Perkins getting hard to start

[Emmalina]

Hi All I have a Perkins 6354 that has been perfect for 12 years. Last week it got very hard to start due to gunge in the fuel line (pre filter) I cleaned the lines changed the filters and bled it all. I have got pretty good at this over the years LOL. Now when I start it it takes about 5-10 seconds to come to life as if its lost pressure. Once started its fine the same day but leave it a few days and it gets back to needing a lot of cranking. I am loosing pressure somewhere but is this just in the injection pump ? I have no leaks visible anywhere . Any ideas ?

[rbk]

I would check the valve clearances and give it a good tune up. Maybe a leak in the fuel line after your fix. Go over them throughly and tighten everything down all the way to the injectors just to make sure.

[Lepke]

If you had debris in your fuel line, there could be a piece under one of the lift pump valves. The valves are just one way check valves, one on each side of the pumping chamber. Debris can hold them slightly open allowing pressurized fuel to return to the tank.
Another fix is install a check valve between the lift pump and the tank.