how does the individual cylinder fuel trim work?

tinkerbell · Post by **tinkerbell** » Thu Feb 17, 2011 4:07 am

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...

Johnny_9 · Post by **Johnny_9** » Thu Feb 17, 2011 7:38 am

valve seal? oil leak?

Post by **Spunkster** » Thu Feb 17, 2011 10:19 am

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.

tinkerbell · Post by **tinkerbell** » Thu Feb 17, 2011 3:20 pm

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...)