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Discussion Starter #1
Hello,
Can someone explain this paragraph to me....
QUESTION My vehicle has a stumble from a dead stop. What can I do to cure this?
ANSWER The most common cause of a stumble is not having an adequate accelerator pump shot. The first thing to do is to look at the discharge nozzle and make sure you are getting a good strong pump shot. If not then you need to inspect the pump diaphram for a hole or tear. You will also need to make sure that the pump passage is clear from any trash or debris. First you will need to check the adjustment on the pump. To do this you will open the throttle all the way (WOT). Push the pump arm lever down and then adjust the pump override spring to obtain .015" clearance between the pump arm and lever. If you are having a stumble and no black smoke out the tailpipe then you will need to increase the shooter size. If it stumbles and you are getting black smoke from the tailpipe then it will be nessasary to decrease the shooter size.

so my question is the last 2 sentences....*increase the shooter size*..*decrease the shooter size* are they refering to the accelerator pump discharge nozzle(squirter)?I have stumble at initial accelreration...and i have a good squirt.My Nozzle is an .031...should I go up to a .032?Also...in the paragraph(this makes no sense to me??)The say to check the adjustment of the pump...moce throttle to WOT...There should be a .015 between the pump arm and lever?How can this be...wide open throttle is pushing down on the lever??No gap..0....does this make sense what i'm saying?Thanks for the help..bm
 

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Richen the idle mixture screws first, and see if it improves--takes 2 seconds and won't cost anything.
Then give it more initial timing.
 

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Discussion Starter #3
Richen the idle mixture screws first, and see if it improves--takes 2 seconds and won't cost anything.
Then give it more initial timing.
Did both..didn't work.I'll keep fiddling...i have to get a holley book.I was hoping someone could decipher their quote.thanks bm
 

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FIRST!!!!!!!

Are you stomping the gas from a dead idle??
And what cam do we have?? Your combination might not start working at idle.
Also a cold heat range plug can cause this.

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Pump adjustment! (The lever arm)
I always get my Idle set first.
Then set the pump to "0" tolerance.
I do this after idle is set because the throttle arm does move during this adjustment.
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Also ignition timing plays a bigger part of of idle acceleration.
Move it around, there is no magical number!

Al
 

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Discussion Starter #5
FIRST!!!!!!!

Are you stomping the gas from a dead idle??
And what cam do we have?? Your combination might not start working at idle.
Also a cold heat range plug can cause this.

---------

Pump adjustment! (The lever arm)
I always get my Idle set first.
Then set the pump to "0" tolerance.
I do this after idle is set because the throttle arm does move during this adjustment.
-----------------------
Also ignition timing plays a bigger part of of idle acceleration.
Move it around, there is no magical number!

Al
yes..my idle is adjusted.750 rpms in park.idle mixture screws are ste at 1 full turn out...this is my highest vacuum reading...16 in mercury....I set the arm at 0..its alot better now....almost there.The one thing I will say about this holley...it screams at wot...faster then I have ever been in my car:eek::eek::D:D
 

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yes..my idle is adjusted.750 rpms in park.idle mixture screws are ste at 1 full turn out...this is my highest vacuum reading...16 in mercury....I set the arm at 0..its alot better now....almost there.The one thing I will say about this holley...it screams at wot...faster then I have ever been in my car:eek::eek::D:D

If the adjustment made this better.
I would go to a larger squirter.
I would try a .32, we want to keep this to a min. This does effect fuel mileage for city driving drastically.

Holley 121-132 is the standard .32 nozzle.


Al
 

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yes to all of the above and if you don't have a squirter or can't locate one try changing the accelerator pump cam to a bigger one or move it from the first hole or second hole. Be sure to readjust the pump spring after changing the cam.
 
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