HELLO
I have just got our car back from the dealer after they replaced the knock sensor. I asked them to reset the ecu to see what difference it would make. The car is a uk std MY98 and had 10k on it when we got it and had always been run on super u/l.After picking it up for the first couple of times i used the turbo i did some heavy left foot braking whilst in both 3rd and 4th gears;the turbo was on full boost for a long time. The result is a much improved `FEEL` in the acceleration dept. The turbo feels much stronger and in general the car is smoother to drive. So if your car is going in for some work , give it a go, what have you got to lose. Just a beneficial experience I thought I`d share with you . comments invited.......

I've been thinking of doing this myself.
Once the ECU has been reset, what exactly do you have to do?

Stef.

Stef,

Join the EMU of course!!

Stef,

Down the pit straight, turn right and then down Craner ... opps I mean the Stef straight !!

Seriously if you disconnect the battery for a while to force the ecu back to its defaults then just drive for 25/30 miles in a mixed (enthusiastic) way and the ecu will start to adapt again. No need to thrash it at all ... in fact thats the last thing you should do.

Bob

I agree with Bob.

I reset my ECU on Sunday (MY97) disconnected battery for just over the hour then went out for an enthusiastic drive with the usual Sunday blue rinse brigade. After a few rather hairy moments http://bbs.scoobynet.co.uk/wink.gif I think that the ECU got the message. The car now pulls much stronger. However, I had previously been using normal UL until quite recently.

As KRIS rightly say's, what have you got to loose!!

Chris http://bbs.scoobynet.co.uk/wink.gif

p.s. Stef, someone did mention on another thread that post '97 cars learn new fueling/ignition/boost parameters quicker.
So there maybe no need to re-set!

Stef - be careful.

If your car is running at optimum settings just now (yours does seem to be a good one) it may well feel slower after the reset.

Scott.

Scottie has a point but if it does then it will recover in time.
However "if it ain't broke" and all that.

Bob

Hmmmm...good point, perhaps I'll wait a little bit longer. http://bbs.scoobynet.co.uk/smile.gif

Stef.

If the car seems to run better after an ECU reset you should ask yourself why the ecu had retarded itself before. This may simply be running the car on lower grade fuel, however if you haven't changed _anything_ before the reset and the car seems quicker after then there is a risk knocking!

If your ecu heard the engine knocking and retarded itself before the reset, clearing its memory will cause it to knock again until the ecu re-retards itself.

As Bob says, you shouldn't really need to put an abnormal load on the engine (left foot braking and so on) after a reset, just drive briskly for a while.

Moray
(Desperately looking for my asbestos suit! http://bbs.scoobynet.co.uk/smile.gif )

hello peeps
Steph, if you have had your car since new then there may be little difference as you would have effectively done the job right from the off. If however you purchased a second hand one with some miles on it you wont know how the previous keeper has driven it. If it has been driven like ` a girly fop` then the parameters will not have been pushed to their limits and the ECU may have got lazy ( for want of a better word). An ECU reset will cure this .Driving in 3rd or 4 th gear with your foot hard on the gas until max boost is achieved and then levelling off your speed with left foot braking allows the turbo to spin up under load and hence increasing those parameters. The same effect can be achieved by driving hard up a steep hill.The ecu then remembers these limits as ` the norm ` and thus the differences.I`d give it a go I didnt drive 25 miles though I think a couple is plenty provided the turbo is boosting......

Ok ... last post about this. (from me)

The act of "booting" the car after forcing the ecu back to defaults will only be part of the ecu learning process, if the car knocks it will pull itself back during this process and so on. Its totally unnecessary and serves no real purpose. Just drive the car in a mixed enthusiastic way as stated.

If the car was good to start ... no difference.

If the car was bad and you change fuel grade ... improvement.

If the car was bad and you stay with same fuel, it feels good to start (and probably knocks) but will very quickly pull itself down ... goes back to where it was.

The ecu has an "adaptive" function and will even improve itself if you just put in SUL after UL with time. The "reset" just speeds up the process. The way you drive the car has no bearing on the state of the ecu.

In any case Stefs ecu should be scared silly after Donnington !!!

Bob

Bob

I know you said its your last e mail on the subject ..but indulge me.. you say the ecu is adaptive. I was told that I must use sul in my 98 uk std 5 dr. If I used normal u/l the ecu would adapt and performance would be lost.IT WOULD NOT THEN RE-ADAPT TO SUL IF I DECIDED TO PUT THAT IN SAY FOR EXAMPLE A TRACK DAY. It would fall back on its defaults and not get better hence sul would be a waste of money.
I will gladly bow to your greater knowledge and wisdom but this info came from subaru mechanic who has nothing to do with my car.

KRIS, dont call him StePH!!!!

Stef, once you reset the ECU, get in the car and drive it son!. I knew you had **** hot brakes but i never knew that they held you up that much http://bbs.scoobynet.co.uk/wink.gif

I notice with my UKMY98 that when it goes in for a service it feels slower when I get it back. After a few miles it starts to boost more and is back upto speed. Quite a strange feeling I am use to taking a car in for a tune up and it automatically feels better when you get it back. I have run SUL from 13 miles on the clock. I was advised by the salesman as it would run smoother. It has been said on here main times that UK spec cars can run on UL but imports especially STiV are SUL only. As far as the ECU reset if the car is running fine and on SUL for a while then you stand the risk of reducing the performance until the car has had chance to learn.

Cheers

chrisp

bump. lol!