I am running a 312 in my RHT, it starts and runs great. However after running at highway speed, when I slow down to turn into my driveway or stop it will quit running, but will start right up again. I have checked the fuel filter, it is new. checked out the carb and all seems to be ok. So my ? is will a weak fuel pump cause this, if so, how do I check this. To me it seems to be fuel delivery after slowing down, just not sure.
Temporarily run a fuel pressure gauge in-between the fuel pump and carburetor. Mount the gauge on the cowl area where you can easily read it. Should be 5-7 psi. Could also be some sort of restriction at the rear, gas tank, fuel line?
My Edsel wagon had a issue sort of like yours. The threaded outlet at the tank was about 75% closed off with rust and dirt. The car always labored going up hill or under hard acceleration and would sometimes stall completely. After cleaning the tank outlet the problem went away.
Are you running a dash pot? IIRC that sounds like the problem I ran into after removing the dash pot.
Alvin, that sounds more like a carb problem, not a fuel pump problem. If your 312 keeps running for some at an idle the pump is probably fine. I had one in a '57 wagon years ago that let the float bowl run dry if I let the engine idle for just a little too long. Got me stranded once on kind of a jeep trail off the main road while I was out of the car trying to dig myself out of being stuck in a little mud hole. Everything worked fine if I kept the revs up a little bit off & on.
Float?
This must be a recent development...no problem when I drove it a couple of weeks ago. I DIDN'T break it...swear!!! :005:
X2 on the anti stall dash pot.
In addition to checking for fuel pressure, I would also check for fuel volume . The carb float bowl(s) will hold sufficient gasoline to idle for a minute or so, so disconnect the fuel line from the carb inlet, and run a hose to a suitable container from the fuel line to the container, and start the engine up (warm), and let it idle for 30 seconds or a full minute. Then shut it off, and measure how much gas was pumped into the container. For a stock engine, and fuel pump, I like to see about a quart in 30 seconds, more is desirable on a performance application.