Eliminate Return Fuel Line

B

Buick 430 Olds

Not-quite-so-new-guy
Nov 21, 2017
7
3
My 1983 Cutlass was a V6. It`s now a 430 Cu In Buick, 1967. I plugged the return fuel line at the tank and on the fuel pump. Now the fuel pump has quit working and I`m considering going to an electric pump. I`ve only driven the car 50 miles and it seems ok with the return line blocked but wonder if that led to the pump failure. Also not sure what kind of gas cap to use: vented, non vented, pressure, etc? Any input appreciated.
 
Bonnewagon

Bonnewagon

Geezer
Sep 18, 2009
6,303
113
Queens, NY
The return line is there to recirculate fuel back to the tank. That way you always have fresh cool fuel at the pump. This helps prevent vapor lock. With a big motor like that I would definitely want a return line in place. Get a new three port pump, use the return line, the charcoal canister, with a stock non-vented gas cap. The pumps are about $20 at Rock Auto.
 
B

Buick 430 Olds

Not-quite-so-new-guy
Nov 21, 2017
7
3
Thanks for the input on the return line. I`ll install one.
 
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TURNA

TURNA

Geezer
Jul 24, 2009
8,720
113
Socialist NY
Your pump failed simply because you didn't use the return

Look for a mechanical pump with 2 outputs instead of 3
 
Bonnewagon

Bonnewagon

Geezer
Sep 18, 2009
6,303
113
Queens, NY
When you cap off the return line fitting the extra fuel has to go somewhere. It usually goes to the carburetor and causes an annoying minor flooding condition only at idle. In normal driving you won't notice but the plugs will start to foul. The cheap-*ss solution is to place a "T" fitting in the fuel supply line and route the return line into that. Then the excess fuel goes right back to the pump. Using a two fitting fuel pump solves this too but then your gas tank is venting out- where? Right, nowhere. So in hot weather you get pressure in the gas tank that may flood the carb. You may even suffer a collapsed gas tank when the pump removes gas and no atmosphere can replace it. Then you may be tempted to uncap the return line and that will serve as the vent. If it is at the firewall you will have gas fumes exiting under your hood. Best to just use the three fitting pump as the factory intended.
 
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