Will not start when cold?

vauxhall 1600 petrol zafira. Car will not start when very cold. no air leaks found in manifold , changed both temperature sensors ,fitted new map sensor. all connections look good. diagnostic shows no problems but fault still there, any ideas.
Will start if hair dryer is blown over the ecu area. Once started car runs like a dream , no hesitations , misfires etc...
bob, September 2021


done
The fact that it responds to the hairdryer on the ECU aked me wonder if it's worth posting on some of the dedicated vauxhall forums or asking BBA-Reman

https://www.vauxhallownersnetwork.co.uk/threads/car-stalled-and-wouldnt-start-eml-light-on.244458/

http://www.bba-reman.com/forums/Topic72448.aspx

Dguu, September 2021
link Click here to see other fixes for Vauxhall Zafira.