Return fuel line need or not?
#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
#2
Burning Brakes
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.
#5
Le Mans Master
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.
#6
Racer
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.
#8
Thanks everyone. It is a aftermarket pump, I also thought 13 psi seen high for a carb.
Next question, if unable to find pump with less pressure would a regulator do the trick?
Next question, if unable to find pump with less pressure would a regulator do the trick?
#9
Burning Brakes
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.
#10
Le Mans Master
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.
#13
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
#14
Race Director
No pics handy,
From the pump, rubber hose to 1/4" metal line
To pass sideof gas tank
To rubber line to top of gas tank 1/4" nipple.
There is no "T"
Pump has separate return nipple.
From the pump, rubber hose to 1/4" metal line
To pass sideof gas tank
To rubber line to top of gas tank 1/4" nipple.
There is no "T"
Pump has separate return nipple.
#17
#19
Safety Car