Since winter arrived here Tuesday, my '90 740 wagon, non-T, stumbles and dies several times when started cold, then after 10 or 15 seconds establishes the right mixture and runs fine. The car occasionally had this condition in a milder form before the mercury plummeted, and I just finished cleaning the throttle body Sunday, when it started and ran well immediately in the garage. Can't find any loose vacuum hoses, so I suspect the IAC. The car has a Rex Regina system, with a VDO IAC, Volvo pt. # 1389 557 printed on the label. It appears to be sealed, so I don't know if squirting carb cleaner in there and swirling it around as described in the FAQ might make things worse. Hate to pop $200 for another, unless I get lucky and find the right Regina in one of the local boneyards. Does anyone know if this part is used on other cars, or if there's a reasonable substitute? And is it safe to try cleaning it? Thanks.