Kary,<P>Be careful! Sounds like you lead a DANGEROUS life!<P>You're right, it's probably "ping" or detonation, it sounds sharper than the usual valve chatter. I'm usually running mid-grade fuels, usually Shell, or Chevron. The problem startd on Shell, and continues through a second tank of Chevron.<P>I'll put the timing control on the list, though it will tke a few days to get there. Last welding class tomorrow, so been busy getting ready...<P>Thanks,<P>Don

Don `87 Mitsu 2dr, Rubicon survivor, GModified.