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| Big emissions problems on my '90 Geo Metro | |
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| Tweet Topic Started: Jun 16 2010, 09:21 AM (4,795 Views) | |
| mwebb | Jun 21 2010, 11:55 PM Post #31 |
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FOG
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Woodie may be able to trick his system into advancing the timing ... some by lowering supply voltage to the MAP sensor , from 5 volts to a little less . which would lower the MAP value , which would , decrease Engine load and injector pulse width the feedback system with the 02 sensor would correct for IPW and maintain mixture at stoich , using FT correction s. but decreased engine load would also result in slightly greater ignition timing advance. so Woodie could trick his system into advancing the ign timing , as long as he did not reduce MAP supply so low that the system exceeded + 25% LTFT then we could see if advancing ignition timing on the 1998 G13 has a positive effect on FE .... it would reduce MAX power unless a 5 pin relay were used to only reduce MAP supply when the EGR was active .... or the same relay could be used to apply reduced voltage to MAP at anything other than WOT , using the TPS for a control signal hint hint,wink wink Edited by mwebb, Jun 21 2010, 11:58 PM.
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7:39 PM Jul 10