Here's a wierd one.

Ive got a fuel tank that was modified by Rockvalley Auto for an in-tank efi pump to run a 383 with port fuel injection. I'm getting a persistent gasoline smell off this car with the garage door closed. I pulled the tank and resealed the sending unit and put a new o-ring under the assembly for the pump. Everything seems tight, no wet spots. The tank will even hold pressure or a vacuum if I plug the vent line. the vent line goes directly to the charcoal canister. I started poking around with a high-tech hydrocarbon detector (new 1/4" vacuum hose stuffed up one nostril) and discovered that the stainless-steel braided hose I used to plum the feed and return lines stinks of raw fuel! This is up and down the length of the hoses with no fittings in sight. Bought this hose at the local speed shop--rubber hose with the stainless overbraid like you find from Russell or Aeroquip. Yes, I should have hardline instead, but this was done for expediency. The hose has been in for about two years now and this has become a problem only in the last several months.

The question is, should this type of hose be used with the high pressures seen in an EFI system? Any idea if this permeation is normal?

That type of hose is not great to use for fuel hose. The correct braid type hose has a teflon liner. The high pressure is only aggravating an already bad condition.

June 1, 2008; by federal law all motor fuel must have 10-30% alcohol by volume. Alcohol is incompatible with rubber hose. You have to use teflon lined stainless steel braided hose, unless you go to hard line. Alcohol will also become acidic due to absorbing water from the air; which will attack raw aluminum (such as extruded aluminum hard line). Holley anodizes all aluminum parts that come in contact with alcohol to stop corrosion.

Big Dave

Thanks to you both. That seems to be the consensus--alcohol in the fuel. In Phoenix, I think we get 10% alcohol in the summer and MTBE in the winter (might have that backward). The hose has been on there for two years or so and must have finally reached a point were fuel is starting to leech out at a rapid pace. I think I'm going to order a pre-bent hard line and then use some of the teflon hose where necessary.

In case anyone is interested: I called a couple of manufacturers of braided fuel line and they all seemed to agree that typical rubber-lined braided hose will have about a 2-year life in a gasahol application (Like E10). The alternative is teflon-lined hose which has the drawbacks of larger bend radii and either crimped fittings or special compression fittings or steel hard line. I've had some feedback that NAPA now sells a high-pressure fuel line that has a thin teflon (or similar) lining that is more impervious to the blended fuels.