My neighbor has a 2000 ho six speed and is having some problems starting in the mornings. Cold seems to make it worse, however, its been going on for about a year. The engine cranks like mad and slowly begins to fire until it takes off and runs on it's own. We put on a new lift pump, fuel warning light and new filter. No obvious leaks anywhere and the truck runs strong, averages 18 mpg, and has no trouble codes. What should we look at? The truck has 115,000 miles on it. Thanks