Land Rover Repair: Start up problem, range rover hse, throttle position sensor

Question
I own a range rover hse 2006,I have a problem in starting fail, so the mechanical expert changed the fuel pump,it works but the second day I had the same problem so we change the crank sensor, I drove the car for around 1/2 hr and after parking it I tried starting it after 10 min but it didn't work.after 1hr I tried and it works,knowing that no faults appears in the computer scan at the mechanical expert.Any suggestions.thanks for your help

Answer
Hi Youssef,

no diagnostic faults, interesting.  

Here are a list of possible suspects from most common to rare:

Have you tested your battery and starter?  Perform load test on battery to be sure.  Solenoid can seize (rust, sand & oil sludge preventing starter cog engagement).

Next, park/neutral switch failure - won't start if BCU thinks vehicle is not in park. This is a common problem with all LR's.  

There's also a locking pin (c-clip) known to pop off and found on shifter.  Located in the 'T' part of the shift handle. Use a screwdriver to pop off the top of the "T" handle and look for a small c-clip. They are known to move and prevent starting (can actually prevent shifting out of park too).

TPS (throttle position sensor) failure can do this.

Ignition switch failure.

BCU (body control unit) could also be at fault,  rare but it can happen.

Best of luck,
JohnMc