I'm having trouble starting the 99 Disco I when she has been runnig for a while. Is the fuel temperature sensor an easy fix. I'm an amatuer in mechanics but appreciate a challenge. I got the PO125 Code (Closed Loop Fuel Ctrl Insufficient Coolant Temp). I'm I barking up the right tree. Thanks!!![/b]

 

The code you are getting is for the coolant temp. sensor not a fuel temp sensor which they don't have. Your coolant temp sensor is telling your ECU that the engine is still too cool to go into closed loop and thus you are running rich.
I am not sure where your temp sensor is located, but it does need to be replaced.
Good luck,
Mike

 

If it is the fuel temperature sensor it is on the fuel rail driver side (left) you can take off with out depressurise the
fuel rail as the sensor sets on the rail not in to it.

The coolant temp sensor sets just forward of the fuel temp sensor on the intake .