Fuel line help needed 'urgent!'

[southernspeed]

I'm just fitting a TBI set up on my '78. As standard it has a 3/8" feed pipe from the tank and a 1/4" return pipe from the original mech pump to the tank. Is this 1/4" pipe adaquate for the TBI return line? Or will it choke it up at idle?
Thanks.

 

[surpip]

FWIR from lookin at my TBI lines under the truck, its the same, so im thinkin you would be fine,
but this is with out going and measuring the lines for you

 

[southernspeed]

Thanks. Been reading thru some old posts and it seems others have used this line but none have said about how it ran afterwards. Guess it was ok!

 

[loafer]

1/4" lines are too small...

I'm just fitting a TBI set up on my '78. As standard it has a 3/8" feed pipe from the tank and a 1/4" return pipe from the original mech pump to the tank. Is this 1/4" pipe adaquate for the TBI return line? Or will it choke it up at idle?
Thanks.

You should use at least 5/16" ID for the return line, especially if you are using a larger fuel pump than stock.

If you decide to use the 1/4" make sure you hook up a pressure gage at the outlet of the throttle body and check the pressure of the return line. It should be pretty close to o-psi, if it's more than 1 or 2 psi you definately should use larger fuel lines.

I went through this same thing...I was going to try and use the 1/4" line, but wound up running 3/8" return because the 1/4" was too restrictive.

 

[southernspeed]

I went through this same thing...I was going to try and use the 1/4" line, but wound up running 3/8" return because the 1/4" was too restrictive.

That's what I'm worried about. It's only a 15psi pump I believe so I may give it a go and see how it works out. Thanks.