V70: Engine Hello all v70 d5 misfire

[saltyjim]

Hello Everyone,

Long time reader and appreciater of this forum for my many previous Volvo models. Im good at reading and not bad with a spanner but not so great with computers so haven't really posted much on here before.

I have had many volvos in the past (xc90 d5, v40, s60r) and my most recent purchase is giving me a bit of trouble and I am getting a little lost as to the next step. So I have recently purchased the car to use as a winter runaround to replace a Mercedes Cls 🙃 I bought the car with a misfire from the seller so I was under no illusion it was going to need some effort, but as I have said that doesnt bother me and I presumed it would be an injector or something.

Now onto the next bit, so excited with my new purchase i bought myself a copied adaptor of volvo vida and the adapter off a chap on facebook and got to reading the codes etc. It had a few, one for a glow plug (fixed), one for the internal climate temp sensing fan being stuck ( fixed) and one for steering lock which again I have fixed with the great help of this forum so many thanks. I also have replaced the MAP sensor as that seemed to be stuck at 80c. Now onto the elephant in the room.

The car has a stutter / misfire which is very pronounced under 2000 rpm, after that it gets on boost and pulls fine without any issue at all. But under that it feels like it would struggle to pull itself out of its own way. The car doesn't smoke or use or, although it does have an oil level sensor code which is the only engine code it has . I am guessing that will need to be replaced at the next oil change.

I have checked as I say for fault codes, there are none, I have checked injector balance on vida ( see attached, hopefully) and I have bought a kit and done an injector leak off test ( again hopefully attached ) I would say the results are fairly inconclusive at this stage, although injector 4 does seem to be leaking back double what the others are its under the tolerance of volvo. For reference the leak back was done warm at idle for 60 seconds.

I am a little confused where to go next, I have got stuff for a compression check coming which was a bit of a nightmare as the glow plug hole is m8 and most of the kits out there are m10 minimum but that is on its way. Does anyone else have any thoughts ?

Many thanks in advance

[saltyjim]

Sorry, said was rubbish with computers here are the pictures

[ShadeTek]

Is the fuel pressure reading at idle within spec?

[saltyjim]

Hello @shadetek sorry I didn't see your reply I thought I would get notified when the thread had a reply to it so I apologise again. In answer, what is it supposed to be I can check on VIDA what it is showing.

Just for more info now I have tried / tested the following also since the initial post:

Compression checked, all 400psi apart from cylinder 4 which was about 395-397 hard to read but very close to the others

Sent injectors to diesel logic in Leeds and they have just phoned today to say there is not much wrong with them, so not worth a rebuild, a little low on idle speeds apparently but they are going to ultra sonically clean all 5 and recalibrate them slightly but they were all in spec.

Map has been replaced and Maf without results

Checked and cleaned egr without results

Did notice just before I took injectors out and sent them away I got a low boost code p0299 but I'm not sure how related that is and also a misfire code for cylinder 5 which is the first time I have had these . I smoke tested the intercooler etc and that seemed smoke tight and when I drove it previously as I said it certainly didn't feel low on boost, once over 2000 rpm it pulled very well. I did notice the arm on the right of the engine near the egr etc seemed a bit stiff im presuming thats for the turbo actuator so I have cleaned and freed that up in case that was what caused the low boost code. But needless to say it still misfires, it will be interesting to see how it comes back with the injectors but I dont hold much hope.

Thanks for taking the time to reply and read all my garb

[saltyjim]

Also does anyone know what the values coming out of the ecu to the injectors are supposed to be, as I know members have said to check the injector harness.

But other than visually I dont know if they are meant to have a certain voltage/ resistance down the wires to each injector?

[saltyjim]

Injectors back in, all fitted without issue.

Fitted new fuel filter also just in case.

Issue still present, feels down on power below 2000 rpm, feels less like a misfire now strangely more like a hesitation. But I'm guessing the misfire is being masked somehow 🤔

Any ideas from anyone would be amazing at this point as I'm running out of ideas

[37 RUBY]

Originally Posted by saltyjim

Also does anyone know what the values coming out of the ecu to the injectors are supposed to be, as I know members have said to check the injector harness.

But other than visually I dont know if they are meant to have a certain voltage/ resistance down the wires to each injector?

I think what this person experienced is what they are referring to https://www.volvoforums.org.uk/showthread.php?t=263547

[saltyjim]

Thank you for your reply I have had a read through that thread previously and had a visual check of the injector connections and they seem perfectly clean. I have also electrical contact cleaned and brushed them with no effect. Does anyone know of anyway or testing them for resistance or something?? 🤔

[37 RUBY]

Originally Posted by saltyjim

Thank you for your reply I have had a read through that thread previously and had a visual check of the injector connections and they seem perfectly clean. I have also electrical contact cleaned and brushed them with no effect. Does anyone know of anyway or testing them for resistance or something?? 🤔

Vida will have that data although I think with a std multimeter you will be hampered with testing. The voltage/amp draw cycle will be in milliseconds.

You could check for earth leakage at each connection in case there is a short or break in the circuit somewhere.

Did you clean the contact surfaces on the injector wiring connections with something abrasive or just spray them with cleaner ?

Have you gone through all earth connections linked to the injector circuit?

[saltyjim]

Ok I will check vida for the instructions etc thank you.

And I tried to clean connections with pin/ screwdriver to make sure each was as clean as I could get it.

I havent checked any earths yet, again I'm guessing vida would have details for that ?

Thank you