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Forum namePerformance/Engine
Topic subjectI datalogged the 2.2L this weekend. Got a ? about the LTFT.
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=51431
51431, I datalogged the 2.2L this weekend. Got a ? about the LTFT.
Posted by Kirby, May-19-03 01:10 PM
I logged the 2.2L for the first time this weekend. I found the LTFT jumping about likt the STFT does, is this normal? It seems to be right around 10 normally which sounds right for the 10% bump in displacement. But it has varied from 0 to 17 during driving. I ran the car up to 5,000 rpm's for the first time while logging, and then started taking every gear to 5 grand, except 5th. I'm at 700 miles since the rebuild now so I figured it was ok. So what do you think about these LTFT's? The STFT jumps around like it should.
51470, RE: I datalogged the 2.2L this weekend. Got a ? about the LTFT.
Posted by Michael_97RS, May-20-03 05:00 AM
I'll know more once I start playing with my own datalogger. But it seems to me the LTFT will move less and less as time goes on, the longer it has to adjust. With only 700 miles maybe it's still jumping, because it need to level itself out. I could be completely wrong and this is just a guess.

Does it jump with rpm? or just a steady rpm it jumps around. I would think the ECU store some rpm based fuel trims also.



15.9 @ 86.7mph

Injen CAI, 55mm TB, P&P Intake, Crower Cams, Hooker Header, ERT/Catco Cat, GS-T Muffler, AFX UDP, Crane Ign Amp, S-AFC
51482, RE: I datalogged the 2.2L this weekend. Got a ? about the LTFT.
Posted by Corbin, May-20-03 07:01 AM
Since you just put in a very different motor than factory, your ECU will have to do alot of re-learning. If you are idling, then the LTFT should move very slowly. If you are driving, then it will jump all over the place. It should jump everytime you hit a new data point (throttle position, MAP, intake temp). After you hit most of the data points by driving around alot, the ECU will have to adjust the LTFT less. It will still change as you drive, but it should jump around less. Keep driving and get that thing broken in!

Corbin

'95 ESI-T
HRC+FMIC+ETC...



Gimme fuel...Gimme fire...Gimme that which I desire