over the weekend my mk1 clio started stuttering when accelerating, i can only describe it as driving against super strong winds, sometimes it accelrates fine, others not all, or its stutters and the power delivery isnt constant. I find it isnt as bad if i lift off and accelerate again but after a few seconds it starts happening again. another way to describe it is as if somethings blocked and air cant get through. also happens when parked in neutral, sometimes it will rev up fine and reach top revs and others it will struggle and bounce back and forth between revs while slowly decreasing. any ideas?