Edit And Self Learning Pcm

[aaronmihe]

If the Edit is done right self learning is going to happen around the new "target" points for the ECU.

Ofcourse this doesn't mean they won't tune "down" a bit based on some things. Example I can think of immediately is knock sensing. the ECU will downtune itsefl away from the knocking/pinging, but rarely do they pick themselves back up again to the same level that the knock/ping occured.

Resetting this memory space (disconnect battery, reflash etc) shoudl let the engine operate closer to the maxmium performance.

I recall that even in the early '90s a lot of cars were logging stuff for the last 50 ignition/engine run cycles. For a car driven to and from work that's 25 days, and somethign that happened at some point in that 25 days could lead to the car detuning until the cause didn't recur for 50 cycles...

A.

[Adam]

When the car is being tuned with edit they tuner turns the adaptive learning off (Nizpro does anyway) this makes sure that after each adjustment all the other settings stay the same. Once tuning is complete it's turned back on. If your wondering about it put your car on a dyno that can log OBDII data and then with the car idling watch the fuel trim values get adjusted.

[jordak]

When the car is being tuned with edit they tuner turns the adaptive learning off (Nizpro does anyway) this makes sure that after each adjustment all the other settings stay the same. Once tuning is complete it's turned back on. If your wondering about it put your car on a dyno that can log OBDII data and then with the car idling watch the fuel trim values get adjusted.

<{POST_SNAPBACK}>

So it is possible that following the custom tune and the adaptive learning being switched back, on the ECU could play around with the tune given certain conditions!

[Adam]

That's right.

I wouldn't say in "certain conditions" though, the PCM is always adapting itself.

I've got my adaptive learning turned on and everything is just like the first day it was tuned.

[jordak]

That's right.

I wouldn't say in "certain conditions" though, the PCM is always adapting itself. 

I've got my adaptive learning turned on and everything is just like the first day it was tuned.

<{POST_SNAPBACK}>

Are you running a piggy back or edit?

And when you say that everything is just the same as the day you had it tuned are you going by seat of the pants or have you had the car on the dyno again since the tune?

[Adam]

Edit mate.

Just by the way it runs and the times I've run on the quarter mile. It would be common sense to get the tune checked every 12 months or so though in my opinion.

[macka'sxr6t]

Edit mate.

Just by the way it runs and the times I've run on the quarter mile. It would be common sense to get the tune checked every 12 months or so though in my opinion.

<{POST_SNAPBACK}>

Thanks for the feedback Adam

I would have thought about every 12 months would be good time. That's why I asked the question. Some people would have had their edit tunes for 9 months now. It will be interesting to see if they have changed at all if and when they get them checked.

macka

[jordak]

Edit mate.

Just by the way it runs and the times I've run on the quarter mile. It would be common sense to get the tune checked every 12 months or so though in my opinion.

<{POST_SNAPBACK}>

Thanks for the feedback Adam

I would have thought about every 12 months would be good time. That's why I asked the question. Some people would have had their edit tunes for 9 months now. It will be interesting to see if they have changed at all if and when they get them checked.

macka

<{POST_SNAPBACK}>

Apart from mine I know of at least one other forum member whose tune had changed with respect to a drop in power and AFR's and this occured over about a 2 month period.

At the time one theory was that if you go a while without given it a bootful the ECU makes adjustment for the more sedate driving style.

[macka'sxr6t]

Hi Jordak,

Interesting couple of posts you've made. So I gather you noticed something was not quite right and then had it checked on a dyno.

Do you know how much your tune had been altered. eg timing etc.

Would it be better to have the self learning disabled if you have a custom tune done?

What dis-advantages if any would this cause?

macka

[jordak]

Hi Jordak,

Interesting couple of posts you've made.  So I gather you noticed something was not quite right and then had it checked on a dyno. 

Do you know how much your tune had been altered. eg timing etc.

Would it be better to have the self learning disabled if you have a custom tune done?

What dis-advantages if any would this cause?

macka

<{POST_SNAPBACK}>

Hi Macka

Have'nt had the chance to check the tune parametres as yet so don't know about timing etc but the dyno confirmed that we had lost some boost across the rev range resulting in the drop in power mentiioned earlier.

From what I can understanding disabling the self learning will remove the "safety net" (knock sensors etc. ) which probably isn't a good idea.

Perhaps Street Tuna or others could chip in with their thoughts