I tested the current at the EHA and it was 19.9, engine off ignition on, about 7 mA directly after startup. 20 seconds later it was approx 4. When engine was warm it was fluctiating at about -3.5 mA (between -3.1 and -3.8 or something like that) (indicating that the lambda sensor was compensating for a rich mixture, right?) and I left it there since a little rich mixture would make cold starts easier according to another thread at this forum.

Also last night (a few degrees below freezing point) the engine was easy to start.

This morning however, it was in the garage (temperature about 5 Celcius (ca 40 F if I make a guess)) and this time it took a few second of cranking, then the idle rpm slowly rose to the warm up idle at approx 950 rpm....

I will exchange the fuel filter, I have bought a new one. But might the OVP relay or the fuel pump relay have anything to do with the strange behaviour at just over and at freezing point temperature.

By the way.... I did also connect a button (installed under the steering weel, hardly visable!) to a relay that I connected to the the cold start valve, will try to use it the next time the car doesn't start easily (to test if this is the problem).

Thanks! :-)