I went away for a week ,and rather than have to face a flat battery due to the poxyTracker on my 05 STI(ppp)on my return, I disconnected the battery for the time I was away. Now it may just be my imagination but the car seems to be really flying now , pulls so much stronger .Have I caused some kind of ECU reset(I seem to remember this was possible on classics), or am I just going bonkers ?

Dave

 

yup disconnected for that long it will have reset

 

when you disconnect the batery it resets the ecu. you then get max possible ignition advance and the car runs better until the ecu detects knock and then the ecu retards the ignition and performace is lost. the problem is the car will easily retard igtion but it does not advance it as easily and therefore a ecu reset cheats this.

 

IIRC I was told that ideally you go out fully loaded and find a hill, then run up through third gear at wot, and the ecu will push the ignition timing as far as possible (safely !).

I also found that after a month of crawling to work, mine started (trying !) to be economical, and felt flat and farty.

HTH

dunx

 

I think after a reset, the ECU starts off at the 'middle' coarse IAM position of 8 (range 0 to 16) - then it advances (hopefully wont retard! lol) as much as is safely possible after varied loads placed upon the motor... Which is why it's good to do what dunx says, to get to max ign. adv. ASAP ( although IIRC from what Scott T told me, it'll get there after about 20mins of varied driving anyhow...).

 

Apparently if you reset ecu, then take her out to motorway find third gear, hold foot on brakr and push down on accelerator building up boost pressure works. Same general idea as the going up hill with full load on accelerator

 

The fabled 'fast learning trick' :-

Scoobypedia | Trusted knowledge for everything Subaru | Knowledge / ECU Fast Learning Trick


Article also tells the OP how the ECU learns ign.adv/ret.

 

Thanks for the relpies all , very interesting

 

after it advances,making car more powerful! is there a way to stop it retarding

 

how can you go about doing this with a '95 auto wrx???? left foot braking whilst holding the accelerator? what are the benefits from an ecu reset?

 

It'll automatically stay at the optimum ign. adv. anyway i.e. as much as is safe for the engine..... UNTIL/UNLESS it sees detonation. In which case it puts its comforting arm around you and retards the ign. timing, thus potentially saving your engine from an expensive 'blow-up'!

Believe me - you WANT it to retain its retardation feature!

 

It'll clear 'forever' any erroneous fault codes.

It'll lose any possible 'badly' learnt settings, allowing it to start again from scratch. Thus optimising the ign. timing, fueling, etc. for your chosen fuel, etc.

 

So is it best to go out and stick half a tank of shell v power in first before you disconnect the battery? How long do you really need to leave the battery off for?

 

I did mine for three or four hours yesterday while at work (left it in my workshop as no alarm !!!)

 

Just use V power all the time and chances are the car won't ever have to pull the ignition, unless you get a contaminated batch!

Ns04

 

By disconnecting battery does this reset it better than plugging the black & green clips together ?

 

Doing it by the connectors is the 'proper' way.


Yes, run the tank down and put in V-Power BEFORE you do the reset (and keep using it all the time, if poss). As when it's reset, and when you start driving, it'll immediately see 99 RON and you'll have optimal ign. timing after a period of varied loads on the engine have been applied. Hopefully it'll adv. to max (everything being okay.)

If you do reset via the battery, disconnect for at least 30mins. What I'd do is stick in V-Power late at night and disconnect batt. overnight, etc... lol

 

does the early classics/wrx's ECU's advance/retard ignition timing as well or is it just the newages , just always wondered why the car felt a bit slower after resetting the ecu lol

 

Yes, all of the OEM JECS ECUs have IAM (ignition advance multiplier) feature, which has the ability to equally advance, or retard, from the reset's "middle" position.

So yes, when you did the reest, you would have retarded the ign timing back to your MY ECU's "middle 8" [sing it, lol] position - hence it feeling slower. Because before the reset, you would have invariably had most of, if not all, of the advance - up to the max of "16" (dependent on knock activity - if any.)

Don't worry though, it'll be fully optimised again within a few varying loads on the engine...

 

Will my insurance company be able to tell I have had a 'Reamp' and will it affect my warranty ?

 

what your doing is clearing the kam memory. and dont forget about open and closed loop, full throttle uses the values from the chip, the ecu can only fine tune the map not remap it.
adam

 

With a newage ECU just disconnecting the battery for a bit won't reset the ECU. You need to perform a reset via a laptop or diagnostic device plugged into the EOBD port. Perhaps if you leave the battery off for long enough then it may well reset but generally speaking it has to be done electronically.

On classic scoobs leaving the battery off for a bit works as is well documented.

Best way to relearn values (this is what i do with my own and customers cars) after a reset is drive your car for a couple of mins then pull over and switch the ignition off for 30secs. Restart and go for another drive for another few mins, pull over and do the same again. Then restart the car, find a straight bit of unpopulated road and hold 3rd gear for 30secs at around 3500rpm, then build up the revs/engine load progressively and it should very quickly get to an IAM (Ignition Advance Multiplier) of 16 (16-bit ECU's) or 1 (32-bit ECU's - MY06+). You don't need to load your car up with gear to get there, just follow the process and it will work.

Unfortunately unless you have a laptop or diag device plugged in you can only tell if you're up at full IAM by feeling it.

Good luck

 

This is great stuff.

MY99 has seemed to loose something power wise. I'm taking it that the non mapped K+N will cause the ECU to retard thus the power loss. My car still pop's on overrun or coasting down hills (Lean?) so after fitting a standard airbox would this reset work for me?

 

Popping and banging on overun means it's either still throwing fuel down the cylinders (like an Anti-Lag system) because the injectors aren't switching off on overrun, or more likely it's running lean. A proper loud backfire however would mean it's leaned right out, not good.

Adding a K&N to a non remapped scoob will in effect lean it out. If you then remap for the K&N but later on change back to the std OEM airbox and filter it will run rich.

A proper remap will cure any popping and banging, and if your EcuTek dealer asks you if you want pops and bangs on overrun as part of your remap just say no, it's just so crap.

Edited to add: If your car wasn't remapped for the K&N then fitting the standard airbox and a std air filter should sort that as your MAF is scaled for the standard setup. Fitting a high flow flat panel air filter in the airbox may still give you the pops and bangs so K&N or high flow flat panel either way a remap is the way forward.

 

I won't be having a re-map for a while due to fund's. When I fit the standard airbox would a reset be a cheap fix/work?

 

Will be fine mate, reset wont hurt either. Unless you have evidence I would assume it's not been mapped and therefore expecting the airbox anyway.

 

The K+N was on when I bought it and I don't think the previous owner was very clued up as to the con's of fitting it. No re-map proof so the standard airbox will be going back on (now I have found one). Along with the re-set I am hoping for some good results.