Here you can find the Bosch site with the Bosch parts for the Volvo 440 B18U (1.8i). According to the list you need the idle actuator listed as part# 0280 140 516.
edit:
I clicked on the image and it shows that 0280140516 is an idle control valve for the multipoint B20F engine! It is exactly the same part# which is on my idle control valve on my B20F. There seems to be a mistake made on the Bosch site, it is definatly not the part you need for your B18U!