We have a recently acquired 1991 318i. It has a fuel hose that is dangling near the fuel filter. I think it might go to the carbon canister, but I'm unsure. These seem to be unique from other E30s, it is different than my 92 E30 325i cabrio.
It also runs like crap when first started when cold, but is fine once it is warm, and I thought maybe this hose that isn't connected might have something to do with it.