Hi I'm starting out in this industry so I'm too young to have ever met a carbureted vehicle. I have a question about the "dashpot" on carbs, sometimes called an "antistall" dashpot.

From what I gather it prevens the throttle from snapping shut when released, letting it taper closed gradually. I don't really understand why that's necessary though.

In books it says that its necessary with automatic transmissions and seems to be related to the vehicle speed.

If you are doing 60-70 and you go to coast down to 50 and so you let off the throttle completely... shouldn't the vehicle have enough speed to just coast without putting a load on the engine?

If you're driving at low speeds it seems like that might be necessary though, low speeds / low power there will be more engine loading. When the vehicle doesn't want to coast really.

I'm asking because the modern engine management systems cars are using control the idle air bypassing the throttle to do the job the dashpot used to do.

Andrew Libert
Technician
General Motors
Ann Arbor, Michigan, USA