Panda multijet hot start issue

Having doubled our fleet of courtesy cars (from 1 to 2), we have come across an issue with FP2 (that's Fiat Panda 2, in case you were wondering. No prizes for guessing what the first car is called).

When attempting to start the car when it's hot, often there is no more than a click when the key is turned. Occasionally, the engine turns a few times, but doesn't catch.

- The battery is pretty new and in fine form
- The issue only happens on hot starting, cold is fine
- So far, the car has eventually started normally and run fine. It doesn't seem to be related to letting it cool down, as it can be after just a few turns of the key.

Any ideas? A little (probably paranoia-inducing) googling suggests it could be high-pressure fuel pump let-by or injector let-by, or (less dramatically) a dodgy earth. Since the starter doesn't turn the engine over and over, I don't think it's a fuelling issue and favour electrical, but we all know the extent of my expertise.

I would say that is an earth or the starter breaking down electrically when hot.
You could use a jump lead from the battery negative to the engine/gearbox to check the earth.

Thanks, Dazvr6, I might give that a go next time it plays up...

Diesel? I'd check your oil level if it is as you might be getting a fuel lock. I wouldn't have thought it'd be an earth fault as you'd get some random gremlins such as dim dash lights and DTCs.

The starter is plausible, I used to have a car that'd start reliably every second turn of the key.

The ancient trick of trying to start the car in the dark and seeing whether your headlights dim will tell you whether the starter motor is being energised or not.

Could be the starter relay or the starter itself. Next time it happens pop the cover off the fuse box and see if the click when you turn the key is the starter relay... if so, could be starter, if not, probably just the relay.

If it's the same as my Grande Punto the starter relay is a small red one, so for testing easily swapped with one of the other identical ones in the fuse box.

Thanks all. I am leaning towards it being a relay or dodgy connection because there are no other symptoms of poorly electrics. Nothing thrown up by diagnostics either.