No power when engine cold

Hi All,

Recently I've noticed my car seems to have very limited power when the engine is cold. If I'm below 2000-2500RPM and I put my foot to the floor the car just holds speed, I have to drop it a gear or two to actually accelerate, but this only happens in the first 10 minutes ish of driving. The engine sounds like its trying but nothing really happens. Was just wondering if anyone else has come across this/has any tips for what to look into as I've never known anything like this to happen before.

Thanks, Charlie
Only time I had this was when our Micra was in limp mode. This kicked in for us when we had a battery which was aged and the voltage was dropping sufficiently that the supercharger bypass valve was throwing an error, but allowed the car to start. However, this would only reset if we either cleared the code, or simply stopped and restarted the engine rather than resetting mid drive.

What engine and gearbox and year do you have? Any lights on the dash at all?

I probably should've explained a little better. It's a 2011 1.2 no supercharger (hr12de) 5 speed manual. There's no dash lights or error codes on the ecu, and the battery is only 6 months old. I'm starting to think its fuel related as it started when I used BP fuel for the first time and now I've got a tank of shell v power it doesn't seem quite as bad but still worse than it used to be. Are these cars that sensitive to fuel quality? Or could it be anything to do with the new air intake I fitted at roughly the same time? I'm just throwing ideas out as I have no idea what it is

IT could be sods law that you picked up some bad fuel, although doesn't really explain why it runs ok when warm. Run through a few tanks and see if it clears up. If not, revert back to the original airbox.

Did you tie off or disconnect an air lines as part of the intake? If so then this could cause problems as well.

I think the only air line attached to the air intake is the PCV vent, which I fitted a catch can to a few months before fitting the intake and haven't had any problems before now. I'll see how it goes in the coming weeks, thanks for your help