On 3/7/2005 11:00 PM jim beam spake these words of knowledge:

> David and Tracey Mills wrote:
>> jim beam wrote:
>>
>>
>>>David and Tracey Mills wrote:
>>>
>>>>Well for starters, if the engine is multi-point injected, then you
>>>>wouldn't be injecting fuel into a throttle......
>>>
>>>is doesn't matter the location of the injectors - you still have a
>>>throttle on any gasoline engine to control air flow. even "fly by wire"
>>>gasoline engines use throttles.
>>>
>>>
>>>>it would be injected
>>>>into the intake manifold behind the intake valve. So, if the injectors
>>>>"shut
>>>>off" while coasting, does that mean when you are accelerating in a
>>>>manual trans car that the injectors are "shut off" while changing gears
>>>>?
>>>
>>>they shut off while coasting, i.e. if you take your foot off the gas on
>>>a down grade, slowing down, etc. the map conditions are typically rpm's
>>>over 2k, speed over 30mph, but it varies with different cars.
>>>
>>>
>>>>I would be inclined to think that instead of the injectors being "shut
>>>>
>>>>off", the pulse width of the injectors would be shortened. Watching a
>>>>scan tool (set on injector pulse width display ) while driving, or even
>>>>just racing an engine at idle, would show you that the injectors are not
>>>>
>>>>shut off.
>>>
>>>my analyzer doesn't show zero pulse width either, but then it doesn't
>>>store thousands of points to allow for individual pulse inspection.
>>>besides, you'll almost never see fully shut off injectors while you have
>>>the motor in the workshop.
>>>
>>>if you want an example of basic injection systems, including cut-off,
>>>check out:
>>>http://www.nightrider.com/biketech/e...ect_manual.htm
>>>but there's a ton of books & other stuff out there about how these
>>>things work.
>>>
>>>also worth checking out is:
>>>http://www.bgsoflex.com/megasquirt.html if you want to roll your own system.
>>>
>>>
>>>>D.Mills - Licensed Automotive Technician.
>>>>
>>
>>
>> Well, we'll have to agree to disagree !! I've seen the evidence on hundreds of
>> cars (mainly Hyundai and Nissan.....Hyundai data is actually faster out of the
>> scanner than Nissan) and have had many courses about injection architecture and
>> operation, and I have to work with what I have learned and what I observe in
>> reality every day.
>>
>> D.Mills - Licensed Automotive Technician.
>>
>>
> i don't think this is a "agree to disagree" issue - this is about the
> service tech saying they know more about a system than the guys that
> built the stuff in the first place - which is highly unlikely - and
> /then/ shutting the book as if there's nothing more to be learned on the
> subject.
>
> ignorance is temporary. willful ignorance is not.

Jim, I'm confused. As I see it, David here is a service tech. He's
saying that the book & classes he has taken in his profession, as well
as his professional experience, tell him that the injectors in fact do
not altogether shut off. Who are the guys who built the stuff in the
first place in this disagreement, and what is their take on the issue?
Note that I have no idea whatsoever who's right, and make no claim to.

RFT!!!
Dave Kelsen
--
.... I asked Mom if I was a gifted child... she said they certainly
wouldn't have paid for me.

 

On 3/7/2005 11:00 PM jim beam spake these words of knowledge:

> David and Tracey Mills wrote:
>> jim beam wrote:
>>
>>
>>>David and Tracey Mills wrote:
>>>
>>>>Well for starters, if the engine is multi-point injected, then you
>>>>wouldn't be injecting fuel into a throttle......
>>>
>>>is doesn't matter the location of the injectors - you still have a
>>>throttle on any gasoline engine to control air flow. even "fly by wire"
>>>gasoline engines use throttles.
>>>
>>>
>>>>it would be injected
>>>>into the intake manifold behind the intake valve. So, if the injectors
>>>>"shut
>>>>off" while coasting, does that mean when you are accelerating in a
>>>>manual trans car that the injectors are "shut off" while changing gears
>>>>?
>>>
>>>they shut off while coasting, i.e. if you take your foot off the gas on
>>>a down grade, slowing down, etc. the map conditions are typically rpm's
>>>over 2k, speed over 30mph, but it varies with different cars.
>>>
>>>
>>>>I would be inclined to think that instead of the injectors being "shut
>>>>
>>>>off", the pulse width of the injectors would be shortened. Watching a
>>>>scan tool (set on injector pulse width display ) while driving, or even
>>>>just racing an engine at idle, would show you that the injectors are not
>>>>
>>>>shut off.
>>>
>>>my analyzer doesn't show zero pulse width either, but then it doesn't
>>>store thousands of points to allow for individual pulse inspection.
>>>besides, you'll almost never see fully shut off injectors while you have
>>>the motor in the workshop.
>>>
>>>if you want an example of basic injection systems, including cut-off,
>>>check out:
>>>http://www.nightrider.com/biketech/e...ect_manual.htm
>>>but there's a ton of books & other stuff out there about how these
>>>things work.
>>>
>>>also worth checking out is:
>>>http://www.bgsoflex.com/megasquirt.html if you want to roll your own system.
>>>
>>>
>>>>D.Mills - Licensed Automotive Technician.
>>>>
>>
>>
>> Well, we'll have to agree to disagree !! I've seen the evidence on hundreds of
>> cars (mainly Hyundai and Nissan.....Hyundai data is actually faster out of the
>> scanner than Nissan) and have had many courses about injection architecture and
>> operation, and I have to work with what I have learned and what I observe in
>> reality every day.
>>
>> D.Mills - Licensed Automotive Technician.
>>
>>
> i don't think this is a "agree to disagree" issue - this is about the
> service tech saying they know more about a system than the guys that
> built the stuff in the first place - which is highly unlikely - and
> /then/ shutting the book as if there's nothing more to be learned on the
> subject.
>
> ignorance is temporary. willful ignorance is not.

Jim, I'm confused. As I see it, David here is a service tech. He's
saying that the book & classes he has taken in his profession, as well
as his professional experience, tell him that the injectors in fact do
not altogether shut off. Who are the guys who built the stuff in the
first place in this disagreement, and what is their take on the issue?
Note that I have no idea whatsoever who's right, and make no claim to.

RFT!!!
Dave Kelsen
--
.... I asked Mom if I was a gifted child... she said they certainly
wouldn't have paid for me.

 

Dave Kelsen wrote:
> On 3/7/2005 11:00 PM jim beam spake these words of knowledge:
>
>> David and Tracey Mills wrote:
>>
>>> jim beam wrote:
>>>
>>>
>>>> David and Tracey Mills wrote:
>>>>
>>>>> Well for starters, if the engine is multi-point injected, then you
>>>>> wouldn't be injecting fuel into a throttle......
>>>>
>>>>
>>>> is doesn't matter the location of the injectors - you still have a
>>>> throttle on any gasoline engine to control air flow. even "fly by
>>>> wire"
>>>> gasoline engines use throttles.
>>>>
>>>>
>>>>> it would be injected
>>>>> into the intake manifold behind the intake valve. So, if the injectors
>>>>> "shut
>>>>> off" while coasting, does that mean when you are accelerating in a
>>>>> manual trans car that the injectors are "shut off" while changing
>>>>> gears
>>>>> ?
>>>>
>>>>
>>>> they shut off while coasting, i.e. if you take your foot off the gas on
>>>> a down grade, slowing down, etc. the map conditions are typically
>>>> rpm's
>>>> over 2k, speed over 30mph, but it varies with different cars.
>>>>
>>>>
>>>>> I would be inclined to think that instead of the injectors being "shut
>>>>>
>>>>> off", the pulse width of the injectors would be shortened. Watching a
>>>>> scan tool (set on injector pulse width display ) while driving, or
>>>>> even
>>>>> just racing an engine at idle, would show you that the injectors
>>>>> are not
>>>>>
>>>>> shut off.
>>>>
>>>>
>>>> my analyzer doesn't show zero pulse width either, but then it doesn't
>>>> store thousands of points to allow for individual pulse inspection.
>>>> besides, you'll almost never see fully shut off injectors while you
>>>> have
>>>> the motor in the workshop.
>>>>
>>>> if you want an example of basic injection systems, including cut-off,
>>>> check out:
>>>> http://www.nightrider.com/biketech/e...ect_manual.htm
>>>> but there's a ton of books & other stuff out there about how these
>>>> things work.
>>>>
>>>> also worth checking out is:
>>>> http://www.bgsoflex.com/megasquirt.html if you want to roll your own
>>>> system.
>>>>
>>>>
>>>>> D.Mills - Licensed Automotive Technician.
>>>>>
>>>
>>>
>>> Well, we'll have to agree to disagree !! I've seen the evidence on
>>> hundreds of
>>> cars (mainly Hyundai and Nissan.....Hyundai data is actually faster
>>> out of the
>>> scanner than Nissan) and have had many courses about injection
>>> architecture and
>>> operation, and I have to work with what I have learned and what I
>>> observe in
>>> reality every day.
>>>
>>> D.Mills - Licensed Automotive Technician.
>>>
>>>
>> i don't think this is a "agree to disagree" issue - this is about the
>> service tech saying they know more about a system than the guys that
>> built the stuff in the first place - which is highly unlikely - and
>> /then/ shutting the book as if there's nothing more to be learned on
>> the subject.
>>
>> ignorance is temporary. willful ignorance is not.
>
>
> Jim, I'm confused. As I see it, David here is a service tech. He's
> saying that the book & classes he has taken in his profession, as well
> as his professional experience, tell him that the injectors in fact do
> not altogether shut off. Who are the guys who built the stuff in the
> first place in this disagreement, and what is their take on the issue?
> Note that I have no idea whatsoever who's right, and make no claim to.
>
> RFT!!!
> Dave Kelsen

the guys that built the stuff are like those cited in my links. check
the megasquirt code:

** If (RPM > 15 (corresponding to 1500 RPM)) then (fuel cut mode):
** {
** 1) Set TPSACCEL value to TPSDQ
** 2) Set TPSDEN bit in ENGINE
** 3) Go to EGO Delta Step Check Section
** }

or buy something like the bosch automotive handbook.

if i appear rude to d.mills, i apologize for my tone, but not my
content. i've no disrespect for service techs, heck, i even qualified
as one too, but having done a whole bunch of engineering & electronics
before hand, i can tell you authoritatively that the stuff taught at the
technician level is somewhat absent the same detail used at the systems
design & engineering level.

 

Dave Kelsen wrote:
> On 3/7/2005 11:00 PM jim beam spake these words of knowledge:
>
>> David and Tracey Mills wrote:
>>
>>> jim beam wrote:
>>>
>>>
>>>> David and Tracey Mills wrote:
>>>>
>>>>> Well for starters, if the engine is multi-point injected, then you
>>>>> wouldn't be injecting fuel into a throttle......
>>>>
>>>>
>>>> is doesn't matter the location of the injectors - you still have a
>>>> throttle on any gasoline engine to control air flow. even "fly by
>>>> wire"
>>>> gasoline engines use throttles.
>>>>
>>>>
>>>>> it would be injected
>>>>> into the intake manifold behind the intake valve. So, if the injectors
>>>>> "shut
>>>>> off" while coasting, does that mean when you are accelerating in a
>>>>> manual trans car that the injectors are "shut off" while changing
>>>>> gears
>>>>> ?
>>>>
>>>>
>>>> they shut off while coasting, i.e. if you take your foot off the gas on
>>>> a down grade, slowing down, etc. the map conditions are typically
>>>> rpm's
>>>> over 2k, speed over 30mph, but it varies with different cars.
>>>>
>>>>
>>>>> I would be inclined to think that instead of the injectors being "shut
>>>>>
>>>>> off", the pulse width of the injectors would be shortened. Watching a
>>>>> scan tool (set on injector pulse width display ) while driving, or
>>>>> even
>>>>> just racing an engine at idle, would show you that the injectors
>>>>> are not
>>>>>
>>>>> shut off.
>>>>
>>>>
>>>> my analyzer doesn't show zero pulse width either, but then it doesn't
>>>> store thousands of points to allow for individual pulse inspection.
>>>> besides, you'll almost never see fully shut off injectors while you
>>>> have
>>>> the motor in the workshop.
>>>>
>>>> if you want an example of basic injection systems, including cut-off,
>>>> check out:
>>>> http://www.nightrider.com/biketech/e...ect_manual.htm
>>>> but there's a ton of books & other stuff out there about how these
>>>> things work.
>>>>
>>>> also worth checking out is:
>>>> http://www.bgsoflex.com/megasquirt.html if you want to roll your own
>>>> system.
>>>>
>>>>
>>>>> D.Mills - Licensed Automotive Technician.
>>>>>
>>>
>>>
>>> Well, we'll have to agree to disagree !! I've seen the evidence on
>>> hundreds of
>>> cars (mainly Hyundai and Nissan.....Hyundai data is actually faster
>>> out of the
>>> scanner than Nissan) and have had many courses about injection
>>> architecture and
>>> operation, and I have to work with what I have learned and what I
>>> observe in
>>> reality every day.
>>>
>>> D.Mills - Licensed Automotive Technician.
>>>
>>>
>> i don't think this is a "agree to disagree" issue - this is about the
>> service tech saying they know more about a system than the guys that
>> built the stuff in the first place - which is highly unlikely - and
>> /then/ shutting the book as if there's nothing more to be learned on
>> the subject.
>>
>> ignorance is temporary. willful ignorance is not.
>
>
> Jim, I'm confused. As I see it, David here is a service tech. He's
> saying that the book & classes he has taken in his profession, as well
> as his professional experience, tell him that the injectors in fact do
> not altogether shut off. Who are the guys who built the stuff in the
> first place in this disagreement, and what is their take on the issue?
> Note that I have no idea whatsoever who's right, and make no claim to.
>
> RFT!!!
> Dave Kelsen

the guys that built the stuff are like those cited in my links. check
the megasquirt code:

** If (RPM > 15 (corresponding to 1500 RPM)) then (fuel cut mode):
** {
** 1) Set TPSACCEL value to TPSDQ
** 2) Set TPSDEN bit in ENGINE
** 3) Go to EGO Delta Step Check Section
** }

or buy something like the bosch automotive handbook.

if i appear rude to d.mills, i apologize for my tone, but not my
content. i've no disrespect for service techs, heck, i even qualified
as one too, but having done a whole bunch of engineering & electronics
before hand, i can tell you authoritatively that the stuff taught at the
technician level is somewhat absent the same detail used at the systems
design & engineering level.