isx 450 hard start

[Kiko]

Hello again. I have bought a tool and did an injector test. They all passed, no air bubbles. This engine is a long cranking before firing after sitting overnight. When it starts to crank the fuel pressure will build right away up to 50 60 70 etc. when I do initially turn the key on and hear the fuel pump come on it sounds like I have some bubbles come out in the fuel tank. I am really scratching my head on this one. Anybody have any ideas.