Help please,

I just bought a 90 westie and drove it 'cross country.  Somewhere in =
Kansas it started idling really low ( ~200rpm) especially when cold, and =
it runs rough (stumbles, or misses for lack of a better, more technical =
term) when accelerating, especially through the 2,000 - 3,000 rpm range.

The plugs, wires, cap, rotor, and fuel pump were replaced about 4,000 =
miles ago.

I live at 7,000 feet, and was at 3,500 or 4,000 when I first noticed the =
problem.

Someone here said it was the altitude and to either advance the timing a =
smidge or use higher octane gas???

Count me in for the $3, $5, $20 or whatever.

Lincoln