Quote:
Originally Posted by thambu19
Id think 4-6% LFTF isnt a concern at CL but at OL yes maybe. Some ppl tried going 100% DI at loads above 0.7 for knock relief they also said their fuel trims went up. I am wondering if it is because at 100% DI vs earlier 50% DI the charge cooling is increasing the VE and hence the LTFT. If that is the case the engine should run the same AFR at OL as before. Since you said the LFTF increased and made the engine run Rich in OL id suspect that the LTFT was not supposed to go positive but did due to PW not scaling appropriately with PFI/DI ratio change.
Those who have had this issue can you chime in?
Did you see higher LTFT in areas where you increased PFI or in areas where you increased DI?
The LTFT learnt at low loads should not affect OL. Usually it is the LTFT just below OL that gets carried into OL. So if the idle LTFT is off nothing to worry there, atleast not so much
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While running 100% Pi after having dialed my MAF for full DI I've found that at the lower MAF ranges 0~1.7v fuel trims will go up about 7~8% on average. AT 1.9~2.0 it fule trims go up about 4%. Then 2.1~3.0v, fuel trim ramp up to +10% with my scaling. I ended up subtracting 5% from the port injector scale value and find this is a good compromise. I may try to subtract 6% if I'm not happy with the result (being anal), but so far I think this works well.