I put on the Steeda Firewall adjuster and got it to the place I like it to engage at. The pedal vibrates when driving and on startup, and I have still not figured out this problem. At 68k I wouldn't think the clutch cable itself would need to be changed? My friend said that the cable itself seemed loose and that it should be tighter. Could a loose cable be causing the clutch pedal to vibrate? If so how can I tighten it?