electronic throttle
in [Technical]
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From: David Skelton on 8 Mar 2010 05:28 <clare(a)snyder.on.ca> wrote in message news:6ha8p5lum13dounlkv19cscf48rhn9rh5c(a)4ax.com... > On Sun, 7 Mar 2010 11:44:57 -0000, "David Skelton" > <skellyd8758(a)skynospam.com> wrote: > >>We have had three cars (one made in 1997, the second in 2002 and the >>third >>in 2004) that sometimes used to open the throttle on the 'over run', >>possibly to reduce emissions. >> >>It was unnerving approaching junctions. >> >>All three had mechanical throttle cables, but also motors built into the >>throttle body to drive the throttle plate open. >> >>Two were Fords, the other was a Daewoo with a Suzuki engine. >> >>Best wishes >> >>David >> >> >> >>--- news://freenews.netfront.net/ - complaints: news(a)netfront.net --- > Virtually ALL port injected engines have an electrically operated > "idle speed control" or "air bypass" valve that bypasses air past the > throttle valve for several purposes. It is uded to raise (or maintain) > idle speed when AC is operated, headlights are turned on, or power > steering is used at idle, and it is used to prevent abrupt throttle > closure on decel for emission reasons. > Some older vehicles used an "idle up" solenoid for the same purpose, > while others had an "anti-diesel" solenoid to close the throttle > completely when the ignition was turned off. Other older vehicles used > a "dash pot" or vacuum idle control to do some of the same. > > Vehicles with Drive By Wire, in large part, eliminate the ISC system - > which, by the way, is one of the more problem prone subsystems on most > fuel injected vehicles of the last 20 years or so. All three had the "air bypass" valve too. I do not know what you mean with "ISC system". BTW, I have known some discreet electronic components that have failed due to being used too near the maximun demand for too long, would you not consider that to be 'wearing out' ?? Best wishes David --- news://freenews.netfront.net/ - complaints: news(a)netfront.net ---
From: DAS on 8 Mar 2010 05:49 "I looked it up". Could one or both of you provide a URL for us to follow? Gelling -- not "jelling"... :-) -- or ice formation... would like to read up, as I was under the impression from the brief reports I heard on the general news that it was diesel gelling, but that might just have been my dodgy memory... DAS To reply directly replace 'nospam' with 'schmetterling' -- "News" <News(a)Groups.Name> wrote in message news:pKSdnRReuqPLGQnWnZ2dnUVZ_rOdnZ2d(a)speakeasy.net... > clare(a)snyder.on.ca wrote: >> On Sun, 07 Mar 2010 18:05:07 -0500, News <News(a)Groups.Name> wrote: >> >>> clare(a)snyder.on.ca wrote: >>>> On Sun, 7 Mar 2010 11:10:20 -0800, "theref" <theref(a)seanet.com> wrote: >>>> >>>>> "Grumpy AuContraire" <GrumpyOne(a)GrumpyvilleNOT.com> wrote in message >>>>> news:99adnZJAetdSdQ7WnZ2dnUVZ_qidnZ2d(a)giganews.com... >>>>>> bjn wrote: >>>>>>> On Sat, 06 Mar 2010 10:38:19 -0500, Bill Putney <bptn(a)kinez.net> >>>>>>> wrote: >>>>>>> >>>>>>>> jim beam wrote: >>>>>>>>> if you buy all this fear-mongering idiocy that electronic throttle >>>>>>>>> is a problem, and that brakes, transmissions and ignition kill >>>>>>>>> switches can all simultaneously fail causing a driver to lose >>>>>>>>> control, it might be worth auto manufacturers of all stripes to >>>>>>>>> adopt a slightly different implementation of electronic throttle >>>>>>>>> [e.t.] - if not for mechanical reasons, but to shut the idiots >>>>>>>>> up... >>>>>>>> The lawyers, politicians, and news media can convince the public of >>>>>>>> the impossible (failure even a totally fail safe system) any time >>>>>>>> they decide to do it depending on political or monetary motivation. >>>>>>>> IOW - the people and companies who do a good job of designing are >>>>>>>> going to get punished anyway (unless they know how to play the game >>>>>>>> in a corrupt system). There are people in our society whose life >>>>>>>> goal is to make sure that that happens. >>>>>>> The problem is that now lawyers, politicians and news media are >>>>>>> driving (no >>>>>>> pun intended) solution. The way I see them talking, cars will wind >>>>>>> up with >>>>>>> a fail-safe throttle that is more fail-safe than the controls of a >>>>>>> jumbo >>>>>>> passenger jet. >>>>>>> >>>>>> I'm not sure about this but for sure... The causes you cite >>>>>> certainly contributed in getting to where we're at! >>>>>> >>>>>> Oh, don't forget that little incident when a B-777's engines went to >>>>>> idle about a minute before touch down at Heathrow about a year ago. >>>>>> Aircraft was totaled but there were no major injuries. >>>>>> >>>>>> Cause has been assessed to software/computer glitch. >>>>>> >>>>>> JT >>>>> I believe that was traced to icing in the fuel system. SOP now is to >>>>> cycle fuel after prolonged low temp at altitude. >>>> Icing on a JET????????? >>>> Don't think so. >>> >>> Absolutely. Determined to be cause of BA 777 landing short at Heathrow. >> OK - I looked it up. Technically this was fuel jelling - common with >> diesel fuel in arctic conditions. In the case of the Rolls turbines, >> it was a design fault in the fuel pre-heater unit which resulted in a >> mandatory replacement with a redesigned heat exchanger. >> >> Different than the carb icing on a prop plane. > > It was ice in the fuel blocking the pre-heater, not fuel jelling. Get it > straight.
From: Bill Putney on 8 Mar 2010 06:14 clare(a)snyder.on.ca wrote: > On Sun, 07 Mar 2010 18:29:44 -0500, Bill Putney <bptn(a)kinez.net> >> Actually, after some thought, I can see how it might be done with a >> single pot: Pot wiper gets tied to ground, and you run constant current >> into each end terminal. The voltages read at the two end terminals will >> be inverse of each other (as wiper is moved in one direction, voltage of >> one end terminal goes from 0 to R x I, voltage of the other end goes in >> the opposite direction). >> >> Not saying that the designers would have realized that it could be done >> like that, but that's the only way I could think of using a single pot. > That works too. But my way violates the unacceptable ground on an analog input that you pointed out. Your method is better. BUT - you wouldn't even have to raise the ref and its ground. Kind of combine our two methods: Tie the wiper to the ref. voltage (gets rid of the ground issue), and put a constant current source (sinking) on both ends. Scale your constant current and size your pot. such that when the wiper is pegged to one end (and reading 5 volts), the voltage on the other end is, say, 1 volt. That could be done with a nominal 8 mA current source and 500 ohm pot, as an example. The two ends would range between 1 and 5 volts (nominal), and be inverse of each other. One check the ECM could do is verify that the two voltages at any moment in time add up to 6 volts. -- Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')
From: Bill Putney on 8 Mar 2010 06:27 jim beam wrote: > /if/ the driver has pressed and released the pedal a couple of times. > why they would do that though is something i don't follow. You know, Jim - it boils down to this - you think you can predict how a human being is going to react when faced with a sudden emergency when they have never given a nano-seconds thought in the past or been trained to deal with that particular said emergency. That's ludicrous. The person will be experimenting using a brain that is in panic mode and doesn't understand or can't think fast enough to properly analyze the the ramifications of the tools (shifter, etc.) available to them at the moment to save their own life. Hands with bullet holes in them when being shot - yeah - makes a lot of sense - but that's the same kind of "irrational" reaction you get when the brain is overloaded and startled. -- Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')
From: News on 8 Mar 2010 09:10
http://www.independent.co.uk/news/uk/home-news/ice-probable-cause-of-boeing-777-crash-1893650.html DAS wrote: > "I looked it up". > > Could one or both of you provide a URL for us to follow? > > Gelling -- not "jelling"... :-) -- or ice formation... would like to read > up, as I was under the impression from the brief reports I heard on the > general news that it was diesel gelling, but that might just have been my > dodgy memory... > > DAS > > To reply directly replace 'nospam' with 'schmetterling' > -- > "News" <News(a)Groups.Name> wrote in message > news:pKSdnRReuqPLGQnWnZ2dnUVZ_rOdnZ2d(a)speakeasy.net... >> clare(a)snyder.on.ca wrote: >>> On Sun, 07 Mar 2010 18:05:07 -0500, News <News(a)Groups.Name> wrote: >>> >>>> clare(a)snyder.on.ca wrote: >>>>> On Sun, 7 Mar 2010 11:10:20 -0800, "theref" <theref(a)seanet.com> wrote: >>>>> >>>>>> "Grumpy AuContraire" <GrumpyOne(a)GrumpyvilleNOT.com> wrote in message >>>>>> news:99adnZJAetdSdQ7WnZ2dnUVZ_qidnZ2d(a)giganews.com... >>>>>>> bjn wrote: >>>>>>>> On Sat, 06 Mar 2010 10:38:19 -0500, Bill Putney <bptn(a)kinez.net> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> jim beam wrote: >>>>>>>>>> if you buy all this fear-mongering idiocy that electronic throttle >>>>>>>>>> is a problem, and that brakes, transmissions and ignition kill >>>>>>>>>> switches can all simultaneously fail causing a driver to lose >>>>>>>>>> control, it might be worth auto manufacturers of all stripes to >>>>>>>>>> adopt a slightly different implementation of electronic throttle >>>>>>>>>> [e.t.] - if not for mechanical reasons, but to shut the idiots >>>>>>>>>> up... >>>>>>>>> The lawyers, politicians, and news media can convince the public of >>>>>>>>> the impossible (failure even a totally fail safe system) any time >>>>>>>>> they decide to do it depending on political or monetary motivation. >>>>>>>>> IOW - the people and companies who do a good job of designing are >>>>>>>>> going to get punished anyway (unless they know how to play the game >>>>>>>>> in a corrupt system). There are people in our society whose life >>>>>>>>> goal is to make sure that that happens. >>>>>>>> The problem is that now lawyers, politicians and news media are >>>>>>>> driving (no >>>>>>>> pun intended) solution. The way I see them talking, cars will wind >>>>>>>> up with >>>>>>>> a fail-safe throttle that is more fail-safe than the controls of a >>>>>>>> jumbo >>>>>>>> passenger jet. >>>>>>>> >>>>>>> I'm not sure about this but for sure... The causes you cite >>>>>>> certainly contributed in getting to where we're at! >>>>>>> >>>>>>> Oh, don't forget that little incident when a B-777's engines went to >>>>>>> idle about a minute before touch down at Heathrow about a year ago. >>>>>>> Aircraft was totaled but there were no major injuries. >>>>>>> >>>>>>> Cause has been assessed to software/computer glitch. >>>>>>> >>>>>>> JT >>>>>> I believe that was traced to icing in the fuel system. SOP now is to >>>>>> cycle fuel after prolonged low temp at altitude. >>>>> Icing on a JET????????? >>>>> Don't think so. >>>> Absolutely. Determined to be cause of BA 777 landing short at Heathrow. >>> OK - I looked it up. Technically this was fuel jelling - common with >>> diesel fuel in arctic conditions. In the case of the Rolls turbines, >>> it was a design fault in the fuel pre-heater unit which resulted in a >>> mandatory replacement with a redesigned heat exchanger. >>> >>> Different than the carb icing on a prop plane. >> It was ice in the fuel blocking the pre-heater, not fuel jelling. Get it >> straight. > > |