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03-01-2009, 09:55 PM | #1 |
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Car: astina BA 1997 1.8Ltr
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Timing advance
hi guys, does any one know how the timing is advanced by the ECU on BA 1997 1.8L engine.????
Its not Vacuum advanced..... |
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03-01-2009, 10:07 PM | #2 |
コスモ
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The timing will be mapped against engine speed and load (RPM, throttle possition, air flow). Base timing can be changed easily enough though.
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04-01-2009, 08:48 AM | #3 |
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but how does the ECU physically change the timing , since there is a dizy there must be a way as to how the ECU alter the timing according to load and engine speed
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04-01-2009, 09:12 AM | #4 |
コスモ
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In short the ECU de-energises the coil to create the spark based on a signal from a sensor in the distributor (crank angle sensor on V6) and load.
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04-01-2009, 09:25 AM | #5 |
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thanks cosmo!
The reason I asked is, when I adjust the base idle (800 RPM) & timing (12 BTDC) by shorting TEN & GND its all good , but when I remove the jumper (TEN & GND) the timing retards to 0 or even lower together with idle speed |
04-01-2009, 07:52 PM | #6 |
コスモ
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If you had vac advance then you'd pull the vac before setting the timing. Once you re-attached the vac you'd have the same issue.
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04-01-2009, 08:43 PM | #7 |
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there is no vac advance system on BA!
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04-01-2009, 09:31 PM | #8 |
コスモ
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No it doesn't and idle doesn't reflect base setting either.
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04-01-2009, 10:49 PM | #9 |
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well that's what I thought too! but it seem to be reflecting the base timing. cause if I set base idle to 650rpm and remove the jumper wire, the timing stays at 10-12 BTDC. Anything above 650rpm, timing retards!
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