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how does the individual cylinder fuel trim work?

Posted: Thu Feb 17, 2011 4:07 am
by tinkerbell
does it go all across load points? i am at -10% on cylidner 2 and it is all good under WOT - but still the no.2 s.plug gets black during closed loop...

Posted: Thu Feb 17, 2011 7:38 am
by Johnny_9
valve seal? oil leak?

Posted: Thu Feb 17, 2011 10:19 am
by Spunkster
You should never need to remove 10% fuel from a single cylinder. This sounds like you have some mechanical problem with the engine. I would suggest a leakdown test to help determine where the problem is.

Posted: Thu Feb 17, 2011 3:20 pm
by tinkerbell
Spunkster wrote:You should never need to remove 10% fuel from a single cylinder. This sounds like you have some mechanical problem with the engine. I would suggest a leakdown test to help determine where the problem is.
hi - thanks, that is kinda obvious! comp test is 250 psi on all 4 cyl, but yet to do a leakdown test...

but was actually asking whether the individual fuel trim works 100% of the time at the specififed percentage?

or whether it only works under certain conditions?

(because in open loop at the race track WOT the 10% trim stops misfiring, but in closed loop around town at low throttle it fouls up...)