RPM jump up and down, cold start issue?
Got a Mclaren today, 2013, full service done by Mclaren 100 miles ago. When I cold start my RPM jumps 500-1k up and down up and down shuddering almost as if its starving for fuel. No lights, and Mclaren says everything checked and and nothing should be weird, they said maybe an oil cap or something small. Anyone else experience this! Please help tried to get a video and can't, it wont do it again until its fully ice cold the engine. If I rev it the rpm levels off and it stops doing the quick up down up down RPM revs on its own.