Before i just give up can anyone help - poor starting D5

[Ga73]

Hi All

I have a 2011 V60 D5 and i'm at my wits end here. seriously thinking of just getting rid now.

The issue is poor starting especially when hot, it'll turn over but just not fire usually when hot.

Things i've tried, changed so far....

Changed fuel filter.

Replaced all injectors with low mileage used ones (also replaced the copper washers at the same time).

Cleaned out EGR which wasnt too bad anyway

Added a one way non-return value to the fuel line near fuel tank.

Replaced fuel pressure sensor with a used one.

Cleaned all earth points.

Replaced the starter motor with a reconditioned motor which didnt make any difference so took my one apart and cleaned it out and refitted.

Once the car is running it's great pulls like a train..when it doesnt start (when hot) if it's left for an hour or so it'll start up without issue.


I've also noticed as soon as i turn off the ignition the fuel pressure drops to 0...is this normal ?

If anyone can give me any ideas or pointers i'd love to hear...i'm all out of ideas now ... i really like this car but i need it to be reliable.

Ideas and suggestions really appreciated , otherwise it's time to cut my losses on this one.

thanks guys

[Lancee]

Did you ever look for any error codes ?

[Ga73]

I did, using vida and no codes to give me any pointers... 😕

[Baffler]

Originally Posted by Ga73

I've also noticed as soon as i turn off the ignition the fuel pressure drops to 0...is this normal ?

I'm not overly familiar with this engine but there is something not right with your observation above. I imagine you should be seeing around ~50psi at the rail with the engine switched off so perhaps you have pressure loss back to the tank...?

Does this car have a lift pump in or close to the fuel tank? If so perhaps it has become lazy/tired and is less effective when warmed up.

[Ga73]

Hi Liam

Thanks, yeah it doesn't seem right to me but I don't see how pressure instantly drops with engine off either.. I'm not sure whether the HP fuel pump should hold the pressure but I don't want to just keep changing parts.

I added the non return value inline just after the Intank fuel pump thinking this would help.

Anyone else have an idea on this?

Thanks Ga

[Baffler]

I understand your frustration, Ga, these things can test the best of us, but given the amount of work you have put in I think you should persevere. As you know massive pressures are being produced at the HP pump so concerned for your safety and don't wish for you to get injured whilst working in this area.

Most likely a non return at the HP pump to maintain pressure to the rail. Sorry, I've no idea where this fellow is nor if it can be replaced easily. Just thinking out loud here but if the lift pump has been lazy for awhile could this have led to the premature failure of the HP non return...hence the loss of pressure.

Is there the function in VIDA to monitor live fuel line pressure (tank to HP pump) under both cold and warm conditions? Just to see what the lift pump is doing under load.

In the meantime try pop another thread in the Diesel section and hopefully more knowledgeable D5 members can offer their insight. And perhaps give a local diesel pump (Bosch?) specialist a call to get a little more information on your particular pump...they may know of a simple fix.

[Ga73]

Hi Liam,

Thanks for the advice, really appreciated.

Gary

[Thassos]

Hi Gary,

I totally get your sentiment, and sounds like youve tried a lot of things so far which probably werent the source, keep going, and youll find it...

I have done plenty of tinkering on D5's although mines an older euro4 one so i dont know likely differences, simple tick list ones,

1- glowplugs and connectors to, easy to test, but you would probably get error codes for faulty ones, but worth a quick check.

The fuel side is complex, but.. things ive noticed, (just using a cheap ELM and torque pro) rail pressure is crazy high numbers, when running the fuel flow drops to 0 (foot off coasting), but not a lot of that much to do with starting!

Wonder what happens to fuel pressure pre and during cranking, ?

Maybe try a diesel specialist, to get an opinion? or get a dealer to diagnose it? but the cause is usually elsewhere to where your looking !,, its just a case of expanding "the could it be?" list , my last D5 troubles got me thinking the same (get rid of it) but in the end.. the cause .. was a burned out wire running behind the engine down to the DPF temp sensor.. the fix was so simple when i found it (couldn't believe it !).. so hang in there and persist !

Persistence pays.........in the end !

[Lancee]

Have you tried any real time data readings with Vida ?

[Ga73]

Hi lancee, I wouldn't know what to check really... There are no error codes.

Any idea what I should be looking for when it's not firing mostly on hot starts?