idle and throttle problems
 

Ive got a complete nightmare, on the day of my MOT my 944 struggles to idle and wants to die when I open the throttle. The TPS is my best guess, but when I unplugged it, it didnt make much difference at all. How do I test the TPS and what is the next thing to check besides the basics. I got spark and fuel.

The voltage to the TPS is as follows: the two outside pins are 5 volts a piece and the middle pin is the earth,I think this is correct.

Please help!