Rufblackbird

Hi everyone,
I have a '76 911S with CIS fuel injection. I've only had this car(my first Porsche) for about 3 months so I don't have a great deal of experience with Porsches. I need some help regarding the CIS fuel injection. When the engine is cold, it is impossible to start(it starts when warm, though). The motor cranks but it seems like fuel just isn't getting into the cylinders. I have checked my cold start valve and found that it wasn't connected to it's power supply. I connected it and tried to start the engine. Now it sounds like it's almost going to start, but once it does, it immediately dies. That said, I noticed that when the cold start valve wasn't receiving electricity, the fuel pump starts working as soon as the key is switched to the "on" position, but once the cold start valve is connected, the fuel pump doesn't start operating unless key is switched to the "start" position. Is that normal?
What I have done so far to try to start it is bleed the fuel system everytime before starting. Then engine cranks for a little while, then starts, sounding like it's struggling for fuel. If I don't press the accelerator a bit and give it a little gas, it will die. I have just changed the fuel pump, the fuel acummulator, the fuel filter, and the cold start valve(although I don't know whether or not it actually helps in starting the car) within the last 100 miles.
Once the car does get started, usually the idle is quite rough, usually it's at about 1100rpm; every few seconds it rises to about 2200rpm and back down to 1100rpm. The engine also backfires into both the intake(yes the pop-up valve was already installed) and the exhaust. What's going on? Should I have the cold start valve plugged in? I haven't replaced the injectors...would that be part of the solution?
One more thing that I have noticed. While I'm driving and reach a red light, when I press the clutch, shift into neutral(maybe I should start putting it in 1st like it says on one of the messages on this board) the rpms still stay at where they were when it was still in gear. After a few seconds, it goes back down to idle. Any help with this problem of mine will be greatly appreciated.

Jeff