Car only starts with jump start despite full battery?

Car only starts with mobile jump start or external starting. The battery is fully charged to 12.8V. The car is idling but won't start. The car has only been driven twice in the last two years and has been standing still. The spark plugs were changed two years ago. My friend also installed his one-year-old…

Iveco Daily Transporter requires no (or hardly any) fuel, what could it be?

It's about an Iveco Daily Transporter that no longer pumps fuel properly. Every time you drive, it goes into the EDC. If you turn the ignition off and then on again, it goes on briefly. Furthermore, it only starts with starter fluid/brake cleaner. I've now removed the fuel filter and then let the line that…