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View Full Version : LTFT - range vs + range lean rich question



mvvette97
September 14th, 2009, 04:52 AM
I always assumed that when the trims are running in the negative range the leaner it is and positive is richer. Is this correct or am I bassackwards?:doh2:

Aloicious
September 14th, 2009, 05:18 AM
I always assumed that when the trims are running in the negative range the leaner it is and positive is richer. Is this correct or am I bassackwards?:doh2:

bassackwards. negative LTFT's mean that the PCM is removing fuel, i.e. you're running rich, positives are the opposite. thats why when you're tuning from the trims (i.e. without a wideband), you want slightly negative trims, so you're running slightly rich, for safety.