Poor starting when warm

[Cloggy Saint]

when the car is cold it always starts first turn of the key and runs absolutely fine. If I stop and go back to start it again while the engine is still warm it takes 2 or 3 cranks before it starts and the idle is then very low and the ignition lights stay on until I give it some gas. It then runs with no problem. The strange thing is my old engine did exactly the same thing and I've since changed everything with the new engine, ecu, loom etc. What could this be?

[Brianmoooore]

Leaking injector comes to mind. Fuel in the inlet manifold makes the mixture too rich until it's sucked out by the engine, plus the fuel pressure in the rail will have dropped off and needs to be built up again.
Fuel pressure gauge connected up, and see what happens when the car is parked up is the way to check.

[Cloggy Saint]

Thanks for the tips. I'll do the temp'checks but the injectors sound like a good call. I fitted freshly refurbed injectors with the replacement engine and was a bit concerned at how easily they slipped into the the head and inlet