3 fuel lines in 2 days!! help...

[etxxz]

I must be doing something wrong, but i just don't see what. i'm breaking an 8inch long piece of feed line to my s52..between the stock e30 hardline at the firewall to the feed side of the s52 OBDII FPR. (the regulator is on the return side, feed side is thru)

The line ruptures, more like it slits along the hose, not across it and right before the clamp on its underside 3/3 times. Am i overtightening the clamp? is the angle too much that the pressure is breaking it? Is the fuel line from advance auto parts a POS even though it says SAE rated fuel line on it. Too much pressure from my walbro 255 (doubt it) I didnt have this problem in my last s52. Your recommendation?!

...the hose i changed this morning lasted maybe 3 minutes and i lost like a gallon of gas to my garage floor

see image:


help appreciated. ty

-etxx

[Madhatter]

how tight is the bend and did you leave some slack in the hose to allow it to flex and bend when in use? you need to make sure you have some slack in it so the hose droops.

[george graves]

The dealer sells quality fuel line - I'd run that.

[Van Westervelt]

I have ALWAYS had an issue when I didnt run BMW fuel line. Anytime I have used the cheaper or off the shelf stuff, it has ruptured, or leaked.

Try that?

[jlevie]

Are you using hose rated for fuel injection service? Hose rated for fuel service, but not fuel injection service, won't be able to take the pressure. It is possible that your Walbro is over sized for this application, which could result in too much pressure into the FPR. Tee-ing in a pressure gage will quickly answer that question.

[Todd Black 88]

Are you using hose rated for fuel injection service? Hose rated for fuel service, but not fuel injection service, won't be able to take the pressure. It is possible that your Walbro is over sized for this application, which could result in too much pressure into the FPR. Tee-ing in a pressure gage will quickly answer that question.

This is more than likely your issue I think. There is two different grades(or more) of fuel hose. You need high pressure fuel injection hose. You will know you have bought the right stuff, as its about 10x the price of regular fuel hose. Its reinforced inside to handle the high pressures from the fuel pump.

[etxxz]

...hmm you guys are right.

i actually tried to remove all of the line slack to avoid stressing the bend..but the hose says SAE30R6KX (made in USA muahaha) and my walbro can do twice its burst pressure so that explains it. I'm going to replace these two lines and the fuel filter lines with some 250psi marine lines and call it a day.

lesson learned.
for the record there's sae30r7/sae30r9 which are for the mid/higher pressure fuel lines. ty all

[etxxz]

for the record. my walbro pump does 82psi at idle given that my 8year old gauge is tuned right so +-5psi; maybe 10 doesnt matter, the point is, regular fuel lines are not rated for this. I went to two dealers: Chevy (it was close) and bmw. The chevy had the same standard written as the AAP hose and the BMW hose said 50psi right on it. Neither of them had a higher rated hose...so i went to a Marine supply store, i got some nice thick 200psi 5/16" hose and called it a day. car runs like a champ now. good luck to all. pz

[kenika65]

Good info thanks!