Pre-heat glowplug timing will still be on even when you have fired up, its normal, so is the heater vents calibrating for a short while as well as the throttle position sensor... All of them tick along on their own accord now and then.
I would be more concerned about the state of you battery and alternator. Go and get a check on both, Its a FREE check to do at many tyre and exhaust centre's and then you will know one way or another what is at fault.
Because your battery is in a constant state of having to charge/ discharge, your throttle, your ECU and relevant settings are constantly in a state of reference reset. Once or twice in a short period wont do any harm, but it will eventually end up loosing a lot of learned paremeters that are good too, Then if you have something as simple as a temperature sensor say being a bit tempremental but the ECU has learned a value that it can run at within parameters, that value will be lost and the car will eventually refuse to start for a silly reason that could be avoided.
Not worth the grief for the sake of a free check really, is it?