Weber carb question

[86goldmightymax]

I picked a 86 MM 2.0 auto with a Weber on it. The previous owner added a small electric fuel pump 2-4 psi and blocked the fuel return line. I am planning to to increase the size of the fuel pump (4-7 psi) then adjust it at regulator. Does it need the fuel return line hooked back up to run properly?

Thanks !

[geezer101]

Any reason why you need to have a higher PSI pump and then externally regulating it? Weber carbs only require 3-5 PSI of pressure to work - anything else will cause it to overfuel. If the Weber isn't running a return line and it's running properly, it won't need one now. If anything you need to focus more on fuel flow rates.

[pennyman1]

Webers need flow more than pressure - get a high flow rate low pressure pump and you will be golden.

[86goldmightymax]

Thanks guys,
It has a 2-4 psi pump and a regulator. It will only hold 3.5 psi and falls to 2 psi after few minutes. The previous owner said the truck wasn't save at hey speed because it would starve for fuel. He put a small filter inplace of the factory unit. I bet that is part of the problem.

[geezer101]

Thanks guys,
It has a 2-4 psi pump and a regulator. It will only hold 3.5 psi and falls to 2 psi after few minutes. The previous owner said the truck wasn't save at hey speed because it would starve for fuel. He put a small filter inplace of the factory unit. I bet that is part of the problem.

There is your issue. The fuel pump is being strangled by the undersize filter. Try a filter with bigger diameter inlet/outlets + hoses before upgrading the fuel pump.