Gasoline problems

[Whytock]

I have a 77 MGB and the other day i was driving up a hill and my car stalled. At first i thought since i was low on gas, and since i was going up a hill the car wasn't getting any gas. Because once i rolled back down the hill to a flat surface the car would run just fine. After getting the car home I replaced the fuel filter because it was dirty. But now when the car is at an idle and i'm watching the fuel filter. Gas is not pumped through at a constant speed. (not sure if it use to do this or not). It pumps for a while then stops and then pumps again and stops, is this right? and is there an internal fuel pump in the gas tank? what is the chance that it way not be working properly.
Thanks,

 

[dklawson]

There are two events happening. Inside the carb you have a float valve that opens and closes according to the level of fuel in the float bowl. When you turn on the ignition (before starting the engine) you'll hear the fuel pump chatter. The tone and frequency of the pump will change as it fills the carb float bowl and then basically "stops" in response to backpressure in the filled lines. When running, the same thing is going on, the float in the bowl is dropping, relieving the pressure in the fuel lines, allowing the pump to come to life and deliver fuel until the float rises and closes the valve again.

The easiest way to check the fuel pump is probably to disconnect the fuel line at the carb and put it in a glass jar. Have an assistant turn on the ignition while you start a stopwatch. When the jar is full have the assistant turn off the key and you stop the stopwatch. You'll then be able to calculate your fuel flow rate. If you post that here, people can tell you what is good and what is too low.

 

[Whytock]

Thank you very much
i'll try that

 

[Bruce74B]

It is also possble that your floats are sticking or need adjustment...sound like fuel starvation though, so you are on the right track.

Bruce