my 307 hdi 2.0 is always hard to start when its very cold i have replaced plugs .they dont seem to be getting any power . is this controlled by a temp sensor
of some sort and were is it ?and could i by pass it some how ?
glow plugs only work for 5-7 seconds when engine cold, these can be tested out of engine with a 12volt supply to them,but warning they do get scolding hot.i know theres a fuel heater box/relay under bonnet . ,i have the same prob with my hdi van. i found making sure battery was fully charged did help starting ,hope this helps.