Warm start issues

[RupLaw 0]

1984 1.6 205 Gti, now being reluctant to start when warm.  When cold starts easily and immediately, after cranking for less than three seconds using no throttle, and likewise starts well when hot using full throttle.  But warm, requires a ten second crank before any sign of firing.  Any thoughts?

[Richie-Van-GTi 70 2 Cars]

Sticky SAD, dodgy ECU temp sensor would be my guesses.

Normally I would look at the set up but if it's otherwise starting and running fine then look at the above.