[4dzrule]

When I work every day there are no issues, when I take a couple days off and it sits for a day or 2 its a little hard starting and then has missfire/rough runnning letting it warm up for a couple minutes and then for about a block from the house it clears right up. No smoke what so ever out of the exhaust and no codes.
I'm guessing there's an internal oil leak that bleeds off over time and is causing some air to get into the HPOP oil pump or rail? Any common areas that can cause this or is it something else?
The truck is an 02 with 233000kms (145000 miles) on it.

 

[tinman13kup]

The next time it gets to sit for a few days, take a minute and check the oil level in the HPOP reservoir. It should be within an inch of the top. There is a check ball that is supposed to keep the oil from draining back into the pan. perhaps yours isn't doing that.

 

[4dzrule]

I see, is this check valve servicable?