My 63' Valiant has a hesitation problem when accelerating, just above the idle that makes it want to stall. If I flutter the accelerator, it'll get through it, but it's kind of annoying.

Also, last weekend I took it on a trip, and found that while going uphill for a while (above 65mph), it would begin sputtering and hesitating, and so I would just have to slow down a bit and get in the right lane. It did this consistently, almost every time I encountered a big hill or mountain.

Are these two problems related, and if so any idea as to what's causing it?

Work that has been done to it recently includes:
New plug wires, new plugs, set point gap, valve adjust, timing, new alternator and voltage regulator, had the head re-done due to burned valves, carburetor re-build, and finally I made sure that the choke is not sticking.

Thanks for your help,
Robert.

countchocula@forpresident.com

Both problems can be traced to a carb set on the lean side.

You gave a good overview of the problem but you failed to tell us which carb you are running, the Carter or the Holley? For now all I can say is to try to "fatten-up" the mixture a bit. (change the jetting to get it a little richer)

This is one of those trade-off deals, I would bet that you car gets pretty decent milage the way it is currently set but you get those lean carb. driveability problems, set it richer and it runs better but the MPG goes down, take your pick.
DD

The accelerator pump may be worn and not giving a full squirt, or your recent rebuild didn't install the pump properly. Maybe it just need a longer stroke. "Flutter" or pumping the throttle gives multiple small shots from the accelerator pump and helps cover up the problem. With the ignition off, remove the air cleaner, look down ther throttle and pump the accelerator. See if you get a good shot of fuel.
:
: Also, last weekend I took it on a trip, and
: found that while going uphill for a while
: (above 65mph), it would begin sputtering and
: hesitating, and so I would just have to slow
: down a bit and get in the right lane. It did
: this consistently, almost every time I
: encountered a big hill or mountain.

Might be a dirty fuel filter. The filter may flow enough for most situations, but not be able to keep up with the higher fuel demand going up hill. Durring a long uphill pull, the fuel level in the float bowl gradually decreases and the engine leans out. Your list of recent maintenance didn't include replacing the fuel filter, so try that.

dwordinger@earrthlink.net

One other area you might check on for the uphill problem is the sock or strainer inside the fuel tank. I have seen many of these on the old mopars that are almost plugged shut because of age and bad fuel over the years. I have also seen the fuel line itself restricted internally from varnished fuel. If this vehicle sat for an extended period of time or ever had varnished fuel in it then I would check the lines and inside the tank. If you have a new pump and inline filter, then disconnect the fuel line from the carb., ground the coil wire and crank the engine for 15 seconds while catching the fuel in a can. You should get at least 1/2 pint fuel in 15 seconds. If not then you have a restriction.