Injector Opening times

This might be asking a bit much but does anyone have any specs on the
stock toyota injector opening times for the 3sgte?

Ta!
James

"Coyoteboy" <coyoteboyuk@hotmail.com> wrote in message
news:1165266040.594364.179110@80g2000cwy.googlegroups.com...[color=blue]
> This might be asking a bit much but does anyone have any specs on the
> stock toyota injector opening times for the 3sgte?
>
> Ta!
> James
>[/color]

I do not recall ever seeing a specification for injector opening times,
probably because injector opening times vary with coolant temp, MAF/MAP
sensor output, O2 sensor output, throttle position sensor output, crankshaft
position sensor output, and engine RPM. With all those possible
permutations, it would be difficult to come up with a "stock" opening time.
--

Ray O
(correct punctuation to reply)

Ray O wrote:[color=blue]
> I do not recall ever seeing a specification for injector opening times,
> probably because injector opening times vary with coolant temp, MAF/MAP
> sensor output, O2 sensor output, throttle position sensor output, crankshaft
> position sensor output, and engine RPM. With all those possible
> permutations, it would be difficult to come up with a "stock" opening time.[/color]

Sorry i mis-represented my question - by opening time i meant "time
between current applied to fuel delivery", not calculated pulsewidth.
Low impedance injectors tend to take 0.7ms to 0.9ms to open and high
impedence ~0.9-1.1, depending on flow rate and current/voltage control
method. The 3S-GTE injectors are low impedance and have a series
resistor. For normal tuning its not a problem - so long as you tune to
a specific AFR you dont have to worry about the opening time as its
fairly constant but as you approach idle, if the opening time you have
programmed into your ECU is significantly inaccurate the adjustment of
the VE table becomes a lot harder. For example if you have your
injector opening time set to 1ms but your injector opens in 0.8ms,
even if you drop your VE to 0 you still get some fuel delivered - this
effect means that at low VEs your tunability goes out of the window.

I have tuned my car at cruise and under-hoof but at idle im at 12:1
AFRs and i cant seem to make it go lower by adjusting VE bins - hence
the actual opening times are probably shorter than i have set, but id
like to know for sure. I have scanned the net for hours and not found
the info and even between two similar makes/models there can be large
variations of opening time. Toyota look at me like im some sort of
lunatic when i ask, as i suspected!

James

"Coyoteboy" <coyoteboyuk@hotmail.com> wrote in message
news:1165271993.522415.156290@16g2000cwy.googlegroups.com...[color=blue]
>
> Ray O wrote:[color=green]
>> I do not recall ever seeing a specification for injector opening times,
>> probably because injector opening times vary with coolant temp, MAF/MAP
>> sensor output, O2 sensor output, throttle position sensor output,
>> crankshaft
>> position sensor output, and engine RPM. With all those possible
>> permutations, it would be difficult to come up with a "stock" opening
>> time.[/color]
>
> Sorry i mis-represented my question - by opening time i meant "time
> between current applied to fuel delivery", not calculated pulsewidth.
> Low impedance injectors tend to take 0.7ms to 0.9ms to open and high
> impedence ~0.9-1.1, depending on flow rate and current/voltage control
> method. The 3S-GTE injectors are low impedance and have a series
> resistor. For normal tuning its not a problem - so long as you tune to
> a specific AFR you dont have to worry about the opening time as its
> fairly constant but as you approach idle, if the opening time you have
> programmed into your ECU is significantly inaccurate the adjustment of
> the VE table becomes a lot harder. For example if you have your
> injector opening time set to 1ms but your injector opens in 0.8ms,
> even if you drop your VE to 0 you still get some fuel delivered - this
> effect means that at low VEs your tunability goes out of the window.
>
> I have tuned my car at cruise and under-hoof but at idle im at 12:1
> AFRs and i cant seem to make it go lower by adjusting VE bins - hence
> the actual opening times are probably shorter than i have set, but id
> like to know for sure. I have scanned the net for hours and not found
> the info and even between two similar makes/models there can be large
> variations of opening time. Toyota look at me like im some sort of
> lunatic when i ask, as i suspected!
>
> James
>[/color]

I thought that was an odd question for you to ask, and I had thought to ask
if you meant injector pulse duration or something else.

AFAIK, there are only 2 places where the info you seek might be published
where the public has access - the factory repair manual, and the service
training department's new model intro course for dealership technicians for
the year that particular engine was first sold, although I doubt if that
information is included in either of those sources. That info was not even
widely available internally at Toyota. I've seen that stuff published for
use by product engineers and field product engineers, but that stuff was
supposed to be top secret, mainly to make it more difficult for competitors
to "reverse engineer" something.

I'll try to remember to take a look at a factory service manual and see if
the info is included in the ones I have.
--

Ray O
(correct punctuation to reply)

On Mon, 04 Dec 2006 14:39:53 -0800, Coyoteboy wrote:
[color=blue]
>
> Ray O wrote:[color=green]
>> I do not recall ever seeing a specification for injector opening times,
>> probably because injector opening times vary with coolant temp, MAF/MAP
>> sensor output, O2 sensor output, throttle position sensor output, crankshaft
>> position sensor output, and engine RPM. With all those possible
>> permutations, it would be difficult to come up with a "stock" opening time.[/color]
>
> Sorry i mis-represented my question - by opening time i meant "time
> between current applied to fuel delivery", not calculated pulsewidth.
> Low impedance injectors tend to take 0.7ms to 0.9ms to open and high
> impedence ~0.9-1.1, depending on flow rate and current/voltage control
> method. The 3S-GTE injectors are low impedance and have a series
> resistor. For normal tuning its not a problem - so long as you tune to
> a specific AFR you dont have to worry about the opening time as its
> fairly constant but as you approach idle, if the opening time you have
> programmed into your ECU is significantly inaccurate the adjustment of
> the VE table becomes a lot harder. For example if you have your
> injector opening time set to 1ms but your injector opens in 0.8ms,
> even if you drop your VE to 0 you still get some fuel delivered - this
> effect means that at low VEs your tunability goes out of the window.
>
> I have tuned my car at cruise and under-hoof but at idle im at 12:1
> AFRs and i cant seem to make it go lower by adjusting VE bins - hence
> the actual opening times are probably shorter than i have set, but id
> like to know for sure. I have scanned the net for hours and not found
> the info and even between two similar makes/models there can be large
> variations of opening time. Toyota look at me like im some sort of
> lunatic when i ask, as i suspected![/color]

Ya, and from reading the above, that's understandable!
Now, I don't get too much into tuning. What is the purpose of getting this
specific?
[color=blue]
>
> James[/color]

wouldn't that number depend on throttle opening, water temp, barometric
pressure,
inlet air temp and rpm?
sammm

--

"Coyoteboy" <coyoteboyuk@hotmail.com> wrote in message
news:1165266040.594364.179110@80g2000cwy.googlegroups.com...[color=blue]
> This might be asking a bit much but does anyone have any specs on the
> stock toyota injector opening times for the 3sgte?
>
> Ta!
> James
>[/color]

Hachiroku ãƒ?ãƒ?ãƒ*ク wrote:[color=blue]
> Ya, and from reading the above, that's understandable!
> Now, I don't get too much into tuning. What is the purpose of getting this
> specific?[/color]

I have an idle tuning problem on my megasquirt and im fairly sure its
due to my specified opening time being incorrect for my injectors.
Trial and error could find it approximately but id rather get it
bang-on, also so i can switch between single and multiple squirts per
cycle (engine runs much smoother at 4 squirts per cycle but the whole
fuelling needs scaling every time due to injector times being wrong).
The closer i can get to OEM setup the better i can push the upper end
"safely".

SAMMM wrote:[color=blue]
> wouldn't that number depend on throttle opening, water temp, barometric
> pressure,
> inlet air temp and rpm?
> sammm[/color]

Badly worded, sorry, check my reply to Ray O.

Ta
J

Ray O wrote:[color=blue]
> I'll try to remember to take a look at a factory service manual and see if
> the info is included in the ones I have.
> --
>
> Ray O
> (correct punctuation to reply)[/color]

Cheers for that Ray, I suspect it wont be there but it'd be handy if it
was!

I suspect the only way i will be able to determine it is using a
current probe on an oscilloscope to watch the current flow as it opens
- it should plateau as it hits "open" i think.

J

"Coyoteboy" <coyoteboyuk@hotmail.com> wrote in message
news:1165285506.813787.287490@j72g2000cwa.googlegroups.com...[color=blue]
>
> Ray O wrote:[color=green]
>> I'll try to remember to take a look at a factory service manual and see
>> if
>> the info is included in the ones I have.
>> --
>>
>> Ray O
>> (correct punctuation to reply)[/color]
>
> Cheers for that Ray, I suspect it wont be there but it'd be handy if it
> was!
>
> I suspect the only way i will be able to determine it is using a
> current probe on an oscilloscope to watch the current flow as it opens
> - it should plateau as it hits "open" i think.
>
> J
>[/color]

I checked the factory service manual for a 1997 Avalon, and the spec you are
looking for is not listed. It does show pulse duration at idle for that
car, which is a hair over 2 m seconds but not the opening time. All they
show is a graph with a picture of what the waveform should look like on a
scope, and yes, it does plateau when open. Unfortunately, they only show
the pattern for all of the injectors on a 100 m second scale and an expanded
view of only 1 pulse on a 1 m second scale so there is no way to even
guesstimate what the time between signal generation and injector opening is.

Sorry, it looks like it will be trial and error unless you can get a product
engineer to do the research for you and part with the info.

Good luck!
--

Ray O
(correct punctuation to reply)

Ray O wrote:[color=blue]
> I checked the factory service manual for a 1997 Avalon, and the spec you are
> looking for is not listed. It does show pulse duration at idle for that
> car, which is a hair over 2 m seconds but not the opening time. All they
> show is a graph with a picture of what the waveform should look like on a
> scope, and yes, it does plateau when open. Unfortunately, they only show
> the pattern for all of the injectors on a 100 m second scale and an expanded
> view of only 1 pulse on a 1 m second scale so there is no way to even
> guesstimate what the time between signal generation and injector opening is.
>
> Sorry, it looks like it will be trial and error unless you can get a product
> engineer to do the research for you and part with the info.
>
> Good luck!
> --
>
> Ray O
> (correct punctuation to reply)[/color]

Excellent info there thanks Ray, and I've just received an email back
from an injector repairing company who were kind enough to part with
some info. He suggested that the low impedance injectors around the
size of mine coupled with a resistor pack, such as mine is, usually
open in around 1.5 to 1.6ms. At idle that would equate to around 2ms
pulse width in total which aligns with your information nicely (I
currently have an idle total PW of 1.4 and little or no control over
fuel).

But all of this confuses me as I'm currently running rich with a total
PW of 1.4 so god only knows what its going to do when i set the
opening time to more than that! Tuning an EFI system is a lot harder
than it seems on the outset LOL!

"Coyoteboy" <coyoteboyuk@hotmail.com> wrote in message
news:1165319533.080103.169700@73g2000cwn.googlegroups.com...[color=blue]
>
> Ray O wrote:[color=green]
>> I checked the factory service manual for a 1997 Avalon, and the spec you
>> are
>> looking for is not listed. It does show pulse duration at idle for that
>> car, which is a hair over 2 m seconds but not the opening time. All they
>> show is a graph with a picture of what the waveform should look like on a
>> scope, and yes, it does plateau when open. Unfortunately, they only show
>> the pattern for all of the injectors on a 100 m second scale and an
>> expanded
>> view of only 1 pulse on a 1 m second scale so there is no way to even
>> guesstimate what the time between signal generation and injector opening
>> is.
>>
>> Sorry, it looks like it will be trial and error unless you can get a
>> product
>> engineer to do the research for you and part with the info.
>>
>> Good luck!
>> --
>>
>> Ray O
>> (correct punctuation to reply)[/color]
>
> Excellent info there thanks Ray, and I've just received an email back
> from an injector repairing company who were kind enough to part with
> some info. He suggested that the low impedance injectors around the
> size of mine coupled with a resistor pack, such as mine is, usually
> open in around 1.5 to 1.6ms. At idle that would equate to around 2ms
> pulse width in total which aligns with your information nicely (I
> currently have an idle total PW of 1.4 and little or no control over
> fuel).
>
> But all of this confuses me as I'm currently running rich with a total
> PW of 1.4 so god only knows what its going to do when i set the
> opening time to more than that! Tuning an EFI system is a lot harder
> than it seems on the outset LOL!
>[/color]

To me, tuning an EFI system is part chemistry, part electrical engineering,
and part voodoo.

I don't know if you can set opening time and pulse width independently, but
if that is possible and the AFR is already rich at idle, then if you
increase the opening time, then I would reduce injector pulse width by a
corresponding time. If you are running rich at idle, make sure that the ECU
is getting a signal from the coolant temp sensor, that the system enters
closed loop, and that the signal from #1 O2 sensor is in spec.
--

Ray O
(correct punctuation to reply)

Ray O wrote:[color=blue]
> To me, tuning an EFI system is part chemistry, part electrical engineering,
> and part voodoo.[/color]

Amen to that :)
[color=blue]
> I don't know if you can set opening time and pulse width independently, but
> if that is possible and the AFR is already rich at idle, then if you
> increase the opening time, then I would reduce injector pulse width by a
> corresponding time.[/color]

The end of the MS calculations, when you check through the assembly
code, is basically commanded_PW = opening_time + fueling_PW so
increasing the opening time will just increase the fuel - annoying!
[color=blue]
> If you are running rich at idle, make sure that the ECU
> is getting a signal from the coolant temp sensor, that the system enters
> closed loop, and that the signal from #1 O2 sensor is in spec.[/color]

Yup, running ~87C but ignoring feedback from the wideband 02 sensor for
now, it only complicates matters while tuning im afraid- i use it to
log my latest changes and adjust the fuelling accordingly- I will put
it closed-loop when i have the VEs almost bang-on so i can set its
correction parameters to low and slow to prevent surging. I'm not far
off that for the rest of the table but idle is driving me nuts!

Ta
J

"Coyoteboy" <coyoteboyuk@hotmail.com> wrote in message
news:1165336321.264728.274520@l12g2000cwl.googlegroups.com...[color=blue]
>
> Ray O wrote:[color=green]
>> To me, tuning an EFI system is part chemistry, part electrical
>> engineering,
>> and part voodoo.[/color]
>
> Amen to that :)
>[color=green]
>> I don't know if you can set opening time and pulse width independently,
>> but
>> if that is possible and the AFR is already rich at idle, then if you
>> increase the opening time, then I would reduce injector pulse width by a
>> corresponding time.[/color]
>
> The end of the MS calculations, when you check through the assembly
> code, is basically commanded_PW = opening_time + fueling_PW so
> increasing the opening time will just increase the fuel - annoying!
>[color=green]
>> If you are running rich at idle, make sure that the ECU
>> is getting a signal from the coolant temp sensor, that the system enters
>> closed loop, and that the signal from #1 O2 sensor is in spec.[/color]
>
> Yup, running ~87C but ignoring feedback from the wideband 02 sensor for
> now, it only complicates matters while tuning im afraid- i use it to
> log my latest changes and adjust the fuelling accordingly- I will put
> it closed-loop when i have the VEs almost bang-on so i can set its
> correction parameters to low and slow to prevent surging. I'm not far
> off that for the rest of the table but idle is driving me nuts!
>
> Ta
> J
>[/color]

Good luck, let us know how it turns out!


--

Ray O
(correct punctuation to reply)

Ray O wrote:[color=blue]
>
> Good luck, let us know how it turns out![/color]

Well I tried opening times from 0.4 (killed engine without leaning) to
1.6ms and nothing eased the rich mixture. I changed from 2 squirts of
all 4 injectors simultaneously to 2 squirts in banks of 2 (so
effectively from 2 squirts per cycle to 1, and lessening the pressure
drop on the rail) and i get my idle adjustment back! Woo! I'm not sure
why this makes such a difference - I'd have expected some difference
(going 2 squirts per cycle to 1 means eliminating 1 opening time from
the mis-fueling) but the difference was so great I couldnt have
expected it.

Anyway, been out tuning again and getting a really nice OEM driving
feel but with more oomph now so im grinning from ear to ear. Note to
self - save configuration somewhere it cant get lost!

Thanks for your input!
James