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luk
Joined: 11 Jun 2004
Posts: 93
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Eric
Joined: 17 Nov 2003
Posts: 258
Location: Holland
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datsunboy
Joined: 26 Jul 2005
Posts: 209
Location: New Zealand
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 Posted: Wed Feb 22, 2006 11:37 am Post subject: |
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ok....downloaded a Mitsi rom editor...and it says that at 14V, it has a latency deadtime of 648 (usec)....which I assume is 0.648millisec?
so going by erics formula from the link you gave me...
milliSec = (latency + ((175 - Vx/0.08) * dts/256)) * 0.01
so for .648milliSec.... (latency + ((175-175) * 184/256)) *.01
all cancels out and leaves you with a latency value of 64.8dec ( or 40hex ).
is this correct?
so when changing the Injectors....you would change both the "ts/latency ( 3F8F ) and the dts ( delay coefficient.....value at 3F8E )?
I have tried working backwards with the formula to get the dts....but I get a different value each time I try a different value for the voltage and corrosponding millisec from the mitsi table.
ie at
11.68V.....0.84millisec ( i got dts of 169 )
14V.........0.648millisec
18.7V......0.456millisec ( i goto dts of 83 )
_________________
1970 Datsun 1600 CA18DET Project
The point of life is not 2 arrive at your grave all preserved & in mint condition, but 2 slide in sideways, scratched & bruised screaming F**K WHAT A RIDE!!
Last edited by datsunboy on Wed Feb 22, 2006 7:49 pm; edited 1 time in total |
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cb_drift
Joined: 04 May 2004
Posts: 472
Location: New Zealand
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| Posted: Wed Feb 22, 2006 6:38 pm Post subject: |
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i think i remember reading that the null value is from 14.7v in a nissan - but i cant remember where i saw that...
the null value is straight out ms delay
so if the injectors are 70ms latency - null should be 70(dec) or $46h
if they are 60ms latency - null should be 60(dec) or $3ch
no formula needed for them - just the outright latency... |
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datsunboy
Joined: 26 Jul 2005
Posts: 209
Location: New Zealand
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| Posted: Wed Feb 22, 2006 7:48 pm Post subject: |
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haha...turns out I already had those PDFs!
didnt realise they had null time in them
Hey lawrence....working through that formula, shows that what you said is true....a null time of 0.7millisec would be entered as 70dec or 46hex.
That formula is what the ECU uses to calculate a better null time, when the battery is NOT at 14V. ( or 14.7....whichever is correct )
_________________
1970 Datsun 1600 CA18DET Project
The point of life is not 2 arrive at your grave all preserved & in mint condition, but 2 slide in sideways, scratched & bruised screaming F**K WHAT A RIDE!! |
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