dear all , i have .....well its my wifes....an astra 1.7 dti.

it drives great from cold but when it is warmed up , after 25 mile or so it starts missfiring , very similar symptoms to a lead breaking down on a petrol engine...it also has a loss of power , a sort of lag , up to 2500 revs , then its ok after 2500 rpm.

when cruising at low speeds , 40-50 mph at very light throttle it missfires. if you put your foot down there are one or two misses and then its ok untill you setlle down again .

leave it stand for 20 mins and shes great again untill she gets warm.

ive changed the crank angle sensor and all the filters, oh and the cambelt, and there is no change.there is no engine management light on and no codes stored.

pleeeeeeeeeeeze can someone help , as ive not much hair left