I'm having hot starting issues with my 56 HSE. When it's cold it starts fine but trying to start it after a run is problematic. At best it lumps around then fires, sometimes prolonged and screeching sounds. I've read previous posts on this and I'm fairly sure it's the plastic cog/throttle body issue but just wanted a second opinion.

If it is the throttle body, why does temperature affect it?

Thanks for any help offered.

Don’t know the answer to that, but I guess if the throttle body flap is not opening, then less air is able to reach the chambers. Hotter air is less dense and carries less oxygen, so I suppose it is possible that there is insufficient oxygen to enable proper detonation.

Alternatively, perhaps the nylon cog is less strong/more slippy when it is hot, so the flap is less likely to open with a hot engine.

Hot engines can be a pain to understand...on my old V8 the rubber diaphragm in the SU carburettors would go soft in hot conditions and you had to take off the air filter and lever up the off-side carburettor piston at the same time as putting your hand through the window and turning the ignition! Got it all down to a fine art eventually, but gave me a worrying time, the first time it happened in 42 degree heat on a single-vehicle trip along the east shore of Lake Turkana! 2005 D3 2.7 Auto
Previously:
2010 MY FL2 TD4e GS - Now gone at 199,500 miles, about 135,000 of them mine.
‘93 Defender 110 200TDi CSW
‘87 Defender 90 4 cyl Petrol
‘83 110 CSW V8 - best ever!
Range Rover 2-door V8 (not sure of year - 4-speed box and vacuum diff switch)
Series III SWB Diesel

Thanks for the reply. Does anyone know if the throttle body issue logs a fault code? I don't want to get it done if it's not that.

My throttle body (diesel air intake control valve) got stuck at about mid travel. Starting was never a problem hot or cold but it did run on after switch off. It never produced any fault codes. Changing it had a very slight improvement in performance but nothing dramatic except instant engine stopping on switch off. Bit fiddly to change but not too difficult.

Thanks. Isn't hesitation during acceleration a symptom of throttle body trouble? I've got none of that or not that I've noticed

My throttle body was the noisiest thing in the world at shut down until it was changed but it didn't affect starting or performance in any noticeable way.

You might want to look at fuel pump pressure as a cause of hot start problems.

As you have "screeching sounds" I would change the throttle body although they tend to sound like that on switch off when they are failing.