parlry

I have a 79 rx7 with points ignition. It runs great almost all the time, but when I drive to school in the morning (about a 4-mile drive) the idle dissolves and it tries to die once the engine starts warming up. It doesn't seem to matter if I leave the choke pulled until it automatically clicks off, or if I push it in early. If I do push it in early the engine will idle fine at about 1000 rpms until the temperature gauge starts to move and then it will slowly deteriorate.

What I can't figure out is that it only does this in the morning. After leaving it sit for a little while (I've tried up to 8 hours) it runs perfectly for the rest of the day.

On a side-note (it's probably not connected, but ...?) my tach likes to jump around when I'm doing anything but accelerating normally. Also, my fuel pump sounds like it's about to blow up... kind of a steady rattling.

I've recently replaced the plugs, the points, and the coils (the idle problem was happening before all these). And I've removed the thermal reactor, air pump, etc., and replaced with a RB header (the problem started after this... but not immediately afterwards).

I'm totally lost on this one, so any help you guys can give me on the tach thing or the idle problem would be hugely appreciated!
-Ryan