Our 1989 244 has occasional no start problems. (cranks, no start) Tonight I checked the computer readout per Bentley's and it showed a code of "3-1-2," which appears on their chart under fuel injection, as "anti-knock signal missing." Then I tried car, started perfectly. Restarted fine several times throughout the evening. I can't find knock-sensor in the Bentley book anywhere. I am checking all connections, replacing fuel pump relay, already replaced the in-line blade fuse with ipd's conversion....may replace the speed sensor on bell-housing if all else fails. So what's the deal with the knock-sensor code??? Tips would be appreciated, thanks, Dennis