Stock Ecu Learning Mode.

[Andyn]

I've got an avcr boost controller and recently reset the ecu then I drove the car for 45mins on 0.65bar boost. No probs there.

Then today I cranked it to 0.75bar, for the first time after the reset, and i couldn't believe my eyes on the amount of petrol it chewed. I was driving casually for about 25km occasionally giving it a kick in the guts and it went through about 10-12L!(It was exactly on the 1/4 full line on the odo when i started, and it was almost empty after the drive). It didn't feel responsive at all either. I'm not worried yet, as im assuming the ecu is trying to sort itself out.

I'm guessing the ecu is trying to get the ratios right, so after a few more trips on 0.75bar it should sort itself out and get back to normal. (touch wood) Can anyone correct me or shed some light on what they think might be happening.

Also can anyone confirm that when u reset the ecu, and u have an elect boost controller, that u have to drive the car on each setting to make it relearn properly. Or is keeping it on one boost level sufficient (and just vary the revs).

Hopefully this thread is useful for others in the same situation, or just curious.

[justin911]

i have reset my ecu a few times after doing a few mods here and there, and i could never tell the differance after reseting it...

oh yeah .75 bar is like 10-11psi ya ? maybe your ecu is going into rich / retard mode because theres to much boost.. try lowering the boost to like 9psi and see what happens

[rob82]

I've got an avcr boost controller and recently reset the ecu then I drove the car for 45mins on 0.65bar boost. No probs there.

Then today I cranked it to 0.75bar, for the first time after the reset, and i couldn't believe my eyes on the amount of petrol it chewed. I was driving casually for about 25km occasionally giving it a kick in the guts and it went through about 10-12L!(It was exactly on the 1/4 full line on the odo when i started, and it was almost empty after the drive). It didn't feel responsive at all either. I'm not worried yet, as im assuming the ecu is trying to sort itself out.

I'm guessing the ecu is trying to get the ratios right, so after a few more trips on 0.75bar it should sort itself out and get back to normal. (touch wood) Can anyone correct me or shed some light on what they think might be happening.

Also can anyone confirm that when u reset the ecu, and u have an elect boost controller, that u have to drive the car on each setting to make it relearn properly. Or is keeping it on one boost level sufficient (and just vary the revs).

Hopefully this thread is useful for others in the same situation, or just curious.

Week after week I see another thread about ECU resetting and the misunderstanding of what it actually does and the problems it can cure.

It may not fix a shitty idle if:

1. the plugs are f**ked

2. the base timing is wrong

3. there is a manifold leak or PCV valve or rocker cover vent is venting to atmoshere

4. the MAF or another sensor has failed and or wiring to the sensor/s

5. TPS sensor is not zeroed with throttle closed

It will not fix open loop fuel mixtures, that means resetting the ecu will only affect closed loop fuel control which is "approximately" between 0 - 4000 rpm and from vacumm to about a couple of pound of boost (very general description). So above 4000 rpm and above around 2pound of boost the mixtures will go rich as this is standard nissan programming.

Resetting the ECU may increase timing as there is usually two ignition maps hi and lo but this is usually only if the ECU has seen enough detonation to warrant defulting back to a low octane map.

Resetting the ECU does a few other things with idle stability usually leared cranking IAC position or learned idle IAC postion but I wont go on.

The most likely problem with excessive fuel consuption is the fact that you've increase the boost to a point in which the car makes no more power as the ignition is that far retarded and the AFR's are so rich. Hope this clears up some misconceptions.

[Andyn]

I've just got info from the archive of past threads and I was curious so I thought the only way to learn is to try it urself. I'm keen to have a chat with someone who knows what actually happens apart from hearing comments like "IT has made my car run better".

The thing is that I was running 0.75boost fine before I reset the ecu, and fuel consumption was fine. So just wondering after the ecu was reset, why the fuel cons is playing silly buggers and car feels less responsive only on higher boost setting? what could have been changed... ?

Comments most welcome.

Edited April 6, 2006 by Andyn