It's an old thread but I have recently purchased an 06 4.2 flat tray and I'm having the same trouble. Mainly it takes longer to start when it hot. The plunger is tight to pump and even when pumped a few times it makes no difference. I just serviced it and replace the fuel filter with a new ryco so it's good quality there. After it finally starts it blows a little bit of smoke but not heaps. Someone help cause I'm buggered if I know