ignition timing?

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parkin10
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Post Wed Mar 07, 2012 11:01 pm

were does the ecu get its telemetry for it to know which timing map to use in any given driving condition?
sometimes my car feels a bit flat usually up hill or on the motorway
then other times it goes very well
been like it all the time i have had the car i cannot weed out this last little problem
just feels like the ecu is not responding to driver demand and advancing the timing curve
its a face lift m20b25
thanks
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Brianmoooore
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Post Wed Mar 07, 2012 11:31 pm

Maps are selected by the throttle position switch. (M42 iS engine is a little more sophisticated with a throttle position pot.)
Switch has three positions - idle, cruise and WOT (wide open throttle).
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parkin10
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Post Fri Mar 09, 2012 9:42 pm

cheers brian
so does the ecu not advance the timing opon more driver demand within the cruise part of the throttle position but before WOT?
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Brianmoooore
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Post Fri Mar 09, 2012 11:05 pm

From one end of the cruise section of the throttle position to the other has no effect on ignition timing, but the info. from the air flow meter does.
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parkin10
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Post Mon Mar 12, 2012 9:51 pm

thanks again brian
do you think theres is any thing to gain by adding a lambda sensor?
i was thinking better fueling,better economy