Volvo Penta D4 260 Intermittent stalling and air block

[richtayrich]

Hi everyone, I'm perplexed at my new issue..
Volvo penta d4 260A-B - history - did after cooler and CAC clean etc in January and have done approx 40 hours since this.
Latest issue to arise is the engine started fine this one day, cruised for about 30 NM 3 hours , anchored, came to restart a few hours later, nothing..it cranked , no start. I checked the fuel filter and it was just air.., So bled it out and engine started fine, ran great back to marina , then under low revs felt slighty rough..back on the mooring, tried to restart it, same issue, fuel filter empty, re bled it and restarted, let it idle where is sat for 40 minutes chugging away.. stopped engine and went home. Next day, tried to restart..same issue..
So, I opened up the fuel tank to check for gunk, found it very clean inside, no gunk. blew through hose from tank to racor filter, clean, took off racor unit and stripped down, rebuilt with new filter, cleaned line to fuel filter, installed new fuel filter and rubber base gasket for sensor (cleaned sensor also), removed banjo fittings under CAC and on Fuel cooler and replaced all washers with new from VP...primed engine...ran for ages idling, stop started 5 times times to test, 6th attempt started, idled for 10 seconds and dieD..same issue..air in fuel filter.... what have I missed...

I even started it (after bleeding air) with fuel shut off and it created a vacuum in the fuel filter where the plunger stayed down and didnt raise up sucking in air... I just dont get it ..
ive seen the threads about the service bulletin for the newer component 21822234 for fuel leak (check valve ) but im not leaking fuel, im sucking in air somewhere and this came out of the blue...local mechs can’t fit me in Until October 30th..
Is it the fuel filter unit? diaphragm? leaking injector that has a moment?
Suggestions would be appreciated as lost confidence taking her out with this random issue, i don't want it stalling mid channel in the harbour ...too many sunseekers to bounce off...

 

[volvopaul]

Check the fuel banjo bolt on the cp pump , it’s likely if you had the intercooler off that would have been disconnected.

 

[julians]

Volvo penta d4 stalling

Have a read of the thread above,I had very similar symptoms to you with my d4 260 a-b and they were fixed in the above thread

I had no fuel leak, just air in the line

 

[richtayrich]

Check the fuel banjo bolt on the cp pump , it’s likely if you had the intercooler off that would have been disconnected.

I removed this and cleaned it up, put on new washers and new bolt , tightened to kind of wrist tightness as told not to over tighten … still does it , should I try one more turn ? Or sand down surfaces ?

 

[richtayrich]

Hi Everyone, so an update - After I replaced all the washers and new Bolts ran engine and it stalled... left it for a few days (as fed up), went back to it yesterday and before priming the fuel filter, I closed the fuel tap and then proceeded to pump the primer, causing a vaccuum, where the primer head stayed down.. i thought, well if theres an air leak it should start to rise up eventually... it moved a little and I ended up fiddling with the black primer button and twisting freely around... since then..not one stall, Ive had the engine running and off for 5 hours, left over night, stop started at least 20 times, left for an hour, restarted again and again.....no stall.. do these fuel primers/buttons tend to have an issue ? would spinning the black button really do anything differently? or have i delayed the inevitable...? its one of those...is it cured or simply hiding waiting to re emerge...

 

[Meagain]

Hi Everyone, so an update - After I replaced all the washers and new Bolts ran engine and it stalled... left it for a few days (as fed up), went back to it yesterday and before priming the fuel filter, I closed the fuel tap and then proceeded to pump the primer, causing a vaccuum, where the primer head stayed down.. i thought, well if theres an air leak it should start to rise up eventually... it moved a little and I ended up fiddling with the black primer button and twisting freely around... since then..not one stall, Ive had the engine running and off for 5 hours, left over night, stop started at least 20 times, left for an hour, restarted again and again.....no stall.. do these fuel primers/buttons tend to have an issue ? would spinning the black button really do anything differently? or have i delayed the inevitable...? its one of those...is it cured or simply hiding waiting to re emerge...View attachment 163878

Couldn’t be 100% but, I’ve just had a similar issue, replaced the unit and all my problems sorted. There again finally got to the stage where the primer pump failed to go ”hard” so a lot clearer in terms of where to look!

 

[richtayrich]

Couldn’t be 100% but, I’ve just had a similar issue, replaced the unit and all my problems sorted. There again finally got to the stage where the primer pump failed to go ”hard” so a lot clearer in terms of where to look!

Couldn’t be 100% but, I’ve just had a similar issue, replaced the unit and all my problems sorted. There again finally got to the stage where the primer pump failed to go ”hard” so a lot clearer in terms of where to look!

Thanks, Yes, Ive ordered a replacement to fit next few days..even if its not this, at least narrowing it down

 

[richtayrich]

Update for everyone and Anyone - Ordered and installed a new Fuel Pump primer housing (came with new filter and sensors)
Ran engine for around a total of 6 hours working up to operating temps, in gear etc..Given boat a full blast since,, WOT 28 knots , pootling around at 1000rom . Mooring up, restarting etc.. No issues.. So hopefully this was the problem..as like most things now, the slightest engine noise and Im carfeully listenning hoping nothing is goping to stop.,.....