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View Full Version : Rough Idle After EFILive Flash



samh_08
October 29th, 2013, 03:56 PM
I simply read the stock tune from a 2011 Silverado E38, added 10% to the 'Torque Model' tables and flashed the tune into the ECM after licensing it.

My question is, being we dont necessarily have access to every table in this ECM, do we lose anything by flashing an EFILive tune over a stock cal?

I noticed it right away when I started so I let it be cause I had to drive 100 miles anyways today, but it was still idling much rougher after the trip.


Ideas, info?
Thanks!

joecar
October 29th, 2013, 10:15 PM
Re-flash the tune and see what it does.

samh_08
October 30th, 2013, 04:57 AM
Today it has been good, completely different than yesterday. I'll leave it be for now but Im still curious about my question above..

Chevy366
October 30th, 2013, 08:05 AM
I simply read the stock tune from a 2011 Silverado E38, added 10% to the 'Torque Model' tables and flashed the tune into the ECM after licensing it.

My question is, being we dont necessarily have access to every table in this ECM, do we lose anything by flashing an EFILive tune over a stock cal?

I noticed it right away when I started so I let it be cause I had to drive 100 miles anyways today, but it was still idling much rougher after the trip.


Ideas, info?
Thanks!

Something that I have noticed and complained about a few times, it seems as if EFILive does something to the EPROM that clears more than it use to. When I say "use to" I mean from several years back, you could flash a tune and see no real difference in idle, or idle would respond quicker and idle normally, now it seems that the idle has to relearn more parameters and will run rough for several drive cycles before it calms down and idles correctly, at least that has been my experience lately. The more you let it idle the faster it relearns idle it seems. SRT can show ready and it will still idle rough, I thought maybe it was O2 sensors not ready but not the case.
I have logged data before but did not see anything that just stood out. I know mine will throw a P0300 code every time I reflash on first idle, I clear that and it will not reappear but will still idle rough for days or several drive cycles.

No help I know, but at least you are not alone.

macca_779
October 31st, 2013, 01:48 AM
But if the idle settings are good any learning will be negligible.

samh_08
October 31st, 2013, 02:43 AM
But if the idle settings are good any learning will be negligible.
So a completely stock pickup's idle settings aren't too close?

Wheelz
October 31st, 2013, 03:19 AM
So a completely stock pickup's idle settings aren't too close?

I full flashed an E38 and stock idle was spot on... LS1B is another story, but I've been able to modify the settings so mine is spot on after a full flash. I wonder if this is related to an incorrectly calibrated MAF (cal changing with age and cleanliness)

Chevy366
October 31st, 2013, 05:59 AM
So a completely stock pickup's idle settings aren't too close?
I doubt that seriously, don't you?

I full flashed an E38 and stock idle was spot on... LS1B is another story, but I've been able to modify the settings so mine is spot on after a full flash. I wonder if this is related to an incorrectly calibrated MAF (cal changing with age and cleanliness)
Does the same thing with a Speed Density tune, no MAF? Have completely built a new tune from scratch, same thing and by Script method, same thing.

samh_08
October 31st, 2013, 06:47 AM
I doubt that seriously, don't you?
To be honest, I've only tuned modified vehicles so I guess I just assumed factory was very close. Apparently not the case?

On a side note, should I be doing a 'full flash' the first time I flash an EFILive tune coming from stock?

Wheelz
October 31st, 2013, 10:52 AM
I doubt that seriously, don't you?

Does the same thing with a Speed Density tune, no MAF? Have completely built a new tune from scratch, same thing and by Script method, same thing.

I would recommend adding air in 5-10% increments to B1829 for revs below 800, and maybe adjust B1832 as well if it's struggling to start without throttle input. If it struggles when the A/C starts try adding air to B1825 and B1826. Just small percentage amounts and see how much it changes. Those tables should have similar effects to the ones I changed on my LS1B to make it idle correctly after a full flash

It took me all day to get my LS1B to idle right when I went speed density, but I didn't let I learn. I trial and error added airflow till it would idle on its own, and my idle desired airflow values (B4307 in my tune) are almost double what they were from factory (but I also elevated idle speeds slightly).

Also I've noticed the VE table's correctness influences idle quite a bit in SD. If you change your VE values it using to idle, expect your idle to have to relearn or manually tweak the values.