Editing Carburetor (section)

===Accelerator pump===
While the main metering circuit can adequately supply fuel to the engine in steady-state conditions, the inertia of  fuel (being higher than that of air) causes a temporary shortfall as the throttle is opened. Therefore, an accelerator pump is often used to briefly provide extra fuel as the throttle is opened.<ref>{{cite journal |author1=Packer, Ed |title=Know Your Carburetor- what it is, what it does |journal=Popular Mechanics |date=July 1953 |page=183 |url=https://books.google.com/books?id=ENwDAAAAMBAJ |access-date=19 November 2022 |publisher=Hearst Magazines |language=en}}</ref> When the driver presses the throttle pedal, a small [[piston pump|piston]] or [[diaphragm pump|diaphragm]] pump injects extra fuel directly into the carburetor throat.<ref>{{cite book|last1=Hillier |first1=V.A.W. |last2=Pittuck |first2=F.W. |year=1966 |title=Fundamentals of Motor Vehicle Technology |chapter=Section 3.6 |edition=Second |publisher=Hutchinson Educational |isbn=9780091107116}}</ref>

The accelerator pump can also be used to "prime" an engine with extra fuel prior to attempting a [[Cold start (automotive)|cold start]].{{citation needed|date=July 2023}}