Soaking won't remove most deposits in an injector, it just loosens them up a little. It really needs to be ultrasonically cleaned (preferably multiple times) and have cleaner run through it from both directions. I used WitchHunter Performance for the M30 injectors I sent off today because I'd used them before and had excellent results. For $21 per injector (plus $10 flat rate return shipping), it's a bargain IMO.
Quotes to live by:
guessing gets expensive
nothing is more expensive than a cheap BMW
buying a ratty example (of a BMW) is a parasitic relationship.(and you ain't the mosquito)
Ken Kanne, Silverhill, AL, E36 Forum Mod/Craigslist addict/Hoarder of all sorts of stuff
1995 318is "Bebe"; 1993 325is "Elvira"; 1985 635CSi "Katja"; 1984 633CSi "Sylvia"; 1987 325is "Odette"