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Ok guys, here is a question. My car has been stumbling when I just start to accelerate when driving around town. The only way it won't do it is when I give it a lot more gas, but around town I try not to always ride the pedal. So, Last night I changed my accelerator pump cam to the black cam profile. I am running a size 37 nozzle in the primaries and size 35 in the secondaries. Also it did the same stumble when I was going about 45mph and tried to give it a pump of gas (press the pedal down). Anyone have any ideas??? To large or too small pump nozzles?? Wrong pump cam??
 

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Wow!, thats a big question with so few details. What car?, engine size?, modifications?, carb size?, jetting? etc. (Fill out your Bio :eek:)

I'll take a stab at it:
First, get a piece of paper and write down everything about the carb. Jetting, squirter sizes, cam color & position, Accelerator pump size, etc.
Then, write down the problems.
After you've done that change ONE thing, drive it, and write down everything again. Keep this log going, it's VERY helpful.

First thing I would do is put a 31 squirter in the primaries and give it try
 

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More information on the vehicle and drivetrain is required.

You have a double pumper with nozzles large enough to feed a racing 460. I'm hoping that's what you have. Otherwise, too much gas is getting in. If you don't have Reo pumps on either primary, secondary or both, you're likely running short on pump duration.

Get back to us...
 

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I wouldn't assume it was the carb to begin with. Timing and vacuum advance can do the same thing to your performance. Points & condensor (if you have them), rotor, distributor cap, wiring, plugs, coil, all have to be doing their job. When you have any kind of performance problem, make sure the ignition system is thoroughly tuned up, and timing is correct, before attacking the carb. Sorry if you have already done this, but it wasn't mentioned. I see a lot of carbs mutilated prematurely on forum members cars.
 
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