3 Port Fuel Pump to 2 Port Fuel Pump

[Mike Quillici]

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]

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]

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.