OK, maybe you guys can help me out here. I have a 03 Isuzu NPR HD (W4500) with a GM 5.7 gas motor.

After the truck sits for any time longer than 20 mins, I have to crank it 6 or 7 times to start it. Once it starts it runs perfectly under all conditions. Fuel filter replaced, no change. I suspect it a fuel related problem. As if the fuel system is loosing its prime and it takes 6 cranks to re prime it.

Its in the shop now and they say its the fuel pump.. no question. Sounds reasonable, but the truck hauls ass pretty well for having a bad fuel pump. Quoted $500 parts and labor.

Any thoughts?