It looks like you're new here. If you want to get involved, click one of these buttons!
Sprinter cranks but wont start?
1. Did you put gas in the tank instead of diesel?
2. If you have access to a DRB (Daimler scan tool) check fuel pressure. You must have at least 2500 PSI to start.
3. If no or low fuel pressure the nasty little culpret may be a 25 cent o-ring. The fuel pressure regulator is located at the rear of the fuel rail on 2002 to 2004 trucks. Its held in with two little torx head screws and can be a mother to get out. It's not terrible you just have to work by feel mostly. Remove the electric plug and the two screws, then pull the regulator towards the firewall and it will come right out of the rail. Inspect the o-ring and back up washer on the end of the regulator. If you have a split or tear in this o-ring you just found your problem. Replace the o-ring and reinstall. Dont let your dealer try to sell you the whole regulator for $300 the o-ring only kit is part number is 05175439AA.
4. If this is not the problem you may have too much fuel bypassing inside worn injectors. You need to run a fuel quantity test. I will post how to do this in a separate post.