fuel pump surging, why?? Options

[Tab914]

Another one for you guys...........

Here is the problem I am trying to fix. Whenever the needle in the temp guage gets to about 1/4 the fuel pump starts surging. This causes the idle to start to go up and down in rythm with the fuel pump. Also when under load the car stutters and shudders and kinda wants to choke.

Before the car gets up to that temp. it runs nice and smooth, strong on acceleration and no poping or backfiring on decel or anything. Just sounds great and runs fine. Idle is where it should be and fuel pump does not surge.

Here is what has been done. -Valve adjustement
-Dwell adjustement
-Timing adjustement
-Tested MPC as per proper ohms.
Parts I have changed- coil, plugs, ignition points, trigger points, condenser, rotor, cap and wires.

Questions:- what could make the pump surge like that?
-does it make a difference how the MPC wire goes into it's conector?
-How do I properly check the head temp sensor.
-Could the intake temp. sensor be the cause.

I am at a lost. Feel like I am going in circles. (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)

Has anyone had this kind of problem??
Desperate for advice. (IMG:http://www.914world.com/bbs2/html/emoticons/sad.gif)

Thanks, Dominic.

forgot to add. car is a 1974 2.0 with stock fuel injection.