bought truck with 100k, on it. Replaced LP and installed pusher pump at 105k. Have had no problems for 60k. But recently it started taking longer and longer to get truck to fire up. Every thing else is fine, truck runs fine after it starts. Fuel pressure still ok at about 14 idle 7or8 going down the road. I have changed the fuel filter and bled injectors. no codes, just dosen't want to crank. How should I go about trouble shooting this problem. Thanks for any advice.