1957 Super 88, 371 motor rebuilt.No AC. Original Rochester 4 barrel carb rebuilt. Installed a rebuilt fuel pump (Fusicks 4646) with glass bowl as that was original to car. Last September 2018 the fuel pump failed. Replaced with the same from Fusicks and guess what, this September 2019 having issues again. The following is what I am experiencing. Fuel pump is front right hand side of the motor. Positioned behind the radiator and fan.

Sunny and 85 degrees in South Dakota. Car slightly surges at speeds of 55 - 65 mph. Drove 50 miles, no problems other than the slight surging. Had lunch with the in-laws and 2 hours later headed for home. 20 miles later got on the 4 lane and upped speed to 65. Started cutting out like it was missing, really losing power.
If I pumped on the gas pedal some times it would surge ahead and then go back to dieing out again. Then quit. Car would start back up if I left throttle at idle. Did this several times but when try to apply throttle to get going the car will die.
Let car sit for 1 hour with hood up to cool off engine compartment. Started up after that but would only produce power long enough to get one shot at getting her on the trailer(idles just fine). 30 minute trailer ride to home and started fine with plenty of power to get off the trailer and back into my shop. No spitting and sputtering.

My question - Is this a Vapor lock issue? If so how do I remedy the situation. I do NOT use any ethanol fuel in the car.
Could this be a vacuum issue, as this is a dual action vacuum and fuel pump combination?
Any thoughts or ideas greatly appreciated.
Lyn

 

It could be something as simple as water in the gasoline . Get a bottle of gas line de-icer that contains Isopropyl . (the expensive stuff )
Pour it in the gas tank , and it will mix the water with the gasoline and get rid of it .

Also look at the condition of all the rubber hoses in the fuel system , including those under the car .
If they look old , replace them .

 

there could also be a hole in the metal line running up the frame.you might try pressurizing the line for leaks.

 

To check fuel pump. Pull the Gas line from the carb, put the carb line in a 2 liter coke bottle, pull the coil wire off the coil, crank engine for 12-15 seconds. there should be about 12 oz of gas in the bottle. If not probably a valve has gone bad in the fluid section of the pump.

The top 1/2 of the dual action vacuum type pump doesn't have anything to do with your fuel issue or carb vacuum. It runs your wipers and windshield washer motor.

My guess is you could have a crack somewhere in your gas line or in the rubber line before the fuel pump. Could be the fuel pump but that is a lot of fuel pump failures in a short time.The good test would would to put a fuel pressure tester on the fuel line and see if it drops pressure in a short time. Find out where the problem is before you buy anymore parts, diagnosis gets harder as you change things.

 

Test fuel pump for VOLUME, for PRESSURE, and for VACUUM at the fuel inlet. (Not the vacuum developed for the wipers)

That's standard fuel-pump diagnosis.