What is the second line on a fuel pump for on a 1970 pontiac 350, and will it effect how the engine runs if capped off?


Asked by Sep 21, 2014 at 08:28 AM about the 1970 Pontiac Le Mans

Question type: Maintenance & Repair

3 Answers


That second line is a return line to the gas tank for cars equipped with air conditioning. It prevents vapor lock. It's not a vacuum line. In other words if your Pontiac has A/C there's 3 connections on the fuel pump. The one from the gas tank, the one to the carburetor, and the return line to the gas tank. If you do not have A/C you should only have 2 connections on the pump. One coming from the gas tank and one going to the carburetor. HTH. -Jim

2 of 2 people found this helpful.

I stand corrected. Thanks Jim, I believe you over the source I got that from

3 of 3 people found this helpful.

You're welcome, Fordnut. I had a '70 Catalina once upon a time. -Jim

2 of 2 people found this helpful.

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