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Accelerator Pump Nozzle

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Old Nov 4, 2006 | 06:16 PM
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MetalliCamaro68's Avatar
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Accelerator Pump Nozzle

I read in a post that Pablo wrote that you can drill the accelerator pump nozzle out with a pin drill to make it bigger. Is this advisable? What is the biggest Edelbrock pump nozzle? I have the stock one on at 750cfm.
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Old Dec 4, 2006 | 08:24 PM
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From: maine
Car: 1986 iroc z
Engine: vortec 383
Transmission: th350
Axle/Gears: 3.73 moser 12 bolt true trac
why bother just get the right size you need.
It sounds like you really dont understand what the accelerator pump nozzle's job is. If you car is acclerating good with no hesitation than you will see no gains by messing with the pump shot duration.
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Old Dec 5, 2006 | 11:32 AM
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From: Bay Area, CA
Car: 1984 Camaro Z28
Engine: Roller 350
Transmission: T-5
Axle/Gears: built ten bolt 3.73's
All that nozzle is used for is extra fuel during the transition from the idle system to the main metering system. Like rjt76 said, if your car does not have acceleration problems between part and wide open throttle, ie no bog, then there should be absolutly no reason to drill these biggers. Rods and jet changes are a better choice for tuning then drilling these.
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Old Dec 5, 2006 | 12:16 PM
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Originally Posted by rjt76
why bother just get the right size you need.
It sounds like you really dont understand what the accelerator pump nozzle's job is. If you car is acclerating good with no hesitation than you will see no gains by messing with the pump shot duration.
Umm, what do you mean I dont understand what its job is??? I said nothing about its use.

All I asked was if it was aviseable to make the inside diameter larger by drilling it out. The reason I need a bigger nozzle is because it does have acceleration problems off idle.
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Old Dec 5, 2006 | 06:27 PM
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From: maine
Car: 1986 iroc z
Engine: vortec 383
Transmission: th350
Axle/Gears: 3.73 moser 12 bolt true trac
The accelerator pump and nozzles job is to shoot fuel (amount and time duration) needs to be correct or their will be a bog or hesitation when accelerated hard. The vehicle can actually stall out if it is to far off calibration. Or shoot flames out the carb.

Fuel will be suspended when vacuum falls to near zero when the throttle blades are opened rapidly. The pump shot is their to provide fuel when this occurs. The right amount of fuel is when their is no stalling or bogging, hesitating ect...Since you made no reference to the vehicle running poorly I assumed you wanted to mess with the nozzle for performance gains. This would not gain you anything by doing so.
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Old Dec 5, 2006 | 07:35 PM
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Apeiron's Avatar
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From: Mercedes Norte, Heredia, Costa Rica
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
What kind of off-idle problem do you have?
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Old Dec 5, 2006 | 10:42 PM
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I dont have to stomp on the gas for it to bog, I can just go about taking off normally and it just doesnt really want to go unless I kinda pump it a bit. Then it takes off fast.
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