Advance Mutiplier resetting on restart?

[xjohnx]

So weird. Perhaps it's time for a google forms survey to gather more data in a sortable format to try and discern a pattern?

[mad_sb]

I have a feeling it will come down to ecu part numbers

[mad_sb]

Originally Posted by AVOturboworld

I've extensively logged, flashed (110 times!), and logged some more on my turbocharged FR-S over the last 20,000 miles of turboboostin', and the IAM has never reset itself. None of the cars I've seen or flashed personally has reset either, FR-S or BRZ.

It always resets to the initial value set in the rom on a reflash, i assume your talking about post flash.

[AVOturboworld]

Yes, in reference to the first post.

[Toma]

Stock tune, the multiplier always goes to 0.7 after a key cycle.

This is how some of the "before and after flash" dyno sessions looked so "good", new tunes often have the multiplier set to one on start, and you have to knock to see it reduced.

[Wepeel]

Maybe this is something that is dependent on the ECU Calibration? 00C vs. 01C? If anyone knows the IAM PID info then anyone with Torque should be able to check...

[mad_sb]

Originally Posted by Wepeel

Maybe this is something that is dependent on the ECU Calibration? 00C vs. 01C? If anyone knows the IAM PID info then anyone with Torque should be able to check...

Rom version has already been ruled out. Reading the IAM value requires direct ram access, i do not believe torque can do that.

[mad_sb]

Originally Posted by Toma

Stock tune, the multiplier always goes to 0.7 after a key cycle.

This is how some of the "before and after flash" dyno sessions looked so "good", new tunes often have the multiplier set to one on start, and you have to knock to see it reduced.

Which vehicles?

We already have a number of folks that the IAM does not reset after a drive cycle. So far it seems mostly subarus that the IAM persists on but we do have a few toyota / scions that seem to persist as well.

[Toma]

Originally Posted by mad_sb

Which vehicles?

We already have a number of folks that the IAM does not reset after a drive cycle. So far it seems mostly subarus that the IAM persists on but we do have a few toyota / scions that seem to persist as well.

Every FRS I have had on the dyno starts at 0.7 on start up (no flash). I hold the pedal wot against the dyno brake at about 2000 rpm for 15 or 20 seconds, watch the multiplier climb to 1, then I release the brake and make the pull. I have only had Scions on the dyno though, can't comment on BRZ.

I use Epifan to log, and it's no software glitch, cause if I make the pull before the multiplier gets to 1, power is significantly down, as is logged timing.

I think we even made a video demonstrating this to dispel the myth of giant gains with a tune..... I'll dig it up, or do it again. Also, we are in Canada, if that makes a difference.

[FA20Club.com]

stock ROMs its set @.7

[mad_sb]

Originally Posted by Toma

Every FRS I have had on the dyno starts at 0.7 on start up (no flash). I hold the pedal wot against the dyno brake at about 2000 rpm for 15 or 20 seconds, watch the multiplier climb to 1, then I release the brake and make the pull. I have only had Scions on the dyno though, can't comment on BRZ.

I use Epifan to log, and it's no software glitch, cause if I make the pull before the multiplier gets to 1, power is significantly down, as is logged timing.

I think we even made a video demonstrating this to dispel the myth of giant gains with a tune..... I'll dig it up, or do it again. Also, we are in Canada, if that makes a difference.

Right, and this jives with what i see as well. It does not matter if it is a stock rom or a tuned rom, after the engine cranks the multiplier resets to the initial value in the rom that is in use. I have seen it keep the learned IAM between drives when the off time is short, like when you out running errands and the car is parked for a few minutes at a time. But once it sits long enough, over night for sure (and probably just long enough for the coolant temp to drop lower than some threshold value) it resets to the initial value on the next start up.

It does seem to happen during the cranking cycle. I believe if you connect the logger and check the IAM and fine learning table at key on, the learned value will be there, but the instant you crank the car, it resets.

So far it seems to be the push button BRZ's and handfull of scions that keep the learned IAM across drive cycles.

[ft_sjo]

Why don't you check the switched power to the ECU? I know for a fact it keeps the fuel injectors live for quite a while after you key off. Could be related.

[King Tut]

Originally Posted by mad_sb

So far it seems to be the push button BRZ's and handfull of scions that keep the learned IAM across drive cycles.

Not just the push start BRZs. Bob @Circuit Motorsports said he tuned a BRZ Premium that had persistant IAM. I think it has to be a wiring or ECU change. Perhaps Make, Model, and Production month and year would be a good start to collecting data.

[mad_sb]

Originally Posted by ft_sjo

Why don't you check the switched power to the ECU? I know for a fact it keeps the fuel injectors live for quite a while after you key off. Could be related.

I thought about that but it is not a power issue. If you key on but don't start the engine the IAM and fine learning will still be there from the previous drive cycle. Once you start the car, it resets to the roms initial IAM value.

I will double check this afternoon when i leave the office.
EDIT: confirmed after sitting for 6 hours or so, keyed on, connected logger, refreshed learning view... same values were there from before I shut off the car at work this AM. Left logger connected, started engine, refreshed learning view, fine learning was reset to all zero's. I am back on E85 now and have initial iam set to 1 in the rom so there was no change to notice in the IAM but since fine learning was present prior to cranking i'm 100% sure this has nothing to do with power connections to the ecu.

Originally Posted by King Tut

Not just the push start BRZs. Bob @Circuit Motorsports said he tuned a BRZ Premium that had persistant IAM. I think it has to be a wiring or ECU change. Perhaps Make, Model, and Production month and year would be a good start to collecting data.

Yup, most of us already posted that a couple pages ago..