Hey folks, I'm at a bit of a crossroads here and was hoping for some insight for replacing a few of my old fuel and coolant hoses.

I've got about 5' of 3/8" hose I picked up to fix a "coolant leak" which turned out to be just a misrouted hose courtesy of the previous owner. Despite fitting comfortably where my ratty old fuel hoses came off, it says "not for fuel injection systems" along the sides and I don't want to use a hose that's going to lead me to grief. Before I go out and pick up a different length of hose though, I'd like to know if anyone knows (and can explain to me) why this hose might not be suitable for fuel transit purposes. To the eye, it appears identical to the original fuel hoses besides coming from a different manufacturer.

I'd like to replace all of the fuel hoses (not just the four short ones that I've pulled that connect the fuel lines running over the engine block to the fuel rails) and I doubt the length of hose I have will be sufficient to fulfill that, so I'll likely buy a length of fuel hose suitable to replace all of the hoses in the fuel system next time I'm at the shop, but I'm still curious what differentiates these types of hoses and whether or not it's unsafe or impractical to use a coolant hose to replace a fuel hose.

Thanks folks.

 

There are differences in the material composition and physical construction, what makes a good coolant hose doesn't necessarily contain high pressure fuel.
Remember, your coolant system is only pressurized to @13 psi where the fuel lines run about three times more pressure.
Real injector hose usually has an inner sleeve these days, so it's pretty easy to tell them apart.
It's also expensive as hell.

 

^ Bingo. Usually the liner is visible, but some aren't. Markings on the outside of the hose tell you what it is. And make sure you get 'fuel injection' fuel hose since it has a reinforced structure. Carb fuel hoses are only made to handle ~10 psi.

 

Most quality coolant hoses will withstand the pressure seen in your fuel system, but they will absorb the gasoline and burst, most likely causing a fire. Do NOT use coolant hoses in your fuel system!

You can get proper EFI hose from your local auto parts store (ask the clerk because it is usually in the back room on a bulk spool), or you can order it from online dealers like JEG's. You can buy fancy hose, but I just put SAE 30R9 hose in my convertible because it works really well even though it doesn't look fancy. Plan on spending about $6 per foot.