On way home from a 30 mile highway trip, MINI stumbled while climbing a hill at about 45 MPH in 4th gear. it then regained power. No codes according to Actron, no CEL. Tried again, same thing occurred and still no codes or CEL. Any ideas where to look for the problem? It's a 2009 JCW, 6-speed manual, 78K miles. Replaced plugs and #2 coil pack following #2 misfire last week.

I really appreciate any help you can give.

 

Maybe HPFP starting to go out? How is it idling after bone cold start? I'd replace the other 3 coils first, way cheaper than fuel pump.

 

Might want to replace the fuel filter?