Ford Focus 2006 1.8 turbo diesel

Yesterday at work i got a ford focus 1.8 diesel (common rail) to do a sales service on. I went out to the car on the sales pitch and used the glow plugs as it was very cold. It started straight away but when i went to drive it into the workshop it died after setting off, at first i thought i had stalled the engine as quite abit of snow was in front of the wheels. I attempted to restart but it just spun over. It had fuel in but was only just above empty. A salesman put approx £7 of diesel in and tried to start again...no luck... now with a flat battery.
Pushed into the workshop and battery put on charge. Checked for any signs of fuel leaks and also plugged my obd scanner in with pulled up no dtcs. Spoke to another tech at ford down the road who informed me that they had no in tank electric pumps. Removed the return off the high pressure pump and forced fuel through using compressed air down the filler neck, reconnected the pipe once fuel was there and eventually it started and ran fine.
Changed the oil and filter this morning and it started straight up and ran fine for approx 3 mins. Went to drive off the ramp and it cut out and wouldnt restart...

I then connected my picoscope! used the preset sensor...fuel pressure...common rail
Read the waveform notes and backprobed the sensor signal wire. On this engine it had a distributor type 'rail' rather than the conventional rail i'm used to with kia and vauxhall.

First question... when i pressed the space bar and started the live reading on the scope, it automatically had channel B on (i had this on the other day with a canbus fault). How do i reset so it doesnt turn its self on?

I dont think i had enough time on the screen which could be throwing me off in totally the wrong direction. But basically once i rebled the sytem and got the engine running again the sensor matched the case notes almost exactly apart from at idle when the engine was switched off, the voltage just dropped straight off and not gradually (10 seconds approx)
Could this be a leaking injector or pump? If it was on the low pressure side ie fuel filter then surely it wouldnt start straight up?. I figured something was causing the problem as i accelerated off the pitch and my ramp...

My next plan was to scope the injectors but the salesman booked it into ford and i had to come away from it. This afternoon i was told that the fuel filter was replaced as it was blocked??? only time will tell if the fault is fixed and the car runs ok.

What do you think to what i've captured with the scope, am i barking up the wrong tree. It was very interesting to say the least...

Not looked at captures yet but would bet on P0251 being a stored code

On these TDCI's with that code the first port of call for me would be fuel filter/LP side, the second would be leak off

Robski wrote:Not looked at captures yet but would bet on P0251 being a stored code

On these TDCI's with that code the first port of call for me would be fuel filter/LP side, the second would be leak off

My scanner reported no codes and the ford dealer said there was nothing stored but did mention the filters were common, and it was blocked.
I did change a fuel filter years ago (probably was a focus) and I remember it been a total pig to get going. I thought I would break the scope out as I had a few mins spare and I did think it was leading me in the right or wrong direction!
When I've had cracked filter bowls in the past for example (mainly old School frontera's) it just would cause the fuel to bleed back and wouldnt start. But this focus started fine from been stood over night.

When I got it running in the workshop after 'bleeding' the system yesterday had it running for a good 30mins whilst I checked it over, if the filter was blocked then surely it would of cut out from fuel starvation?....

My scanner reported no codes

What scanners that then ?

I had an "after market" scanner on a 54 Focus TDDI with SRS light on....no codes read.......Put IDS on = 1 code.

I thought I would break the scope out as I had a few mins spare and I did think it was leading me in the right or wrong direction!

If you knew how to proof test the CR system it would have done,but you don't get HP without LP.

Robski wrote:

My scanner reported no codes

What scanners that then ?

I had an "after market" scanner on a 54 Focus TDDI with SRS light on....no codes read.......Put IDS on = 1 code.

I thought I would break the scope out as I had a few mins spare and I did think it was leading me in the right or wrong direction!

If you knew how to proof test the CR system it would have done,but you don't get HP without LP.

It's a aftermarket scanner but the ford dealers also reported no codes.

I understand the connection between LP and HP. I was more interested in what I had captured today with my scope. From what I could see and understand the residual pressure that the rail sensor was seeing was dropping almost instantly when the engine was turned off. Obviously I don't work on fords so I couldn't compare another but from what I've read and compared to a vauxhall would indicate a leak of some sort on the HP side,or a sticky injector etc....
As I mentioned before, if the LP side was leaking it would struggle to start but it started fine this morning after been stood all night.

I understand the connection between LP and HP.

the ford dealer said there was nothing stored but did mention the filters were common, and it was blocked.

Flow.

if the filter was blocked then surely it would of cut out from fuel starvation?....

A gauge would confirm this.

From what I could see and understand the residual pressure that the rail sensor was seeing was dropping almost instantly when the engine was turned off

Was this from a forced full pressure ?

I just did a waveform capture at idle, have you checked the uploads?

If I had a inline gauge I would of used it but it's not something we have. All I want to know is about the captures I have.

have you checked the uploads?

Yes

All I want to know is about the captures I have

What about them ?

Just to throw a couple of thoughts in: (as I have had fun with Ford Diesels too)

- The fuel filter also acts as a water catch. Over time it can collect quite an amount of water. In freezing conditions, it can freeze - and given water expands when frozen, it'll block the feeds!
Some filters have drains to allow you to purge the water, my pattern-part does not.

- Ford have some weird system (or simply a weak relay/lift pump) that simply stops working when the battery voltage drops below a given amount. Oddly, you'll find it can crank over for a good minute or two before giving out! The cold won't help either, with a weaker battery and more demanding starting requirement. This has caught me out a handful of times now, requiring a jump or bump.

- There is a common (or typically 'this happens') 'fault' with the lift pump - the power connection can become corroded, giving an intermittent fault. I've had a few reports of this, tends to be at the pump.

- Early OBDII Fords were pretty non-standard. I'm sure the 2006 should give some info (i'm talking pre-2000 - some ports were just for show!), but perhaps this looses it's codes when power is too low/cut? Is it talking the same protocol.

I have added the images into the first post to add clarity to the discussion.