NG Pinging?

[David.Ullrich at ferguson.com]

It's been an issue since I got the car in November 2001. I get pinging (even in cold weather) at times. I've changed the plugs, but the old ones looked OK. I've used several bottles of good fuel system cleaner. I've used Marvelous Mystery oil before each oil change to help clean her out (now the oil looks clean even past 3,000 miles, whereas before it looked dirty after 500). The car has the 2.3 NG in it, which is factory/locked in at set to 12*BTDC for the timing. I've tried various brands of gas, all 93 octane. Still pings. This engine, IIRC, is supposed to have a knock sensor and back off the timing if it detects pinging. I have no real clue where to start. Help!

Dave

Too Many Toys:
2002 VW Jetta GLS 1.8T Tiptronic
1993 RX-7 R1
1987.5 Audi Coupe GT "Special Build" 2.3 - Anthracite Black
1985 Chevy Impala Interceptor