OK ...Well the 3 wires on the TPS...brown is earth...one other is 8volt with the ignition on and plugged in...[ so you will have to bare back the wire to test ]....the other wire with meter volts change as throttle moved...[ again wire bare back to test ].... BUT Throttle switch will never stop the engine to start..that TPS is tied up with the Silver Ignition ECU...as well as the Black ECU..to retard the Timing if Pinking accurs on full throttle.....so plays no part in you say " not starting "....these cars with EVEN the Black ECU disconnected...will start from Cold...as 5th injector which is hard wired loom sprays neat Fuel in manifold...its what happens 3/4 seconds after ...then Black ECU takes over ....ie... starter cranking 50 circuit would have given Voltage [ varies ] re - water yellow sensor to pressure actuator to increase pressure to keep running untill warmed up...the actuator is "self resetting " once voltage goes on the warm up....again Yellow water sensor informs Both ECUs of a Hot engine....Make sure Pin 1 of the Black ECU is live on Ignition...colure Black / green....best i can help. oap pete