now that ive finished replacing all of my fuel lines on my engine w/ 5/16 fuel line, i realized i didnt use "high pressure" fuel line. Now im worried im going to need to replace all these! How much pressure does this fi system hold and do i need high pressure lines for this?

I believe you need to run the fuel pressure at about 29-31 psi and use high pressure fuel line.

Yup. High pressure line, and it's NOT 5/16" (8mm), but 7.5mm. That .5mm makes a TON of difference in the fit of the hose. All the usual suppliers carry it, as well as most VW shops. The smooth stuff is better, but the cloth covered stuff is OK, too. The Cap'n

hm. took the tank out and it all says fuel/emission line, 5/16(7.5mm) 50psi. so im guessing that will work. I was thinking i had some other stuff on there but its already ok.

The fuel/emission hose is the low pressure stuff. Good for carbs and vacuum applications. You really need the high pressure stuff.

well i asked the parts store for the heavy duty FI stuff, not just the gates hose on the reel for the carb cars, and they gave me the same stuff i already have. It says fuel/emission multi application or something, then 50psi. That psi should be more than enough right? I know the new stuff i bought was the right stuff, but its the same as the hose on the car that i got somewhere else. Same brand, same size, both 50psi!! Is the right stuff more psi than that? like 100psi or something?

Just my $.02, if you ever have a kink or something blocking the fuel system, the pressure will go above 60 PSI, it just doesn't sound right the multi application thing. Sounds just like on of those 32 in 1 tools that breaks within five minutes.

The fuel hose should have written on it fuel injection with the PSI rating. And I thought the proper size was 7mm from Dave Darling's diagram.

Mihai

HERE is a Gates tech. article on the differences. I went with the heavy stuff just in case. I also know that if for some odd reason the pressure regulator gets blocked the pressure can jump up to over 100 psi.