Firstfives.org

Well, it's getting close to completion. There's just so much I can do to get it ready for the referee. Wiring is complete, got a 179 ECU that makes it run so much better than the 150 unit. Changed the sending unit seal on the gas tank. I need to have the custom pipes brazed to the muffler, I cannot seem to clamp them tight enough to seal up.

Smog referee seems more hung up on failing me for a pin-hole leak in my vapor system than my fresh B34 with cats & lambda. Something the prehistoric 530i with thermals, air pump and prehistoric L Jetronic never had. I'm guessing the hoses back on the filler neck all should be replaced as well as the rubber intermediates on the way to the charcoal cannister.

I know silicone hose is bad for fuel systems, is it bad for the vapor system as well?

Have to see how this one progresses.

I'm not surprised they got testy about vapor emissions, about 10 years ago they really tightened that one up. Regardless, if silicone isn't fit for liquid gasoline, I don't think it would fare well for vapor gas either. I'd just go with plain old rubber, it lasts 15 years or so and it's cheap. I don't know how different the earlier cars are, but for later ones I just get 6 feet of each 6MM and 8MM and have a little left over. Or 1/4" and 5/16", that's close enough too and sometimes easier to find on the Sunday afternoon I usually seem to find myself doing it on.