I need to change a fuel pump in my 1972 chevy longhorn 350

327 = 1969 Camero 2 bolt 210 hp.

passenger front.

This is for 1967 - 1972 Chevy 350 motor

Seem like your fuel pump can't keep up the pressure when engine is started. If you have a pressure regulator that isn't into the pump assembly i would change it if not then your going to need a new fuel pump assembly.

If the line is coming from the fuel pump and is not supposed to be pushing fuel into the flame arrester, the fuel pump has failed.

What I don't understand is why there is a small line going to the flame arrester in the first place. Its purpose is to dissipate heat to prevent exhaust gases from igniting any other gases that might accumulate.

My first thought would be a vacuum leak in one of the hoses. Rubber hoses get brittle with age and even a small crack in a hose may cause surging. Happened to me in a Lumina.

fuel tank
side covers
loosen air box mount bolts
throttle cables
manifold clamps
spray some lube to help

Check to see if there is any power getting to the fuel pump, if there is 12 volts going to the fuel pump then replace the pump, if there is no voltage present, the problem could be the fuel pump relay, a fuse, or a break in the wiring.

I have a 97 gmc sierra .This truck is the same as the chevy ok.Its a 350 5.7 liter 4x4 Z71.I took it to auto zone which was my first mistake.They put it the scanner and said bad O2 sensor.Ok so which one is it i said.They dont know.Well there four (4) O2 sensors in this truck i hope you know that.I had to replace all four of them before i had to take it to a real shop.It seems the fuel pump i replaced a week earlier with an auto zone fuel pump was bad.Ive changed my feul pump 4 times now and have 235000 miles on still running.You need to get your fuel pressure checked.It should be 65 psi to start it and 55 psi to run it.If the pressures are good it could be a different O2 sensor or maybe the mass air flow senor.My last option would be the fuel pressure regulator because it seems to be a waste of time and money.I would get that fuel pressue checked first.Good luck.

Mechanical fuel pump? or electric ?