Fuel pump with carbs, Should it run all the time? Options

[brooks944]

Hi, I have a 1.8 ( now 1911) with 40 Webers and Web cam. It has run rich and my local shop has changed jets and it was running strong. I am now having starting problems and it seems to smell like it’s rich again. Last time I drove it it backfired a couple of times under load and it sounded like the backfire was from the carbs(?). My main question is on the fuel pump, which is a faucet type from the local auto parts store. Should the pump run continuously or shut off when a certain pressure is reached? Mine runs all the time when the key is on. I don’t believe there is a fuel pressure regulator on now.
Thanks for your help on my issues,
Rick

[Jack Standz]

Got the recommended regulator and gauge installed, thanks for all the help, fuel pressure is below 3. Went for a drive today and the car is backfiring under load. It sounds like the backfire is coming from the carb directly behind the driver, but I can’t be sure. Idles fine and can rev with no issues. What should I check into next? Thanks!

Backfires can be caused by several things. It means the mixture is igniting where/when you don't want it. This is not good. This can damage your motor.

Too lean or too rich mixture. Generally, a backfire through the carb is a lean mixture, a backfire through the exhaust is too rich.

Ignition timing is off.

Valve(s) is/are leaking.

Best wishes for a successful fix!