starting issues, urgent!

hi again guys, i still on the case of my mk1 1983 golf gti not starting, i bee checking the CSV again today and the thermoswitch, they in them self work fine, but i don't think enough power on crank is getting up to the CSV, i tested it with voltmeter and it was only reading arond 5 volts. what i wanted to know is does the whole cold start wiring run through the fuel pump relay or fuse. if it is not the wring i can only think that is the system pressure. if there isn't enough pressure at the CSV would it not fire out fuel.
i belive that the cold start circuit is one wire running from the starter to the fuse box where it is feed to the CSV and THERMO TS and the earths are joined so that the THERMO TS open and closes to cmplete the circuit. i need to get this working properly before i can move on to any other starting problems. i havent done a fuel pressure test yet, but i will. been not starting for a while. another thing was when i took of the fuel cap there was a big pressure release, not sure if thats right.

Pressure release from the cap is normal - GTI's use a non-vented cap.

Disconnect the CSV and forget the TTS, they will not cause the car not to start - it will just take slightly longer.

5v at the csv seems pretty low, infact as that is the same circuit as starter I am suprised it is turning over at all, anyway as lhasa said disconnect it until you sort out starting, have you checked the ignition coil and module is getting good voltage as I would worry that something is amiss there as the coil wont fire very well with 5v driving it!