bigdaddyice02

I guess the only thing I was thinking if it was cups then I would bleed off fuel and a bunch of white smoke, but I don’t use anymore fuel than normal and no white or for that matter any excessive smoke out of the stacks. Didn’t know if this is a common Mack problem with the MP8 motors or I’m just lucky Sent from my iPhone using Tapatalk

I run a 08 Mack chu613 pinnacle series truck with the mp8 motor. My issue that I’m having is on start up, it takes at least 5-10 minutes to finally start. It kicks over and tries to start but I believe it’s fuel related. My mechanic tried replacing the primer pump assembly, with the same result. I was told of a fuel over flow valve that I could try because it seems that the fuel is not holding where it should be when shut off for the night, believing the fuel is draining back causing the hard next day starts. My question is would that be the issue, or am I looking at more of injectors and injector cup issues?