Lancer Register Forum banner
1 - 9 of 9 Posts

Discussion Starter · #1 ·
After carefully running my evo 6 tme in, and sticking to the 4000 rpm barrier i was wondering about re-setting the ecu. Is this possible or is it a load of rubbish? Some of the Subaru people talk about this as a compulsary mod. as the ecu can learn your driving style and adjust it`s setting`s accordingly ie- lower boost levels. If you reset the ecu, you go back to factory settings so after pootling round for 1000 miles in the Evo, would it have learned the low boost characteristics of this driving style, or, am i thinkihg and talking rubbish? If i am correct, is it a case of disconnecting the battery for a certain length of time?
Regards. SIMON.

Discussion Starter · #2 ·
Resetting the ecu is quite simple disconnect the battery for 10-20 secs .reconnect and leave the car running on Iddle for at least 5 mins,this apparently sets thing back to standard.
Then take it for a drive.hope this helps

Discussion Starter · #3 ·
I had to disconnect my battery the other day to replace it. The car is running a Ralliart sports ECU and peaks at 1.5 bar on the boost gauge. Do I have to get the ECU reset due to disconnecting the battey or will it stay on the previous setting.


Discussion Starter · #5 ·
This thread is a pi55 take shoooorly ????????

ROFL ROFL ROFL !!!!!!!!!!!!!!!!!!!!!!


Discussion Starter · #6 ·
Yellow 5.

No this is not a #### take. Some of us EVO owners love the car
but have no idea on what can go wrong if you start playing. I leave
all the technical stuff down to the my local garage. I am too busy
to spend all day on the computor and read technical manuals to
prove I am the most knowledgeable.

Why dont you take a leaf out of Heave Ho Six's book who is always more
than willng to help us none technical EVO owners.

I thought this was a site for everyone not just for the Tefal Heads.

We all start somewhere.


Discussion Starter · #7 ·
The ecu basically has a long term fuel and ignition trim adjustment.

This is mainly for correcting for shitty petrol or problems with the engine. If you lose low octane the ecu will back off the timing (and hold the boost solenoid shut more?) and you will notice the slight lack of power. Even after using high grade petrol again the ecu will take time to push the trim values back to zero. Disconnecting the battery will reset these values back to zero.

Worth doing if you notice things are a tiny bit sluggish and you have a fresh tankful of Shell Optimax for the track day instead of that cheap crap you sometimes fill up with when your feeling tight. Also useful if you have effed up the restrictor sizes whilst 'home tuning' and overboosted everything - then got it back to standard boost.

Discussion Starter · #9 ·
Yep, lightspeed is pretty much bang on.

There is still a fair bit of confusion when it comes to re-setting the ECU
and why it needs doing.

Take a Jap spec Impreza for an example.

This car(like ours) is mapped for Jap 100-102 Ron fuel; use one over hear on our carrot
juice 97 Ron fuel you'll get detonation; the ECU uses a crude device to
try and stop detonation which is called the knock sensor. When this
sensor picks up det, the ECU reacts by retarding the ignition advance
a little and it keeps doing this until the det stops. I have heard there
is a problem with some models of impreza where the ECU cannot
retard the ignition enough to stop detonation. This could explain
why so many impreza engines are melting pistons 8-(

When the ignition is retarded, you lose power and fuel economy.
Which is why octane booster is selling so well.

Now, with the scoob, once the ignition has been retarded , even
if you fill with 102 ron fuel , your ignition will not advance back to the
original map to get the benefit from this fuel without being reset.

It is rumoured, to reset the ECU on a scoob you need to take the
car back to a main dealer. Not too sure if this is true or not,
but disconnecting the battery for 5 minutes wont do it.

I have been advised by an ecu mapping expert, that this is not the
case with evo's . The ECU has the ability to advance/retard ignition
to suit the RON of the fuel VERY quickly; infact, I was told,
it reacts so quickly you dont even need to reset the ECU.

If you really did want to reset your ECU, just to make sure,
I would leave the battery disconnected for as long as possible (a couple of
days!); with the supras all you have to do is remove the EFI fuses,
turn the ignition on for a few seconds and bingo....reset.

1 - 9 of 9 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.