Have definite rattle, seems to be getting worse,pulls good ,no smoke,i have noticed it will turn over a few more times b4 firing up,where b4 it started instantly.Any suggestions would be much appreciated.

 

not sure if this is any relation to it, but if u pop ur hood and look directly on the right side of the valve cover, u will see 6 little blue pieces with i believe 8mm bolt head on it. i have heard that them become loose and need to be tightened back up. if they are loose they will rattle. i am not sure if this is the problem but i would check it out, maybe someone will chime in if that doesnt work

 

Could be loose fuel line clamp like mentioned or FCA could be going out. If your high side fuel pressures changes more then 500 psi at idle or if the fuel pressure is higher at idle then at 2000 rpm. Then you have a bad or sticking FCA. Since it cranks longer when starting you could also have injectors leaking or high pressure fuel tubes leaking.

Read TSB here:
https://www.dieseltruckresource.com/....html?t=271737

 

Thx for the replys.PULLED THE FUEL FILTER OUT,the rubber gasket was not in its correct spot,tightened up the blu isolators as well,no more problem,had visions of $$$ goin bye bye.