The mechanic at the local dealer has diagnosed that the fuel and ignition ecm's on my '89 740 are shorting out (if anyone's interested, I can take up the bandwidth to recount how he reached this reasonable, I think, conclusion). But the $2000+ to replace is way too much. So I'm thinking about picking these up used from a yard (understanding the risks with buying junked electronics). Can someone tell me where I find these two parts on the car? Or point me to the right FAQ? thanks