V70 D5 2004 Starting Issue

[Kelvin]

Hi, I've been a member a while but my cars been very reliable so not often visited. Browsing has helped find numerous hidden clips and screws though so thanks for that.

Unfortunately I have an issue with a friends car.
It is a 2004 V70 D5 Auto 163 Euro3 which, oddly I think, has the 6 speed AW box.

Its a bit long winded so the short version is it won't start after changing the pnp sensor and gearstick. The gearsticks been changed back now. It does crank.
Today I've got it to start a few times but only briefly.

Long version:
So far, the car had an issue which made it only use one gear. I offered to read the codes and see if I could suggest anything.
I wasn't sure and said I think the problem is either the gear selector, which had a damaged ribbon cable, the PNP switch or the wiring between the Gearbox and engine ecu. Can't remember the exact faults.

The owner removed the ecus, cleaned the terminals which were clean anyway and refitted. Swapped the PNP with his XC90 and swapped the gearstick for one I had in a scrap 2005 Euro 4 car. It fitted but the case was different.

I was then asked Ito clear the fault codes, which I did, then the car would crank but not start.

Since then the owner has soldered the ribbon cable and refitted the original gearstick

The car still failed to start.

This was a few weeks ago and I've looked into a few things.
A gallon has been added to the tank which was low.
The fuel pump relay has been replaced as I could see it wasn't working in VIDA, possibly damaged by over cranking?
I've got a good flow of diesel at the filter bleed.
However I could see no rail pressure on VIDA


Yesterday I noticed that the cranking speed was low on VIDA (200-250rpm), but sounds healthy.
I compared this with my car which cranked at about 700rpm.
I deduced that the cranking speed was too low to inject fuel.
So today I removed the two magnetic type gearbox sensors and gave them a clean. Intention was to swap for known good ones but both spare cars have different sensors.
Upon refitting them I could see on VIDA that the rail was pressurising and cranking peaked at around 270rpm.
I was able to start the car several times, but each time it cut out in a manner that I though was like being fuel starved.

Live data is interesting and I think I have 3 big clues I don't understand.
Firstly I can see the rail pressure, it is there and it gets high enough.
However the live data does not record anything on the graph, just constant 0hPa, which I did not notice until reviewing the data this eve.

Secondly I think the rail pressure increases too slowly and drops too fast.
On initial cranking there's a delay where we build ups the 1000s before we hit the 10000s
Then after the car has run and cut out the pressure drops off over a matter of minutes back to or close to 0.

Finally there is a CEM-ECM to pump relay channel on the live data. At no time during starting the car can a frequency detected.

I have checked the pressure sensors with a multimeter and believe they are in working order.

My 2 guesses, and they are very much guesses at this point are;

1. The HP pump is damaged by ongoing cranking, possibly at times dry? Therefore the check valve is letting fuel return from the rail.

2. There is a sensor issue and the fuelling is being cut by the engine ecu

I'm not sure if it could be an injector or even anything else.

Any advice or suggestions much appreciated.

Just of interest as well, last time I read codes on this car it would not start and it turned out the key transponder wasn't being accepted.
It then started on the spare key.
The issue now feels similar

[ITSv40]

You really need to post in the relevant forum for your car. This deals with the S/V40 up to 2004.

[Kelvin]

Not sure how I did that.

I've reposted in hopefully the right section.
Can't work out how to edit or delete this thread now.

if anyone can point me in the right direction thank you

[ITSv40]

Originally Posted by Kelvin

Not sure how I did that.

I've reposted in hopefully the right section.
Can't work out how to edit or delete this thread now.

if anyone can point me in the right direction thank you

These things happen😀

Only one of the admins can delete the thread. I think you have to ask them to do so.