I have a 2004 sprinter with 150k on it. Normally runs good but died on the road. Acted like it was out of fuel but isn't. Had it checked by local garage and they told me it needs a new high pressure fuel pump. Didn't want to spend that kinda cash on it without doing some checking myself. I don't have the scanner required but have some good mechanical instincts. I changed the fuel filter and tried getting fuel up to it but none came. Stuck the tank to make It has fuel. Seemed to have about half tank. How do you test the low pressure pump and could this be the problem. I checked the fuse panel and all seemed good and couldn't find a relay for it. Please help.