Tiny 2V light bulb... £150
 

I took my dash clocks out to fit a blown light bulb for my clock.

The clock works now, but the car drives like poo... have I accidentally reset my ECU by removing the dash clocks?

I've got a '99 STi with Simtek. I probably should have disconected the battery before removing the clocks am I right?

Did that little 2V bulb just cost me a remap?? :(

It wouldnt wipe ur map anyway but did u disconnect the battery? If so that can reset ur ecu not wipe it clean,
Are you sure u havent blown a fuse while fiddling? still not sure why it would make your car run poor but worth a look as you have been playing with the electrics.

No reason why you would need to remove the battery just to take the instrument pack out. Disconnecting it doesn't affect or remove the power supply from the ECU in any way, and even if it did, as Stig says the mapping is stored in non-volatile memory so it won't matter anyway.

On the face of it, unless your car has some sort of electrical fault, there's no obvious reason why what you've done should cause any change in behaviour or performance.

Might be easier for us to work out what's going on if we knew what "drives like poo" means.

I didnt disconect the battery... all I did was unplug and remove the dash clocks to change the bulb and after replacing the dash clocks it now drives like poo.

Poo meaning, when I put my foot down its like it hits a wall and doesnt want to boost anymore. It was driving fine b4 and now there's what seems like a boost problem?

sounds like it could be in limp mode but ur description isnt great is it?
What revs does it bog down ? 4500 rpm? every gear, does it boost at all?

It rev's fine, but when engaged in gear it hits about 4k and bogs down...

I only drove it last nite very briefly after swapping the dash clocks so cant give more of a description rite now. Will have a more thorough checking over later on this eve.

Ok just tested it and it goes thru the gears fine until 4-4500rpm when its as if its hitting a limiter...

...my anti lag has launch control set at 4-4500rpm could this be sumin to do with it or just a coincidence?

When I linked the dash clocks back up it did make the alarm go off which might indicate ECU activity?

Is the speedo working okay ?

you have got it switched to the correct map havent you? dont know if your using a seperate switch or the rev counter to switch maps?

very good point, if the speedo isnt working it will go into limp mode also

Im not so sure the simtek ecu even has limp mode

I've got 2 maps, set thru the rev counter... but I've checked them both and the problem is there regardless.

Ok my next test will be take the speedo out and drive the car and see what happens. Hopefully give that a try 2moro...

Update:

I've removed and replaced the speedo so many times now and even tried driving without the speedo... no change, the speedo works fine.

However if I boost gentle it goes right thru the rev range no problem, but if I put my foot down around the 4k mark it hits a wall.

That to me sounds like a vacuum problem, but it was working fine b4 the speedo came out and like this immediately after?

Could I have disconected the speedo converter (kmph to mph) when I yanked the loom behind the speedo? Would this cause this type of problem? A couple of ppl have suggested this could be the cause.

I've been behind the speedo and under the driver foot well, but to be honest I dont know what I'm looking for. What does that speedo converter look like?

I know its going to be such a silly little problem thats causing all this agro...

Sounds like you have disturbed the speedo signal to the ECU and it's going into launch control mode.

Thats the 1st thing I thought of and hats what the mapper thought might be the problem and I cut the launch control wire... still doing it.

I just had another word with the mapper and he said sounds like overboosting and that does fit the symptoms.

Gonna let the ECU doctor work his magic - weird it happened just from unplugging the dash clocks