Occasional long crank problem

Hello everyone and Merry Christmas!
Trying to figure out the problem myself before repair shop rips me off)))

Experiencing long cranking no matter if engine hot or cold. Sometimes can start the engine right away and sometimes it will crank for like 6-8 secs before it fires up. If I use primer pump it fires up immediately. I remember it started doing that after I ran out of fuel in passenger tank (not sure if that’s related) because of clogged breather.

Replaced the fuel filter housing on drivers side and pressure valve on the front of the head. Didn’t find any visual leaks of diesel unless they are in a really hidden spot.

Went to the shop they connected computer and said they tested injectors. Said they’re working fine. BTW replaced injectors/cups(new style stainless steel)150k miles ago.

So the question is what may cause occasional long crank but leaking injectors? Can that be electrical problem? Fuel pump? Or can water separator housing somehow cause that?

Truck runs good, fuel mileage is still good like it was when truck been starting with half crank. No bubbles from return lines in fuel tanks when Truck is idling. No smoke. Even did oil sample no diesel/coolant/water found in oil. Cause I thought when injectors go bad there should be couple other signs along with hard start.

Just it will be really fun to throw in 4-5k for injectors and still have that issue.

It’s 2009 Volvo D13 manual 1052000 miles

Appreciate everybody and your thoughts about it!

 

Yes, sir. It’s Davco 382. But it’s hanging on passenger side

 

Thanks. No shops around me has that valve so I’ll have to wait till Monday when dealers are open. Just for experiment replaced water separator filter and after 200mi shut the engine and put a piece of tape on Davco to see the fuel level changes. After literally 5 mins level went up like 1/4 inch and truck struggled to start again for couple of seconds.

 

Is there any check valve on fuel pump that prevents fuel from draining back? When I hand prime it and handle gets tough to pump in the end I noticed a click coming from somewhere near firewall

 

No, I’ve been spying for bubbles for like 40mins))) haven’t seen a single one. Not loosing any coolant as well, today drained water separator, no coolant nothing just a spoon of algae