Unstable Revs After Battery Change.

[fireblade2322]

I changed my battery a couple of days ago and I noticed the revs have become unstable since then. When I'm driving on the freeway and let go of the accelerator the revs drop to around 1k and when I start pressing on the accelerator pedal again there's a 1 or 2 second lag before you can feel the car picking up speed, the car starts picking up speed again at around 3-4k.

I don't know if this has anything to do with the fact that I changed my battery but it definitely started happening after the battery change, could this have something to do with the ECU being reset during the battery change?

[Moodles2]

Clean up the battery terminals, and clean up the chassis ground. Bad batch of fuel, boost leak, faulty/dirty AFM can cause what you describe.

The ECU will have been reset, but that's mostly autolearning things.. but it shouldn't cause what you describe.

[fireblade2322]

Clean up the battery terminals, and clean up the chassis ground. Bad batch of fuel, boost leak, faulty/dirty AFM can cause what you describe.

The ECU will have been reset, but that's mostly autolearning things.. but it shouldn't cause what you describe.

Thanks, I had a look under the bonnet and something didn't look right to me, I don't have a photo of it but I found an existing photo to try and illustrate what I saw.

There's a manual bleed valve / boost controller with 2 hoses connecting to either side but nothing connecting to the bottom, Is that how it's supposed to be or does the hose that's capped off need to be connected to the bottom of the bleed valve? The bottom of the bleed valve looked like some black oil was leaking out of it as well.

[Moodles2]

The 3rd port is used to bleed air on an internal wastegate setup, it's only ever connected with a external wastegate. As for the oil you probably have some blowby oil in your intake pipiing.