Hey guys this is my first post on here looking for some help. Looking to buy a 2004 cummins went to the dealer it wouldn't start.... He said it was the fuel pressure relief valve. He ordered on put it in and still didn't start he is taking it in to the dealer tomorrow I guess. What could it be? It turns over fine but won't fire. Is this something that should turn me away or no?

 

Could also be a really dirty fuel filter, water in fuel, low fuel rail pressure, low or no voltage to Injector Pressure Regulator or fuel rail pressure regulator, failing or failed fuel pump, FP fuse or relay, bad or dirty ground circuit connections.

 

Just yesterday I had an issue with my truck not starting, all of a sudden. it would crank but not start. Got a dtc of P0192. Code indicated low or no voltage to fuel rail pressure regulator, dirty fuel filter, bad or failed fuel pump. I started with the easiest task first. I pulled the electrical connector to the fuel rail pressure regulator, and cleaned the contacts. The contacts were covered with a white powdery residue, likely corrosion setting in. once cleaned, I also forced a bit of di-electric grease in the female connector, and reconnected it. By golly it worked! My truck fired right up. Your issue may just be that easy. Good Luck