Hesitation at initial acceleration
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Joined: Mar 2016
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Hesitation at initial acceleration
I have a 78 L82 auto, low miles very original thus it has Q-jet. I have done a carb rebuild. So overall it runs fine but I have a hesitation when: from stop push on pedal and for about a 1/2 sec it accelerates just fine, then for about a 1/2 second there is a hesitation, then it is fine again. I have already replaced the accel pump so expect that is not the issue. Thoughts?
Melting Slicks
Joined: Apr 2021
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From: Minnesota
Too much vacuum advance can cause a bog off idle. And if it needs more vacuum to be all in than what your engine produces it will cause a “wandering” idle, as well as other issues.
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When you rebuilt the carburetor did you use Cliffs book as a guide?
Did you check the accelerator pump check ball at the bottom of the pump casting?
Did you polish the pump chamber?
Do you have the pump arm on the inner hole?
Did you check the accelerator pump check ball at the bottom of the pump casting?
Did you polish the pump chamber?
Do you have the pump arm on the inner hole?
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You may want to read this
https://www.themotorbookstore.com/how-to-rebuild-and-modify-rochester-quadrajet-carburetors.html?gad_source=1&gad_campai gnid=1806641261&gclid=CjwKCAiAqKbMBhBmEi wAZ3UboLxWjL8uRj_Eo7FlUgceLbNTJuRkL4t_SG iWV0TH2b6XNzHzHAi8jBoCytYQAvD_BwE
https://www.themotorbookstore.com/how-to-rebuild-and-modify-rochester-quadrajet-carburetors.html?gad_source=1&gad_campai gnid=1806641261&gclid=CjwKCAiAqKbMBhBmEi wAZ3UboLxWjL8uRj_Eo7FlUgceLbNTJuRkL4t_SG iWV0TH2b6XNzHzHAi8jBoCytYQAvD_BwE
Last edited by MelWff; Feb 9, 2026 at 10:42 PM.
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Sorry, somehow the wrong link was attached. I meant to attach a link to Cliff's book.
https://www.themotorbookstore.com/how-to-rebuild-and-modify-rochester-quadrajet-carburetors.html?gad_source=1&gad_campai gnid=1806641261&gclid=CjwKCAiAqKbMBhBmEi wAZ3UboLxWjL8uRj_Eo7FlUgceLbNTJuRkL4t_SG iWV0TH2b6XNzHzHAi8jBoCytYQAvD_BwE
https://www.themotorbookstore.com/how-to-rebuild-and-modify-rochester-quadrajet-carburetors.html?gad_source=1&gad_campai gnid=1806641261&gclid=CjwKCAiAqKbMBhBmEi wAZ3UboLxWjL8uRj_Eo7FlUgceLbNTJuRkL4t_SG iWV0TH2b6XNzHzHAi8jBoCytYQAvD_BwE
