It is caused by not having a return line to the fuel pump. I am surprised it is not flooding the carb????
Return fuel line need or not?
Thread Starter
Instructor
Joined: Oct 2008
Posts: 176
Likes: 1
Return fuel line need or not?
The other day I was covering my 77 after long drive and smelled gas near rear passenger side. Looked under car seen small puddle of fuel, dripping from frame. Using mirror seen rubber line from tank was leaking just before meeting hard line on frame.
Here is my question, should my return line be connected to system? Once apon a time previous owner unhooked and capped it. Could this cause pressure to hold in line cause it to fail, and cause rich conditions by over filing carb to point float and needle can't stop flow? Also when pressure checked pump had 13 psi.
Thanks for listen T
Here is my question, should my return line be connected to system? Once apon a time previous owner unhooked and capped it. Could this cause pressure to hold in line cause it to fail, and cause rich conditions by over filing carb to point float and needle can't stop flow? Also when pressure checked pump had 13 psi.
Thanks for listen T
Burning Brakes
Joined: Jun 2003
Posts: 1,079
Likes: 1
From: Niagara Falls ON
The piece that you need isn't that expensive. If you have a fuel leak in that part of the car that is the most common area for engine fires with C3's. Why take the risk, just replace it.
Le Mans Master
Joined: Sep 2004
Posts: 5,116
Likes: 5
From: Livonia MI
Seems like you have more than one problem there. As mentioned, 13 psi to the carb is to high, and tough on the float valve needle and seat. Should be more like 5-7 psi. Doubt a plugged return line from the pump has much to do with it, as only a small oriface fitting. Return line's a good idea though, as helps keep the fuel supply cooler, by looping some back to the tank. Really be more worried about the fuel pump 13 psi though, as that's the one sure to cause problems.
Racer
Joined: Mar 2011
Posts: 480
Likes: 42
From: Los Angeles CA
Seems like you have more than one problem there. As mentioned, 13 psi to the carb is to high, and tough on the float valve needle and seat. Should be more like 5-7 psi. Doubt a plugged return line from the pump has much to do with it, as only a small oriface fitting. Return line's a good idea though, as helps keep the fuel supply cooler, by looping some back to the tank. Really be more worried about the fuel pump 13 psi though, as that's the one sure to cause problems.
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Burning Brakes
Joined: May 2007
Posts: 1,042
Likes: 1
From: Greensboro NC
Don't know why a pressure regulator won't work. But I suppose it could cause issues with the stock type mechanical pump.
I have a electric pump and a pressure regulator on my 69 350/350 and it works well.
Previous owner had some local "mechanic" install the electric pump which was feeding the mechanical pump, and things went all to hell.
I have a electric pump and a pressure regulator on my 69 350/350 and it works well.
Previous owner had some local "mechanic" install the electric pump which was feeding the mechanical pump, and things went all to hell.
Le Mans Master
Joined: Sep 2004
Posts: 5,116
Likes: 5
From: Livonia MI
Based on "Frank's" observations, maybe redo the return line first, as good idea anyway. On rarely driven cars, I've been going rear mounted electric fuel pumps for many reasons. Mallory's 140 set up with engine mounted regulator seem's to be problem free. Still use an orfaced return line, and pressure gauge on the regulator, to keep an eye on things.
Thread Starter
Instructor
Joined: Oct 2008
Posts: 176
Likes: 1
Exellent, now does anyone have pic of how this return fuel line hooks into system? 77 gm service manual doesn't show it, neither does chiltons can't seem to find part that would "T“ into system in any of my wonderful catologs!?!
Thanks again T
Thanks again T
Thread Starter
Instructor
Joined: Oct 2008
Posts: 176
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Safety Car
Joined: May 2003
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From: Dearborn Heights Michigan