I've got a 2001 S3 with the AMK engine. About 2 weeks ago I removed the fuel injectors and sent them away to be cleaned and flow tested. I also changed the spark plugs at the same time and took the inlet manifold off to clean it up and spray it black.
I hoped that doing the injectors and plugs would improve my MPG which had been sitting at 24-25mpg on the DIS but since re-fitting everything I'm only getting 22! I've covered about 250 miles since and it's not improving, I if I give it some beans it drops even further. Is this normal and will it improve once I cover some more miles? Even when I've disconnected the battery in the past I've never had an average MPG that low after a couple of hundred miles.
The car is fine to drive and there's no apparent loss of power. No improvement in power either unfortunately but the report that came back with the injectors only showed a 2 to 4% improvement in flow rate per injector so I wasn't expecting much.
I've re-checked everything that I'd messed around with, I can't find any vacuum or fuel leaks and all the electrical connections look good. I've scanned the car for fault codes after every drive but there are none stored in the ECU. I did get an error code of 18010 to do with low voltage when I first started it but I understand that's normal when the battery has been disconnected for a while, I cleared it and it hasn't come back.
Should I just wait and see whether the MPG gets better over time or is there anything else I can check?
Any ideas would be appreciated.