fuel return

Jcrane88 · 11-08-2006, 07:15 AM

im putting a v8 with FI and a inline pump and a return style regulator on my 84. should there already be a return line on this car? or do i have to get much more complicated. it had a 2bbl carb and a mechanical fuel pump.
thanks.
john

wrightz28 · 11-08-2006, 10:05 AM

Yes sirie bob.

jveik · 11-08-2006, 06:05 PM

i asked this question about my truck that im restoring and apparently, the block mounted fuel pump with a carb setup does not need a return line as it has a pressure valve deal in the fuel pump to not make too much pressure. apparently it was just an early GM attempt to prevent vapor lock in the fuel lines. for your FI setup i have no idea but i would assume it's needed if you have the fuel pump in the tank?

Jcrane88 · 11-08-2006, 07:54 PM

well i am installing a inline pump..so not in the tank....and a return style regulator so i have to have a return line...if i dont have one, how and where do i put it?

jveik · 11-09-2006, 09:46 AM

you just run it alongside the main fuel line, keeping it away from the exhaust and other stuff... my trucks original return line runs on the inside of the passenger framerail along with the main line and the vapor canister line. these are all metal tubes and at each end there is fuel line connecting them to wherever they need to be connected

Jcrane88 · 11-09-2006, 08:47 PM

how do i get my new return line ( if i have to run an entire new one) into the tank???

Jcrane88 · 11-11-2006, 11:49 PM

all i have figured out so far is that i probably dont have a return line........still the question remains... how do i get a return line into the tank???

Morley · 11-12-2006, 03:35 AM

Quote:

Originally Posted by Jcrane88

all i have figured out so far is that i probably dont have a return line........still the question remains... how do i get a return line into the tank???

Well, you could try going to the junkyard and getting a sending unit from an F body that had FI. The sender includes the top sealing plate for the tank with all of the lines needed (pressure line, return line, vent line, charcoal cannister vapor return line) plus it will have the brackets for mounting an in-tank pump (something to think about for making it all look factory).

jveik · 11-13-2006, 11:07 AM

yeah its that simple. just get the right number of outlets and youll be fine

Jcrane88 · 11-13-2006, 05:07 PM

well things cant be this easy
i opened up my trusty haynes manual ( not really) and flipped to the fuel and exhaust sytems for carbureted engines chapeter and it shows a picture of the fule line and labeled one as a return ...i crawled underneath my car and i have those fuel lines...i traced the one labeled return all the wayy to the engine bay. and its plugged into...ready?? NOTHING........can it really be this easy or is soemthing wrong??

wrightz28 · 11-13-2006, 06:08 PM

S/b coming off the charcoal canister in one of the fender wells then going back to the tank.

Jcrane88 · 11-13-2006, 07:03 PM

no..........i have all the correct vapor and ventilation lines connected

Jcrane88 · 11-13-2006, 07:27 PM

yeah i double checked. if you have a haynes manual look yourself page 4a-2 illustration 5.12
it lists four hoses with picture. Under my car matches that picture exactly
1: Fuel feed
2:Fuel vapor
3: return
4 Ventilator (this ends just after leaving tank at a valve)
Ive known for a long time that carburetors dont need a return...the only thing i can think of is that they put that its for the crossfire injection, which of course my car dont have. but i cant explain it any other way.

wrightz28 · 11-14-2006, 10:20 AM

Quote:

Originally Posted by Jcrane88

Ive known for a long time that carburetors dont need a return...

Correct, when you're using a mechanical pump.

jveik · 11-20-2006, 09:39 AM

well then just use an air compressor to blow all the dust and crap out of the unused return line and hook that heffer up!!! heh, my 73 chevy truck has the return line also that isnt hooked up. it was just a rinky dinky attempt to stop vapor lock

These Ads Open in New Window