3 Port Fuel Pump to 2 Port Fuel Pump - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Mike Quillici · 07-13-2011, 01:41 AM

This is buried in the bottom of another thread, but I really need an answer to this question. I am replacing an OEM fuel pump with an Edelbrock 1721. My OEM fuel pump has three ports. My new Edelbrock has only 2 ports. What do I do with the third (return line) - How do I plug it??

MARKDTN · 07-13-2011, 03:52 PM

Just cap off the line. You can get caps at the auto parts store. I would protect it, you may want that line back some day.

jhngardner367 · 10-21-2014, 01:20 AM

The 3-port pumps have an inlet ,an outlet,and a return.the return is 1/4" and should go back to the tank.
I found out,the hard way,that plugging off the 1/4" port,on the fuel pump,will jack up the pressure so much,that it will flood the carb,and,eventually,destroy the pump.
With the return line run back to the tank,it runs normally,and fuel pressure is 5-9 psi .
When plugged off at the pump,pressure jumped to 13-19 psi !
I suggest using a 2-port pump,OR running the line back to the tank.

07-13-2011, 01:41 AM	#1
Mike Quillici Registered User Join Date: Oct 2009 Location: Sacramento, CA Posts: 161	3 Port Fuel Pump to 2 Port Fuel Pump This is buried in the bottom of another thread, but I really need an answer to this question. I am replacing an OEM fuel pump with an Edelbrock 1721. My OEM fuel pump has three ports. My new Edelbrock has only 2 ports. What do I do with the third (return line) - How do I plug it?? __________________ 1972 Chevy C-10 ~ 188,000 miles give or take

07-13-2011, 03:52 PM	#2
MARKDTN Registered User Join Date: Jan 2011 Location: Chattanooga, TN Posts: 2,144	Re: 3 Port Fuel Pump to 2 Port Fuel Pump Just cap off the line. You can get caps at the auto parts store. I would protect it, you may want that line back some day. __________________ '83 K20-TPI '73 C10 '79 C10-ex-diesel(SOLD) '07 Tahoe(Son driving) '14 Suburban-DD '71 C10-current project

10-21-2014, 01:20 AM	#3
jhngardner367 Registered User Join Date: Feb 2012 Location: Austin, Arkansas Posts: 248	Re: 3 Port Fuel Pump to 2 Port Fuel Pump The 3-port pumps have an inlet ,an outlet,and a return.the return is 1/4" and should go back to the tank. I found out,the hard way,that plugging off the 1/4" port,on the fuel pump,will jack up the pressure so much,that it will flood the carb,and,eventually,destroy the pump. With the return line run back to the tank,it runs normally,and fuel pressure is 5-9 psi . When plugged off at the pump,pressure jumped to 13-19 psi ! I suggest using a 2-port pump,OR running the line back to the tank. __________________ Always expect the unexpected,....but don't expect the unexpected to be the unexpected you expect ! I'm busier than a one-legged cat,in a sandbox! Veteran..and proud ! I can't fix what ain't broke....you want I should break it?



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