Ive read in maybe 2 or 3 places that our PCM's "learn" how the car runs. Im not sure how this works or what its for entirely.
My question, although backed by little understanding of the topic is:
Can you gain anything out of doing a "learn" (disconnecting the battery) after installing any set of mods? Really Im talking about power gains, versus leaving the battery connected and going on without a "learn". Would there be MPG gains?
Any insight you guys can provide on this would be great. Just something that popped into my head as im sitting here awake for 24 straight hours on 3 hours sleep.
lol im going to bed now.
thanks!
Ive found that after reflashing my ECU w/ HPT tuners and making changes, unless I cold boot the ecu by disconnecting the battery after reflash, that it usually takes a very long time for the car to start running correctly. I don't know why this is, but if I don't do this I have a lot of issues with the car stalling out once warm and running rough while cold.
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Mitsu TD06-20g |3" Downpipe w/ Cutout | 61mm Bored TB |
HP Tuners | Innovate WB02 | Spec Stage 3 | TurboTech Upper | Full Addco Sways | Sportlines & Yellows |
Our ECU's learn 2 things, spark advance, and fuel delivery. The ECU learns the fuel by using the short and long term fuel trims. It learns the knock by listening to the knock sensor and adjusting between the low octane fuel table and the high octane fuel table. When you reset the ECU it turns these learned "tables" all back to zero and it takes time for it to relearn them.
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shifted with this sort of thing should u give it some time between tuning or whats the case. like if ur dyno tuning wouldnt it be kinda screwy between runs, and wouldnt that mess with ur tune and what u end up changing?
Thanks for the info guys!
gmanz24 wrote:shifted with this sort of thing should u give it some time between tuning or whats the case. like if ur dyno tuning wouldnt it be kinda screwy between runs, and wouldnt that mess with ur tune and what u end up changing?
i would leave time in between tunes. we have found that when tuning my car and testing for gains in 0-60 times, that giving to the ECU time to reset or relearn its table has improved runing conditions such as cold starts and has actually netted better times in the 0-60. we find that usually giving it a day or two helps.
1997 RedR - ZedR
but how do u do that when ur dyno tuning, u go run after run, tune after tune. ive seen the probs with it, ya flash the car and it runs like crap. i just wish it was simpler
As for my understanding it doesn't matter in dyno tuning because your are running WOT in PE and Fuel trims aren't fed into the equation in open loop, unless you are dyno tuning for drive ability, which you are better off doing on the street.
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Mitsu TD06-20g |3" Downpipe w/ Cutout | 61mm Bored TB |
HP Tuners | Innovate WB02 | Spec Stage 3 | TurboTech Upper | Full Addco Sways | Sportlines & Yellows |
but u dont start the car and pin the throttle on the dyno, startup sux as well as the first drive tryin to get to that magic dyno gear
