1953-82 Corvette Superstore -- Classic Corvette Parts and Accessories, Including Carburetors, Starters, Alternators and More. everything is fine except for the bog just off. I am in the process of purchasing a slightly higher performance cam (Comp 12-206-2) to try. Holley Performance: Accelerator Pump Cam Adjustment About the Author This article was written by the It Still Runs team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information. Mine appears to be the normal size, but, Holley has a larger one available which is a 50cc size. The pump cam, a little plastic, color-coded part located on the throttle shaft with a single screw, will determine the total volume of the pump shot. If you don't find the products you are looking for, please call 714. Remove the air cleaner. Shop this selection of Accelerator Pump now. L0127: BOOK - Holley Carburetors, Manifolds & Fuel Injection revised 4th Edition, a detailed guide to Holley carburetors and manifolds, this book covered high-performance carburetors, selection and installation, the relationship between carburetors and manifolds, air and fuel requirements, and tuning for performance or economy, 223 pages with many photos. Inlet system air leak (faster idling). which accelerator pump cam for holley im trying to get this holley 4bbl tuned on my 302 with long tubes and edelbrock intake. they were called this because they have two accelerator pumps. This product is made of high-quality materials to serve you for years to come. More likely accelerator pump arm and cam not adjusted correctly, power valve too high, idle transition circuit not working correctly because the butterflys are open too far on the primaries, just for 3 possibilities if it's a Vacuum. They are available in a kit, part number 20-12 pictured below. No matter what squirter, pump cam, secondary spring, main jet change, within reason, you don;t want to add 10 numbers obviously, nothing helped. I watched Holley's video on how to adjust the pump arm, and I'm just verifying this is the correct procedure: Open throttle wide open (does this need to be done on the vehicle, or can I do it on the bench?) Depress pump arm completely; Turn adjustment screw until. 1) Inspect choke adjustment and for something binding. Would not go. HUME PERFORMANCE. For some engines, lengthening the pump shot by putting the rod in the top hole (the hole closest to the carb body) is enough to solve a stumble. ACCELERATOR PUMP CAMS There are nine different accelerator pump cams and each cam is a different. Adjust your accelerator pump to give max squirt and possibly get a bigger accelerator pump set-up(50cc) those are simple things to change that may help or fix problem. Here’s the deal, smaller shooters don’t empty the accelerator pump well as fast as the larger ones do. So i tossed it on. -----SCOOP. Holley offers an assortment of different pump cams, each with uniquely. FREE Shipping on orders over $25 shipped by Amazon. The 360 appears to be all stock. Automobile Parts and Service Toggle navigation Community Chevy Automotive Sales Inc. -main jets are #72-6. sku: ho121-25. 038 wire dia. The cruise mixture on a low boost, mild cam engine would be 1 to 1. correct accelerator pump cam for your specific application based on how aggressive the accelerator cam profile is. Contaminated or plugged low speed system. I will discuss carburetor size, describe how to set float levels, adjust idle and select the main jets. CAM KIT - accelerator pump, on throttle shaft arm, allows custom tailoring of accelerator pump response (8 different profiles & colors) accelerator pump adjusting. When the throttle is opened air moves much faster than fuel does through the carb and the squirt of fuel sustain the proper mixture until the rest of the fuel catches up. A little tunning up and down the road. Holley Accelerator Pump Cams. Adjust float tab for correct fuel level. which accelerator pump cam for holley im trying to get this holley 4bbl tuned on my 302 with long tubes and edelbrock intake. Holley has no other obligation express or implied. 040, as recommended by Holley. Custom tailor accelerator pump timing to your specific engine needs. FYI running 750 on a 440 with 484/284 cam. 5 power valve-green accelerator pump cam-. Should the cam arm make the pump open all the way? Or is there a reason why the cam arm stops before the pump is all the way open? Sorry for all the questions but this about the last of the holley I still don't get. I purchased a larger 40cc accelerator pump squirter and the screw with hole in the middle as holley recommended for any squirter above 39cc. pump system. CAM KIT - accelerator pump, on throttle shaft arm, allows custom tailoring of accelerator pump response (8 different. 015" clearance between screw and pump arm. Find Holley Accelerator Pump Cams 20-12 and get Free Shipping on Orders Over $99 at Summit Racing! Holley accelerator pump cams will allow you to "tailor" accelerator pump performance to your engine's actual requirements. Inside the accelerator pump housing, the pump diaphragm has a spring under it to push the. ACCELERATOR PUMP CAMS AND SHOOTERS Accelerator pump cams come in various sizes and are color coded and number coded by Holley. He then noticed that this same hack had tightened the accelerator pump adjustment until the spring was nearly coil bound, creating excessive clearance at idle, dramatically delaying actuating the. I don't know which, enough in the stream or long enough. Holley 20-80 White Accelerator Pump Cam. The Holley type accelerator pump system consists of three main components: the pump diaphragm, the pump cam, and the pump nozzle (a. To satisfy acceleration requirements in various climates the accelerating pump cam can be placed in one of two positions. com FREE DELIVERY possible on eligible purchases. It will meet your needs and deliver great quality at an affordable cost. Description Accelerator Pump Cam Assortment. First we adjusted the linkage to ensure that it is only lightly making contact at idle with the throttle closed. HOLLEY I-BARREL MODELS 1945, 1946, 1946-C a If accelerator pump adjustment is made on Chrysler Corp. Check accelerator pump Carn to ensure cam retaining screw is positioned in Specified hole in throttle lever. HOLLEY ACCELERATOR PUMP. Holley double. SOLD New Holley HP 550-606 EFI kit with TFI Harness & Knock Sensor ** NEW ** Fuel line from pump to Holley: Should I switch to the Borla ATAK or keep it classic Holley Blackheadt: Holley 350 on my 65 Mustang question: How do you adjust the accelerator pump on a holley truck avenger or 4160??. A power mixture of 6. This adjustment on AFB’s and Edelbroc k EPS series carbs does require a little bit of disassembly. Out of the box we had a stumble off idle that we were able to remedy by adjusting the accelerator pump. This adjustment gave you full pump stroke without bottoming the pump out at full throttle. Carb is good size you might have a bad secondary diaphragm. For oval track use, the pump lever should be adjusted so there is no play in the pump linkage when he throttle is closed. It comes in a gold iridited finish. 3) Check fuel delivery. Adjust if necessary. Holley 94 Rebuild Instructions. Also try adjusting the cam position so that it gives a big squirt at the RPM you're having a problem with. This product is made of high-quality materials to serve you for years to come. Adjust the accelerator pump linkage. Holley carburetors powered every Monster Energy NASCAR® Cup team and nearly every NHRA® Pro–Stock champion for four decades. 1 instead of no. transmission bracket kit 20-121 700R-4 kickdown throttle arm 20-12 Accelerator pump cam assortment 20-122 Pro series secondary linkage 26-137 Secondary adjusting lever kit 34-39 Billet adjustable fuel log Model 4150™ features. We couldn't see the latter interference readily. The pump lever spring travel must also be adjusted to allow 0. 50cc pump cams. This is a ProForm 750 Holley. Accelerator-Pump: The accelerator pump system adds a squirt of fuel directly into the main venturi. Holley says: "Accelerator pump shot relative to cam color from lightest to heaviest are as follows": Dominator pump cams. The first adjustment to check is the clearance between the pump operating lever and the pump diaphragm cover's arm, at wide open throttle. Im working on the accelerator pump adjustment on a Holley 750 DP that I am rebuilding. 015 extra movement of the pump arm so not to over stretch the pump diaphragm. My favorite tuning tool for carbs is a wide band O2 sensor. Holleys allow easy adjustment to circuits like the accelerator pump. There are two tuning parameters to the accelerator pump circuit: Pump Cam and Discharge Nozzle. Also includes service information for Holley 4160C carburetors used as service replacements for Motorcraft 4300 and 4350 carburetors. Holley 350 Carb Cam Adjustment - posted in Engine: Hi guys my standard 202 engine with a 350 Holley recently had a flat spot, putting your foot down the engine would choke out and possibly stall. 270-793-0900 www. your's has 4. Re: Holley accelerator cam and nozzle questions May 28th, 2013, 04:53 PM I put 2 little washers on the adjustment bolt of my 670 right under the hole from the arm, it seems to make the contact with the pump arm better,more exact since its kinda sloppy,I used the green pump cam in the #1 hole and a 31 squirter ,works good now. 5% CO while the high boost pressure hot cam cruise mixture is 3% CO. Of course, the approved adjustment may have changed due to daylight savings time, metric system, CE directives, or such. it idles fine and after the bog it runs ok. Holley 350 Carb Cam Adjustment - posted in Engine: Hi guys my standard 202 engine with a 350 Holley recently had a flat spot, putting your foot down the engine would choke out and possibly stall. Holley Carburetor Choke Adjustment Tips. The adjusting screw holds tension from a spring so if you loosen the locking screw without holding the adjusting screw it will unwind like a window blind and you'll have to start over again from zero tension (which is another story). Part# 120077. So it sounds like you need get more fuel during the transition. as its at an odd angle and kinda hidden by the accelerator pump cover. The complete pump mechanism consists of an inlet check valve, an outlet spray nozzle, a diaphragm, three springs that move the diaphragm, and the pump lock valve. How do you adjust the accelerator pump on a double pumper is a 4 barrel carb. transmission bracket kit 20-121 700R-4 kickdown throttle arm 20-12 Accelerator pump cam assortment 20-122 Pro series secondary linkage 26-137 Secondary adjusting lever kit 34-39 Billet adjustable fuel log Model 4150™ features. Adjust operating idle speed. With engine off, have an assistant hold throttle to WOT (wide open throttle). The brown is a 50cc pump cam; the chart is for the 30cc pump cams. Also try adjusting the cam position so that it gives a big squirt at the RPM you're having a problem with. Im working on the accelerator pump adjustment on a Holley 750 DP that I am rebuilding. The first adjustment to check is the clearance between the pump operating lever and the pump diaphragm cover's arm, at wide open throttle. The other cams can presumably be modified to work on a Dominator. After that I'd look at the check valves in the acc. When functioning properly, the full depression of the accelerator pedal will release the choke spring tension being held by the fast-idle cam and screw, while also providing a shot of fuel into the manifold by the accelerator pump. This is because the little passage cut in the side of the internal threads may not be big enough when you are way up in shot size, over. and best way to adjust 4 idle air screws on same carb. Noticed it came stock with a dark green accelerator pump cam. Re: Holley accelerator cam and nozzle questions May 28th, 2013, 04:53 PM I put 2 little washers on the adjustment bolt of my 670 right under the hole from the arm, it seems to make the contact with the pump arm better,more exact since its kinda sloppy,I used the green pump cam in the #1 hole and a 31 squirter ,works good now. The stock accelerator pump on a 4150-style carb has a capacity of 30 cc for ten strokes of the pump. 590 length walker products inc. The solution Holley came up with is a pump (or Accelerator Pump Discharge Nozzle) to shoot some fuel to help with the transition. I havnt checked accelerator pump measurements yet or the nylon fast idle cam behind the electric choke yet. The #1 & #2 refers to the holes in the throttle lever for the screw that attaches the cams, positions 1 and 2. Holley 1904 The accelerating pump stroke can be adjusted for seasonal or climatic changes by changing the position of the pump link in the throttle lever. quickfueltechnology. Find Holley Accelerator Pump Cams 20-12 and get Free Shipping on Orders Over $99 at Summit Racing! Holley accelerator pump cams will allow you to "tailor" accelerator pump performance to your engine's actual requirements. Try going down to a 24 shooter and see if that fixes the problem. commonly made by holley. And i dont think the electric choke is adjustable. 3) Check fuel delivery. Unfollow holley accelerator pump to stop getting updates on your eBay Feed. There's also a new secondary pump cam lever to provide for a positive throttle stop on the secondary side. With engine off, have an assistant hold throttle to WOT (wide open throttle). Next I tried the brains at Holley suggestion # 56 which was to go to a 50 cc pump so once again I'm sitting on my trailer tearing my carb apart pouring gas all over. The choke butterfly should be fully open, as the engine is warm. ) bog with giving it slight gas while driving stutters, shutters, wants to die out, occasionally gives a small pop out of carb, I'm guessing this has to do with size of accelerator pump nozzle? right now has. The accelerator pump comprises a pump cam, pump diaphragm and pump nozzle. Big cams need more initial spark at idle. Based on those posts it would seem that a lot of the Holley 2300 2bbl marine carbs seem to have the 50cc pump installed. I purchased a larger 40cc accelerator pump squirter and the screw with hole in the middle as holley recommended for any squirter above 39cc. If the fuel is coming entirely through the main boosters, the accelerator pump should not need to cover. That is: A suitable FPR is used to maintain steady fuel supply, even during dramatic changes in fuel demand. Should the cam arm make the pump open all the way? Or is there a reason why the cam arm stops before the pump is all the way open? Sorry for all the questions but this about the last of the holley I still don't get. He then noticed that this same hack had tightened the accelerator pump adjustment until the spring was nearly coil bound, creating excessive clearance at idle, dramatically delaying actuating the. everything is fine except for the bog just off. That will pump more gas earlier as I understand it. There are two tuning parameters to the accelerator pump circuit: Pump Cam and Discharge Nozzle. Holley Accelerator Pump Cover. 040, as recommended by Holley. CAM KIT - accelerator pump, on throttle shaft arm, allows custom tailoring of accelerator pump response (8 different. Adjust the accelerator pump linkage. The carb is a 750 cfm Holley 3310 4 bbl with vacuum secondaries. correct accelerator pump cam for your specific application based on how aggressive the accelerator cam profile is. If the fuel is coming entirely through the main boosters, the accelerator pump should not need to cover. The cams have different shaped ramps that the arm from the accelerator pump rides on. Sometimes referred top as the pump check, pump needle. When a mechanical cam-operated fuel pump came along, restrictions were lifted pump happy,” says Blane Burnett, Marketing and P. Holley 4000 Identification - The carburetor number is located on the back side of the carburetor on the face of the flange. If you have the stock pump cam (off white in color if I remember right) then the WOT procedure is correct and there shouldn't be any gap, or slack between the two arms at idle. The Holley's accelerator pump system differs from others in that instead of bending a linkage or changing the linkage mounting hole position, Holley uses plastic cams on the throttle arm. There are two. one on each float bowl on. First we adjusted the linkage to ensure that it is only lightly making contact at idle with the throttle closed. quickfueltechnology. In this quick video, Tom Kise of Holley goes over how to properly adjust the accelerator pump system on one of the company's carburetors. With engine off, have an assistant hold throttle to WOT (wide open throttle). On Dominator-style carbs, the pump capacity is 50 cc for ten strokes. How do you adjust a holley double pumper carb? Unanswered Questions. Re: Holley accelerator cam and nozzle questions May 28th, 2013, 04:53 PM I put 2 little washers on the adjustment bolt of my 670 right under the hole from the arm, it seems to make the contact with the pump arm better,more exact since its kinda sloppy,I used the green pump cam in the #1 hole and a 31 squirter ,works good now. pump system. Edelbrock is the most respected name in performance. Find Holley Accelerator Pump Cams 20-12 and get Free Shipping on Orders Over $99 at Summit Racing! Holley accelerator pump cams will allow you to "tailor" accelerator pump performance to your engine's actual requirements. I watched Holley's video on how to adjust the pump arm, and I'm just verifying this is the correct procedure: Open throttle wide open (does this need to be done on the vehicle, or can I do it on the bench?) Depress pump arm completely; Turn adjustment screw until. Get it as soon as Fri, Oct 25. The Q jet is a good carb, it has a centrally located fuel bowl that isn't as prone to flooding your engine (unless it has the old composite float) as the Holley or Carter (Edelbrock). The clearance should be 0. Here’s the deal, smaller shooters don’t empty the accelerator pump well as fast as the larger ones do. It comes in a gold iridited finish. Best Price On Holley Accelerator Pump Nozzless, Call 866-721-2315 to Speak with an ATK High Performance Engine Specialist today. With an umbrella style check valve there should be immediate flow regardless the rate the throttle is opened or the accelerator pump actuated. For any enquiries please contact us at. Out of the box we had a stumble off idle that we were able to remedy by adjusting the accelerator pump. 270-793-0900 www. No matter what you're driving, we have the right Holley Red Pump for your vehicle. 6 Liter Sohc 112. Unfollow holley accelerator pump to stop getting updates on your eBay Feed. (Left) The arrow points to the accelerator nozzle that discharges the fuel into the venturi. correct accelerator pump cam for your specific application based on how aggressive the accelerator cam profile is. The discharge nozzle, or "shooter," is available in different sizes, and determines the rate of. did it get better or worse? The engine is talking to you, it’s telling want it wants, if it got worse it’s still rich. Do I need to set the accelerator pump cam up to get a 'shot' with the faintest blip of the throttle - or do I need to spend more time with idle mix and t-slot adjustment?. Holley Pump Cam Kit Return Spring Adjusting Nut for Holley Needle & Seat Accelerator Pumps Accelerator Pump- Holley 5/8" x 2. Next I tried the brains at Holley suggestion # 56 which was to go to a 50 cc pump so once again I'm sitting on my trailer tearing my carb apart pouring gas all over. The accelerator pump cams are sized by color lightest to heaviest shot as follows: White, Blue, Red, Orange, Black, Green, Pink and Brown. so i was never able to get a proper count. Although adjusting the accelerator pump as described will create a lot of slop in the pump linkage at idle, (and may produce a stumble when driving in the pits) a car will leave harder. 020 on a holley. There is a check valve in the bowl that allows the pump to suck fuel from the bowl; if it's missing, the pump won't draw fuel and can't discharge any. 590 length walker products inc. Find many great new & used options and get the best deals for Carburetor Accelerator Pump Cam Holley 20-12 at the best online prices at eBay! Free shipping for many products!. You can find all the Holley technical videos, as well as some pretty fun videos of Holley events, dyno runs and interviews, at HolleyTV. There are two tuning parameters to the accelerator pump circuit: Pump Cam and Discharge Nozzle. 66-51 idle adjusting screw spring id. Holley offers a lot of tunability, and it has to be done in sequence to achieve the proper tuned carb. ) bog with giving it slight gas while driving stutters, shutters, wants to die out, occasionally gives a small pop out of carb, I'm guessing this has to do with size of accelerator pump nozzle? right now has. 2) Choke linkage binding. Find many great new & used options and get the best deals for Carburetor Accelerator Pump Cam Holley 20-12 at the best online prices at eBay! Free shipping for many products!. Under acceleration, or "off idle" carburetor demand, the accelerator pump injects fuel into the throttle bores for increased fuel atomization. Tuning advice for a Holley 2300 500CFM are different for each size ac pump and get an assortment of cams a holley carb tune book is in your future, explains all. A faulty accelerator pump will typically produce a noticeable effect on the engine performance when it fails or is having a problem. Once nozzle size has been selected, the accelerator-pump system can befurther tailored with the pump cam. You can adjust the position of the pump cam. The brown is a 50cc pump cam; the chart is for the 30cc pump cams. The single hole job is for a 50-cc pump, while the others are used on 30 cc pumps. I don't like carb work, don't know much about them. If it does not, take a look at the accelerator pump adjustment and make sure the cam is contacting the lever in the idle position. The pump lever spring travel must also be adjusted to allow. Pump cam kits can be purchased to change the rate in which the accelerator pump will ramp in the additional fuel. So any holley i get to rebuild or tune for someone always gets adjusted this way by me and i have had no issues---except you have to make sure the pump cam has a little lube on it because running it dry will occasionally have a tendency to not let the throttle close all the way and thus raising the idle a couple hundred rpm. Holley 0-80537 Model 4150 750 CFM Four Barrel Marine Carburetor with Mechanical Secondaries All Holley Marine Carburetors are designed to meet Coast Guard specifications. I have found that it is not always necessary to change the pump cam or hole position. Before changing the position, take a look at down the carburetor and make sure fuel squirts from the nozzle the instant you move the throttle. Make sure the float levels are set correctly (low float level will cause the problem you're having). If you have the stock pump cam (off white in color if I remember right) then the WOT procedure is correct and there shouldn't be any gap, or slack between the two arms at idle. I am in the process of purchasing a slightly higher performance cam (Comp 12-206-2) to try. FREE Shipping by Amazon. With some circle track and road race carbs it is desirable to nearly eliminate the accelerator pump function because the only need is for a little bit of squirt to start a cold engine and get past letting the clutch out. However, the pump plunger inside the carb is on a spring, and will only push so. 36-184 Accelerator pump tuning kit 36-182 Double Pumper tuning kit 20-95 GM A. I learn so much better by matching then reading about it. correct accelerator pump cam for your specific application based on how aggressive the accelerator cam profile is. Accelerator pump. TCI manual VB/Holley 750DP/Holley black pump. There must be a minimum of. The ideal accelerator pump shot is with the least amount of fuel that allows the engine to accelerate cleanly under all conditions. 015" free play between pump arm and WOT, idle vacuum at 14-15" hg in drive, power valve is 6. Part Number: 20-80; Application: Cam. How To Adjust The Accelerator Pump On Holley Carburetors - YouTube in this engine tech article HOT ROD compares the five best-selling Comp Cams camshafts for GM. 8cc too much fuel? I am having trouble adjusting the injection quantity of the accelerator pumps on my PMO carburetors (new installation), I initially measured each barrel and I get close to exactly. Moving to the metering block, JET will evaluate the engine size, breathing capacity, compression, and cam timing variables and recommend changes to both the emulsion circuits and. quickfueltechnology. 1,346 results for holley accelerator pump Save holley accelerator pump to get e-mail alerts and updates on your eBay Feed. But my business partner has a HT Monaro with a 350 holley and pretty much stock 202 Red bar extractors, exhaust, electronic dizzy and of course the Holley. Following the instructions outlined in the main text’s #11 tip, hold the bottom of the pump arm with a wrench and make the adjustments on the top nut with a 3/8-inch wrench. To adjust, turn the screw. Mercedes W203 C240 Engine From 6-speed 2002 V6-2. Try going down to a 24 shooter and see if that fixes the problem. CAM KIT - accelerator pump, on throttle shaft arm, allows custom tailoring of accelerator pump response (8 different. Assuming you have the accelerator pump lever adjustment correct (moves instantly as soon as you move the throttle lever), try turning your idle mixture screws out 1/8th turn on both sides. Re: Holley accelerator cam and nozzle questions May 28th, 2013, 04:53 PM I put 2 little washers on the adjustment bolt of my 670 right under the hole from the arm, it seems to make the contact with the pump arm better,more exact since its kinda sloppy,I used the green pump cam in the #1 hole and a 31 squirter ,works good now. As you may recall if I hit it and immediately get back out of it then it doesn't stumble at all. If you have the stock pump cam (off white in color if I remember right) then the WOT procedure is correct and there shouldn't be any gap, or slack between the two arms at idle. If an engine stumbles two or three times after the driver steps into the throttle this usually indicates too much fuel and can be corrected by. At idle there should be Zero clearance between the pump cam and the pump accelerator linkage arm. Check this out! Actual PROPER holley accel/pump cam chart A while ago, I noticed some very large errors in commercially available holley pump cam "specs" and charts. A marine carburetors fuel metering system is calibrated to compensate for unique engine loads found on boats. Following the instructions outlined in the main text’s #11 tip, hold the bottom of the pump arm with a wrench and make the adjustments on the top nut with a 3/8-inch wrench. HOLLEY ACCELERATOR PUMP DISCHARGE NOZZLE 0. In this quick video, Tom Kise of Holley goes over how to properly adjust the accelerator pump system on one of the company's carburetors. Holley Accelerator Pump Cover. 36-184 Accelerator pump tuning kit 36-182 Double Pumper tuning kit 20-95 GM A. I have refreshed my own experience with information from the following web sites. CAM KIT - accelerator pump, on throttle shaft arm, allows custom tailoring of accelerator pump response (8 different. The cams have different shaped ramps that the arm from the accelerator pump rides on. I learn so much better by matching then reading about it. Holley Aed Qft Ccs 4150 4160 Carburetor Accelerator Pump Cam Assortment 20-12 Holley Accelerator Pump Nozzle Check. The idle mixture is generally 1 to 1 1/2 turns out and both should be the same. The main parts of an accelerator pump consist of the pump diaphragm, pump cam and pump nozzle. Fuel Injection, Carburetion & Fuel System - Holley 1850 on 86 351 accelerator pump cam - got sick of the crazy things my old ford was doing, not starting and running like crap when it finally decided to start. There are just two Dominator pump cams that come with the larger throttle shaft profile, as shown below. A steeply-rising ramp shape will give a fast, heavy fuel shot right off idle. all 3 of the 4180s i have floating around were previously tampered with. The faster the throttle is opened while the idle/transistion circuit is supplying fuel, the more pump shot is needed. A little tunning up and down the road. 25/28/31, etc. Shop this selection of Accelerator Pump now. How do you adjust the accelerator pump on a double pumper is a 4 barrel carb. John, Have you adjusted the pump arm so that any movement of the throttle moves the pump arm? This is very important. First we adjusted the linkage to ensure that it is only lightly making contact at idle with the throttle closed. Holley Adjust-A-Jet Kit. What he doesn't mention is track tuning. This product is made of high-quality materials to serve you for years to come. PMO Carburetor Question? Accelerator Pump Adjustment - is. com with accelerator pump cam. Anybody know where to find a list of stock Holley accelerator pump cam usage? I have a 4777-1 650 double pumper, and while it runs great and the idle, jetting, etc are perfect, it has two pink cams on it (was set up by somebody else). When the throttle is opened air moves much faster than fuel does through the carb and the squirt of fuel sustain the proper mixture until the rest of the fuel catches up. Holley 23R258. No matter what squirter, pump cam, secondary spring, main jet change, within reason, you don;t want to add 10 numbers obviously, nothing helped. Should be made only if original setting has Changed. If the car blubbers initially then picks up it might need a pump cam adjustment. Accelerator pumps come with a cam adjustment slot for controlling the timing of the accelerator pump and sit right behind the "1, 2" adjustment screw. Also, if you order a pump cam kit, you will notice that the cams are double profiled. I don't like carb work, don't know much about them. Inlet system air leak (faster idling). The cams have different shaped ramps that the arm from the accelerator pump rides on. as its at an odd angle and kinda hidden by the accelerator pump cover. Refer to Figure 2 for what the accelerator pump discharge nozzles look like. Hold a straightedge across the top of the dust cover boss at the pump arm. Holley Avenger Carburetor Carburetors user reviews : 2. so i was never able to get a proper count. (2) Clean Carburetor with carburetor -cleaner, spraying down the main throats of the carburetor (with running engine at a fast idle, to prevent stalling). Shut off the engine. I am trying to adjust the shot on my 4010 750 Holley. correct accelerator pump cam for your specific application based on how aggressive the accelerator cam profile is. Another issue that can cause an off idle stumble on Holley carbs is the throttle plate /idle speed adjustment. 270-793-0900 www. We dyno tested the 800-cfm Quadrajet on a hydraulic roller cam-equipped 427 with remarkable. Edelbrock Air Horn Gasket Kit. Fast, secure e-book download. all 3 of the 4180s i have floating around were previously tampered with. The discharge nozzle, or "shooter," is available in. 015? of clearance to exist between the pump spring adjusting screw and the pump diaphragm arm at WOT. I adjusted the accel pump but that did no good. There's also a new secondary pump cam lever to provide for a positive throttle stop on the secondary side. Shop this selection of Accelerator Pump now. With pump cam (See Fig. 8cc too much fuel? I am having trouble adjusting the injection quantity of the accelerator pumps on my PMO carburetors (new installation), I initially measured each barrel and I get close to exactly. With engine off, have an assistant hold throttle to WOT (wide open throttle). My car has a serious bog (almost cuts out) when I get on the accelerator hard off idle and from below 2000 rpms, then it recovers and pulls hard the rest of the way. Buy Holley 20-12 Accelerator Pump Camshaft Assortment Kit: Cam & Lifter Kits - Amazon. 1 Adjusting Nut w/Gasket ; Holley Accelerator Pump Kit Click "More Info" For Kit Contents Holley 36-184. Pisses me off that Holley put these on the underside of the carb. This is done on automatic choke carburetors by first opening the choke butterfly by hand and inserting a wood block or wedge of some kind to hold open while the linkage is cycled (linkage operated through its full movement) to clear the choke cam. By the way, changing the pump cam requires readjustment of the free play. There are two. No matter what squirter, pump cam, secondary spring, main jet change, within reason, you don;t want to add 10 numbers obviously, nothing helped. On our 1971 1600dp engine, equipped with a 34PICT/3 carburetor and an alternator (1971 engines had generators), we found that the accelerator pump linkage was impinging on the alternator in two places -- the accelerator pump adjustment screw, and immediately forward of the accelerator pump itself. My favorite tuning tool for carbs is a wide band O2 sensor. An FPR that restricts the higher fuel flow alters the pressure control function of the FPR unit as well as increasing the load on the new fuel pump and modifying system fuel flow. 1) Inspect choke adjustment and for something binding. 015" clearance between screw and pump arm. 015" of clearance to exist between the pump spring adjusting screw and the pump diaphragm arm at WOT. I watched Holley's video on how to adjust the pump arm, and I'm just verifying this is the correct procedure: Open throttle wide open (does this need to be done on the vehicle, or can I do it on the bench?) Depress pump arm completely; Turn adjustment screw until. A little tunning up and down the road. How and Why to Adjust a Holley Carburetor Accelerator Pump Pump cams are replaceable, and as you can see, they can have two, three or even one hole. In addition, the cams have two different mount locations. Accelerator Pump arm adjustment: The accelerator pump arm must not be loose at idle. In this quick video, Tom Kise of Holley goes over how to properly adjust the accelerator pump system on one of the company's carburetors. your's has 4. Hold a straightedge across the top of the dust cover boss at the pump arm.