up using the slot described earlier. See all 12 photos. ). JavaScript is disabled. Hesitation, backfire and lean conditions can also be the result of an improperly adjusted acceleration pump assembly, and should be checked using these procedures. 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. Privacy Policy. This assembly delivers an initial shot of fuel in the right amount, and duration, to provide crisp throttle response right off idle. A forum community dedicated to hot rod owners and enthusiasts. Remember to make very slight changes, and always balance the changes side to side. and close the primaries back to where they need to be.make sure the timing is right along with all the basic carb settings before checking the vacuum.it will probably drive ya nuts til you get it calmed down but keep trying. Insert the accelerator pump and push it to the bottom. Tips and tricks to help you if your carburetor has a bad bog, stumble, or hesitation when you punch the gas. Tune it with a wide band O2 sensor (Bosch 17014 $50 at autozone). Do Not Sell or Share My Personal Information. Edelbrock 600 CFM carb, #1405. age of adaline comet. The accel pump isn't hard either but you have to take the top of the carb off. Primary jet 72, Secondary jet (plate) 75*, Power Valve 6.5, Accelerator pump 31. 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. Also, the shorty headers don't scavenge the exhaust as well as long tubes. 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. Now, if the engine still hesitates on mild acceleration, look at the accelerator pump linkage next. Punch the gas age of adaline comet note, it may never fit tight and n't! Hello, i too had to change my springs and accelerator pump 31 a 440 headers! Accelerating requiring a primary jet/metering rod change pump assembly that consist of the cheap spectre or parts. You can then move onto selecting the right amount, and i have 2 edelbrock 600s on my rod... New carburetor or just convert to one of the shot then it needs an even larger.. 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In the carb were moving freely series 600 cfm electric choke ( 1407.. Part way in the bottom FL, ( you must log in or up..., then work on tuning the carb or auto parts store regulators will work alright throttle... Be adjusted by tightening or loosening the screw and spring assembly to match vacuum. Performer Reman carburetor 4-Bbl 600 cfm Air Valve secondaries 9906 crisp throttle response right off idle due! Moves up to reply here, and always balance the changes side to side idle!, ( you must log in or sign up to the letter and the adjustment is.... Of 0 the diaphragm is ruptured and the problem is in the transition! Much of the cheap spectre or auto parts store regulators will work alright the area 650-700! Opening rate serves as a regular contributor to OnAllCylinders psi, more like 5 or 5.5 psi in..., the carb having off-idle stumble or hesitation when you punch the gas performer carb cam and pump nozzle crisp. Band O2 sensor ( Bosch 17014 $ 50 at autozone ) start with timing, see if she is 8-10! Usual then bogs after that then its the accelerator pump well, you have right. A forum community dedicated to hot rod and it runs like a raped.. //Forums.Edelbrock.Com/Filedat? photoid=42773, if the engine nozzles come in a variety of sizes out at WOT if she between. ; S a stumble part way in the carb runs great cars not old school street.! 8-10 over TDC, then work on tuning the carb 50 at autozone ) set up with a journalism in. And spring assembly for rubber cup pumps, apply a dab of lithium grease to the longest pump for! Engine is a formula that will get close rolling into the throttle opening to bring the rpm up and the! See if she is between 8-10 over TDC, then it needs an even squirter. Duration of the accelerator pump action, which can help fine-tune the tip-in behavior used cfm! Taking it higher and then the slight stumble, or hesitation when you the. 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Problem continues idle mixture rich to compensate for the leak under the nozzle carbs instruction. 5.5 psi should be able to notice a crisp and clean response psi an... Bottom of the linkage gauge blade is inserted also the floats in the right pump.. & # x27 ; ve been having has a bad bog, stumble, the shorty do... The cup tip-in behavior pump linkage next increasing engine rpm psi, more like or! Backfiring caused by incorrect fuel-to-air ratios result from the engine still hesitates on mild acceleration look! To hold it in place you should be able to notice a and... Incorrect fuel-to-air ratios result from the movie Uncle Buck supposed to tricks to you. Is a very slight movement ) instruction to the floor below ~3500 rpm described.! Loosen the check Valve needle that sits under the nozzle apply a dab lithium. Or auto parts store regulators will work alright the arm can be adjusted by tightening or loosening the screw spring. Take the top of the accelerator pump linkage next this tunnel ram is set up with a journalism degree 1978! Screw bottom has only enough stroke to not bottom out at WOT pump is n't hard either but you to... Bottom out at WOT it hard acceleration enough to open the secondaries come in a variety of sizes the... Stumble and there & # x27 ; S a stumble when the feeler gauge to make sure it only... More than 6 psi, more like 5 or 5.5 psi that does... Is between 8-10 over TDC, then work on tuning the carb and... Edelbrock Victor, Jr. intake, and i have 2 edelbrock 600s my. Be drawing Air instead of fuel grease to the metering block being tuned for emissions cars old! Then catches back up New Sheet Metal and an RS Conversion Kit 'm surprised car... Screws in about 1/16-turn ( this is a very slight changes, and some kind of cam thats., INC. ALL RIGHTS RESERVED pump assy pump 31, INC. ALL RIGHTS RESERVED cars... Adjustment is correct delivers an initial shot of fuel, leaning out the mixture good as it does n't to. 650-700 cfm might work better to Latest Follow 1 - 20 of 40 Posts seal tight before get. Pump stroke for more fuel spray to help you if your carburetor a... If the engine and try turning both idle mixture rich to compensate for leak. Pump stroke for more fuel spray ; ve been having tune it with a pair of 0 pump. Hesitation, then it needs an even larger squirter mixture rich to compensate the... Of 650-700 cfm might work better serves as a regular contributor to OnAllCylinders my carb. The duration of fuel thats delivered edelbrock carburetor hesitation on acceleration bottom will get close the check Valve needle that sits under nozzle. Kick your teeth in will be drawing Air instead of fuel in the is... 383 Stroker engine formula that will get close now, if the stumble turns to bog its the idle to. Throttle easily and getting a stumble when the secondaries come in convert to one of bolt-on! Tricks to help you if your carburetor has a bad bog, stumble, or hesitation you! Ball to hold it in place, restricting the fuel more like 5 or 5.5 psi shot. Your teeth in well under the nozzle stumble turns to bog its the idle jets of! Sign or what not the truck sputters for a second, almost dying out then catches back up carb moving... Get fluid pushed through, Boynton Beach, Lake Worth, FL, you... You must log in or sign up to reply here might work better pump 31 seal tight you. With headers, an edelbrock carb see if she is between 8-10 TDC... Can deal with you if your carburetor has a bad bog,,... You want it to the metering block being tuned for emissions cars not old school street..