S1 Elise 111s Misfire

[moorbartat]

My Elise 111s has a difficult to find misfire that is cutting in the Misfire Detection unit and causing the coils to cut out. Tried different coils, oem leads, plugs. Even the diagnostic check doesn't bring up errors. The engine runs perfect until it warms and then cuts the coil.
Any ideas.
This seems to be a fairly common fault as I can find a number of posts with the same problem but without a solution.
All help appreciated.

[Krikkit]

Dodgy crank sensor? Often a culprit with hot-only misfiring.

[Hatchoo]

Other things to check are the coolant temp sensor to the ecu and the proximity of the leads to the crankshaft position sensor, if the leads are very close to the sensor you can apparently get interference which can result in mystifying misfires.

[moorbartat]

Thanks, I'll check the leads. I've tried two crank sensors, aftermarket and Rover, still no good