Charlie Moua

iTrader: (3)

I recently upgraded my fuel line setup to run -6an lines under the car.
I didn't want to run into issues of shorting out my pump, ecu, or main relay/fuses.


Upon start up i forgot to secure tranny ground cable, and what happend was i notice some smog from the bay. I turned off car and notice where my SS fuel line had tiny bit of contact with the SS line (back of block) from the catchcan return. I secured the lines so they wouldn't touch. I also secured the tranny ground cable. On the 2nd try, the car started right up.

But that got me thinking....
if the SS feed line is touching the frame, wouldn't that act as a ground?
Maybe i'm not asking the right thing.






Q:
When using SS flex line under the car, does the line need to be insulated from touching the frame? For example:
- using plastic mounting brackets rather than metal.
- if using metal brackets, have rubber to insulate between SS hose & bracket

turbociv910

i cut a rubber hose and wrap it around any points that are hitting the frame.

wantboost

iTrader: (2)

The whole line isn't braided, just the outer sheath. Then there's a Teflon layer and finally the rubber portion that actually contains the fluid being pumped.

How was the line attached under the car?

The line would technically act as a ground because the fittings make the line conductive.

I'm always weary of running braided line under the car, it can easily be damaged/punctured by road debris and cause a potentially dangerous situation. I try to use hardline and secure it with adel clamps with rubber insulators or run it through the car (some sanctioning bodies require a fuel shutoff valve in the car within drivers reach to shutoff fuel in an emergency.) Plus running fuel lines in the car isn't that dangerous and using bulkhead fittings to put the valve inside the car creates numerous potential leak points. If you can run oil lines inside a car for a dry sump system then you can run fuel lines. Plus it protects the lines from damage. You can run braided inside the car which won't burst in an accident.

Charlie Moua

iTrader: (3)

metal U shap brackets & self tap screws under the car.




will do that tonight.

wantboost

iTrader: (2)

Do the brackets have rubber insulators? If not I seriously suggest swapping asap. You've basically made the outer braided layer a conductor from the engine bay all under the car to a fuel tank, plus the metal on metal of the hose and bracket could cause the outer layer to fray from vibration potentially cutting the hose.

So now you have a conductive piece of metal with fuel leaking all over it. That happens to be connected to a fuel tank

See what I'm getting at here?

Charlie Moua

iTrader: (3)

no it doesn't have any rubber insulator on the U brackets

I got the point.

however i'm trying to understand how or why it (fuel line) would ground out.
Wiring isn't my forte.

wantboost

iTrader: (2)

The aluminum fittings the line connects to at the motor are grounded, thus grounding the outer braided shell of the line. The metal brackets used to plumb the braided line do the same all the way back to the fuel tank. What does the line connect to as it leaves the tank?

Muckman

iTrader: (2)

Grounding isn't an issue but abrasion is. I use a nylon sleeve anywhere the braided hose contacts anything else.

Charlie Moua

iTrader: (3)

That's what I thought too but wiring/electronics is not my forte so my thought process lacks conviction. lol


thats the thing
if the entire engine (IM, block head) because of the groundinding wires (tranny, valve cover, t-stat housing)

AND

guys who run ss lines from fuel rail all the way to fuel tank cover.... wouldn't that mean it's already grounded EVEN if it(ss line) didn't touch any part of the frame ?