Have a stock 89 2.0 5-speed low miles in outstanding condition. Engine runs very good except it really pings (preignition) at multiple throttle positions when hot. 93 octane gas helps a little. Ethanol free versus E10 gas makes no difference (E10 caused enleanment might worsen detonation). Timing is to spec and Autolite plugs are what the manual calls for (plugs look good - not like its running excessively hot). Engine appears to be running normal temp (needles always "in the middle" of the gauge). Any ideas? Its been a long time since I've tinkered with one of these "final days" of carbed smog engines, remembering sometimes the poorly controlled red-hot EGR gasses are doing more heating than cooling of the combustion chamber. Ideas on getting rid of knock? Block EGR and throw a Weber on it?