View source for Stall (engine)

{{Short description|Sudden cessation of engine operation caused by incorrect operation of a vehicles transmission}}{{For|the effects of a stall of the airfoil within the compressor of a jet engine|Compressor stall}}

A '''stall''' is the slowing or stopping of a process and in the case of an [[engine]] refers to a sudden stopping of the engine turning,<ref name=schultz>{{Citation |last = Schultz |first = Mort |date = March 1979 |title = How to stop stalling |magazine = Popular Mechanics |issn = 0032-4558 |oclc = 3643271 |url = https://books.google.com/books?id=cc8DAAAAMBAJ |access-date = 13 November 2014 |pages = 128–130 }}</ref> usually brought about accidentally.

It is commonly applied to the phenomenon whereby an engine abruptly ceases operating and stops turning. It might be due to not getting enough [[air]], [[energy]], [[fuel]], or [[electric spark]], fuel starvation, a mechanical failure, or in response to a sudden increase in engine load.<ref name=schultz/><ref>{{Citation |last = Hillier |first = Victor A. W. |date = 1990 |title = Fundamentals of Motor Vehicle Technology |edition = 4th |publisher = Nelson Thornes |publication-place = Cheltenham |isbn = 9780748705313 |oclc = 46761850 |url = https://books.google.com/books?id=2_QQtv4pFoIC |access-date = 13 November 2014 |page = 223 }}</ref> This increase in engine load is common in vehicles with a [[manual transmission]] when the [[clutch]] is released too suddenly.<ref name=wardlaw>{{Citation |last = Wardlaw |first = Christian |date = 11 August 2014 |title = Get the most out of your car: How to drive a manual transmission |work = Daily News |location = New York |url = http://www.nydailynews.com/autos/buyers-guide/car-drive-manual-transmission-article-1.1899332 |access-date = 14 November 2014 |archive-url = https://web.archive.org/web/20140813044152/http://www.nydailynews.com/autos/buyers-guide/car-drive-manual-transmission-article-1.1899332 |archive-date = 13 August 2014 }}</ref>

The ways in which a car can stall are usually down to the driver, especially with a manual transmission. For instance, if a driver takes their foot off the clutch too quickly while stationary then the car will stall; taking the foot off the clutch slowly will stop this from happening. Stalling also happens when the driver forgets to depress the clutch and/or change to neutral while coming to a stop.<ref name=wardlaw/> Stalling can be dangerous, especially in heavy traffic.<ref name=schultz/>

A car fitted with an [[automatic transmission]] could also have its engine stalled when the vehicle is travelling in the opposite direction to the selected gear.<ref>{{Citation |last = Roth |first = Dan |date = 20 August 2009 |title = What Would Happen If You Put Your Car In Reverse While Driving? |work = AOL |url = http://autos.aol.com/article/reverse-transmission/ |access-date = 14 November 2014 |archive-url = https://web.archive.org/web/20090826165151/http://autos.aol.com/article/reverse-transmission |archive-date = 26 August 2009 }}</ref> For example, if the selector is in the 'D' position and the car is moving backwards, (on a steep enough hill to overcome the torque from the [[torque converter]]) the engine will stall, due to the fact that the engine is forced to turn in the opposite direction to what it is actually doing. This is because, hypothetically, if the car is rolling backward fast enough, the force from the rotating wheels will be transmitted backward through the transmission and act as a sudden load on the engine.

[[Fuel_injection#Multi-point injection|Digital electronics fuel injection]] and [[Engine control unit|ECU]] [[ignition system]]s have greatly reduced stalling in modern engines.<ref>{{Citation |last = Hatch |first = Steve V. |date = 2012 |title = Computerized engine controls |edition = 9th |publisher = Delmar, Cengage Learning |publication-place = Clifton Park |isbn = 9781111134907 |oclc = 676729348 |url = https://books.google.com/books?id=zst2aOSNnCkC |access-date = 13 November 2014 |page = 529 }}</ref>

==See also==
* [[Stall torque]]

==References==
{{Reflist}}


[[Category:Mechanics]]
[[Category:Machines]]
[[Category:Driving techniques]]
[[Category:Automobile engines]]
[[Category:Distress signals]]

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