Engine does not start

Hello Motor Talk municipality, I have a Ducato type 244 2.8 jtd Bj 02 which has not started since today. For about a week I have always had to have a bit longer organs when starting, performance he has had as usual. What I have done so far:All contacts on the battery cleaned because 3 years ago the immobiliser has not worked properly, did not bring any improvement. Control times is checked everything as it should. High pressure cable open to see if diesel arrives when ignition comes in abundantly when starting the pressure change but not. The whole has started short time after I had fuelled ( tank was still 1/4 full). Errors are not shown error memory I can not read out. First question I have it can lie on the cam wave sensor? What can I still check or what could it still lie on? Is there anyone who knows about the vehicles in the room Lichtenfels? I am grateful for every help many greetings Jürgen