Knock and Ping

[tcossey33]

OK so i decided the strange sound coming from my engine is predetonation and that i need to adjust my timing ......do i need to advance it or retard it a couple degrees?
Its and 87 gw
thanx

[89grand]

If you're timing is set correctly try using 92 octane premium. That's what I had to do to eleminate my mild ping problem. I that doesn't work than you may want to retard the timing a few degrees.

[Don S]

..
tcossey33 ...
... Retarding the timing may help reduce ‘pinging’ but carbon deposits in the combustion areas can glow and cause pre-ignition and dieseling or ‘run-on.
... Using ‘high test’ every so often is a very good idea and should not need retuning of the engine for one or two tank fulls.
... Part of the increased price of the high test in most brands is cleaners that they don’t put in regular gasoline. Crudy fuel injectors on modern cars will usually be cleaned and run much better with a dose of high test.

... The idea described in the link below has worked wonders for me over the years. If you have short runs with a cold engine it may take a little longer to work.
... It doesn’t cost much…

FUEL TANK ADDITIVES
http://groups.msn.com/ATexasOklahomaJeepClub/ouraycotopic.msnw
AND
http://www.ifsja.org/ubb/ultimatebb.php?ubb=get_topic;f=2;t=010756

Good Luck ;) and CUL.. Don S..