As you can see from my other thread, I'm having issues with my hatch.

https://www.scoobynet.com/general-te...-the-cold.html

However since the last round of repairs I was concious to monitor how the car behaved after the battery was disconnected as when the plugs were changed it seemed to be fine for a week or so and then suddenly start playing up.

I've done 250 miles since the injectors were changed and again, yesterday, the car started playing up after running spot on for the last week.

My question is can the ECU adjust it's map to run badly? I assume that disconnecting the battery for a few hours resets it and then it runs ok. After a while it seems to revert to it's bad old ways and I'm not convinced that my ECU isn't playing up. If there was a genuine problem that the ECU responded to then I'd expect it to go 'bad' straight away, not let it run for a while before running badly.

Hopefully the above makes some sense! I'm now planning on getting it remapped just to try and iron out the issues.

 

Did you get the fuel pump checked or changed?

 

No, that has been mentioned by another member. I was going to uprate the pump at the remap.

Would a failing pump cause issues on one side of the engine but not the other?

 

I am afraid so, if the pressure is low or the pump is breaking down you will not get the right amount of fuel through the lines to the injectors.

Or it may be as simple as the fuel filter not being changed.

I am unfamiliar with the new hatches but my old WRX RA filter when I changed it had a small amount of very fine dust in it but I know it had not been in there long. So depending on the last time yours was changed it may be worth a check.

Take it off and drain it into a glass to see if you have any sh*te in it. If not then it's a simple thing ticked off.

 

Disconnecting the battery won't reset the ecu, it needs to be plugged in and reset via OBD to wipe and reset codes.

 

It's the fuelling map that I was wondering about more than CEL (which isn't lit). I was wondering if the ECU had the ability to alter the fuelling and store that as its default map.

 

It has the power to adjust fuelling to a degree, and if it sees something wrong or out of place within the map it will do what it sees fit to try and keep things happy. If it is repeatedly seeing something wrong then it may not change the fuelling tables back to original map until what ever the cause is solved. It doesn't re write a map as such to use as default tho no, it refers to tables for reference that have been set.

 

OK, cheers for that. I wasn't sure and am beginning to clutch at straws.

Will stick in a new fuel pump and cross that off the list