As i was wiring up the car for some fog lights i needed to disconnect the battery.........

 

About an hour later i rec-connected it and drove off the pick up the missus when it warmed up i put my foot down and noticed power that wasn't there before,could the ECU somehow have re-set iself?

 

When she drove it she also noticed it was quicker?????

Yes the ECU resets itself after about an hour and will then start learning new settings.

So it would give me more power?

More like restores lost power - The ECU compensates for problems like bad fuel etc. Resetting it restore the default settings.

Ahh could be that i've slowly lost power then got it back!!!

As i was wiring up the car for some fog lights i needed to disconnect the battery.........

 

About an hour later i rec-connected it and drove off the pick up the missus when it warmed up i put my foot down and noticed power that wasn't there before,could the ECU somehow have re-set iself?

 

When she drove it she also noticed it was quicker?????

 

Exactly the same thing happened to me a few weeks ago. Nice suprise eh! :hyper: :hyper: ;)

:cool: If it does feel better all well and good mate, but the ECU will take time and milage to re-learn itself....you would need to drive it for about 40-50 miles befroe it will do this.. ;)

Happy if you have got more.....cos we all know More is all ways better.... :hyper:

So if your car was running on 5 cylinders due to naff electrics would the ecu smell the unburnt fuel via o2 sensors and weaken off that bank? Then when you ve fixed the misfiring would it run too rich for a while till it learned it was running too rich on that bank of cylinders? So how many miles before it re adjusts itself - 5, 10, 50 or 100. I can understand that hard re setting getting you back to the default instantly gets a good result then but I dont see how it can improve things unless it was compensating for a problem before that was then fixed. Otherwise its being stupid with its learning if you see what I mean. Its only going to get back to its old setting eventually unless something had been fixed. Otherwise you need to disconnect your battery every night. Maybe it just feels suddenly different and fools you into believing its better. Running a little rich can improve response but as soon as the ecu senses it it will back it off again for correct emissions etc.

"Maybe it just feels suddenly different and fools you into believing it's better???????"

 

It's a car isn't it?

 

Maybe because you're in Scotland the air is more pure than here in London therefore it runs slightly better because the air is cleaner?

The O2 side of things is always adjusting its settings, its mostly the timing and fuel maps that get adjusted. If the car senses things arnt right at certain ranges, it compensates the timing at that point, this gets remembered. So a bad tank of fuel will have the ECU reduce its performance slightly to make the engine run as well as it can. Reset it and it will assume everything is factory spec and start to learn again.

So if i haven't done it for a while it's always worth disconnecting the battery for an hour????????????

Manual calls it mixture ratio self learning control. Think it only puts a correction which adds or subtracts time on each fuel injector pulse length to richen or weaken as it sees fit. I thought it was only the knock sensor that had the ability to engage safety boost and retard the ignition timing until you re start the engine.

 

The prime objective of mixture ratio self learning is to make the Cats work properly for minimum emissions under steady running, not to give max power.

 

At least I think thats what the manual says - anorak off again.

Its always worth doing every now and then.