Extended Cranking 2.0 Ecoblue (2020)

[Mute]

Hello!

When i try to start my van from cold (during 15c ambient so no glow plug light on the dash), it spins the engine over at normal speed but it struggles to fire for about 1-2 seconds before firing up. The cranking doesn't slow down. Then for the next 2-5 seconds it will run a little roughly. Not shaking the van or anything that bad, just a little rough. It will usually bong the alarm chime and flash up "Hill start assist not available" on the dashboard, then it'll right itself and run sweet as a nut. If i turn it off again within a minute or two of starting, the next start will also be sluggish but unlikely to have any error messages and just generally a little easier than the first cold start.

If i let it warm up before turning off, provided i come back to it and start it while it's still warm-ish (so within 30mins to 1hr), it will start right up perfectly, no extended cranking time, no warnings - just the perfect startup.

So in summary:

* Cold start = extended cranking, accompanied with "hill start not available" message
* 2nd Cold start = extended cranking, no error messages
* Warm start = perfect start
* Hot start = perfect start

The van in question: A UK spec (RHD) 2020 Mk8 Transit "Leader". 2.0 diesel engine "BKFB" in 130PS tune with 6 speed manual gearbox. The door jamb card says "2.0 I HPCR Panther Diesel" and "Stage 6.2" - i have no idea what either of those mean but they might be relevant.

Low Voltage Fault: the hill start warning during cranking sounds like a low voltage issue to me. It's the original battery (4 years old), maybe it's not as enthusiastic as it once was and the extended cranks just show its age? I'm inclined to ignore this symptom, i think if i can solve the extended cranking i'll defer replacing the battery for now.

Extended Cranking: made me think some kind of injector or fuel rail issue. I can hear the low pressure fuel pump as soon as i unlock the van and the van drives great, no lack of power even when cold. It's only when starting. That makes me think some kind of leak. The fact the van starts perfectly when warm makes me think there's a tiny leak somewhere that fuel pressure can escape only when cold, wherever the leak is, is expanding when warm?

I have forscan and a suitable cable so i hooked it up to see what i could find. Of the available PIDs in PCM mode i chose all the fuel pressure relevant ones. Turns out i chose a bunch that don't matter for this case so there's extra line charts in the below screenshot that don't add anything and can be ignored.

Screenshot 1: Start of engine cranking - this data is all from a "2nd cold start".

1 crank start.png

Summary: High pressure fuel rail measuring much lower than the desired value - suggests high pressure fuel rail hasn't maintained pressure?

* System voltage is 11.68v, a little lower than ideal but i haven't actually used a multimeter to check the accuracy of this reading yet
* Cranking pid just so i could see in the graph when the key was on
* Dechoke - ignore
* FLP_DSD (pink) - i believe this is low pressure fuel rail, desired value. The help text in forscan says the desired pid represents what the ECU would expect to see given the values of the other pids. At this stage in the key on process, i'm ignoring this pid.
* FLP (yellow) - fuel rail (low pressure) measured value
* FLP (blue) - same as above but reads slightly differently? very minor difference, looks to be a lower resolution version of yellow? I.e. it changes when yellow changes so it's not a smoothed / moving average because there's no lag, but it's definitely smoother so i think forscan is applying some smoothing and it looks smoother becasue there's less data than yellow. all just a guess
* FRP_A_CMD (pink) - high pressure fuel rail commanded value, what the ECU wants, the value changes in discrete steps i see
* FRP_A (orange) - high pressure fuel rail measured value
* FRP_A (red) - same as above but much smoother
* FRP_B - not used, 4 cyl engine
* FRP_DSD - desired value for high pressure fuel rail
* FRP_ABS - absolute measured value (i.e. including ambient)

Screenshot 2: 0.6s later, high pressure fuel rail has gone from 3bar to the expected 270bar. Low pressure fuel rail has been tracking a little above desired values but i think this is fine.

2 frp idle achieved.png

Screenshot 3: 1.5s from cranking start, cranking stops, the engine has caught (but roughly). High pressure rail is 30-60bar below desired depending on which trace you look at.

3 crank stop.png

Screenshot 4: taken at an arbitrary time after engine is idling smoothly. High pressure rail is tracking desired and commanded values as expected.

4 idling.png

So... it's time to go look at the engine. I did pop the bonnet (hood) and i didn't immediately spy the high pressure fuel rail but finding that and maybe it'll have some hard pipes to the injectors, i can check the nuts are all tight? Not sure, i'm sure i'll wing it and see... any pointers greatly appreciated!

[metalworker0]

Never mind the rest, your statement - "System voltage is 11.68v, a little lower than ideal " ..
says it all to me ....that's a lot lower than ideal.
The modern electronics need over 12 volt, more like 12,.25 to be without fault ,, ideally 12.75 to be bob on, all or anything will perform erratically if voltage is not correct ....so there will be a lot of misinformation given by code reader .

so get that sorted out ..new battery or check its charging ..something more than 13.25 volts when running , if its smart charging ...then i don't know how the smart system works.

all the best.mark

[Mute]

Thanks for that Mark and yeah agreed that voltage would be an alarm bell. I’m not sure how it derives that voltage but I didn’t trust it and just ignored it at the time because the starter motor sounds too strong to believe that figure. What I should have done instead of just assuming the figure was spurious was go get the DMM!

So I hooked up the DMM just now and it’s showing 12.3 but that’s with the key off but low pressure fuel pump running (couldn’t be bothered waiting for it to time out!).

IMG_2637.jpeg

I think the battery is on its 2nd half of life but I don’t think it needs replacing yet. Just to be sure I’ve got it on charge overnight to see if there’s any difference cranking in the morning.

I’ll need to see if I can figure out why the ecu’s derived voltage isn’t accurate though, I’ll bet that’ll play havoc with some subsystem or other if left unchecked! Last thing I need is immobilizer or whatever issues!!

[metalworker0]

running the battery down trying to start it can produce all sorts of faults ..

as well you could have bad earths ..but doubt a 2020 will have those.

highly recommended though

watch enough videos by these 2 guys and you wont be coming here

Diagnosedan
https://www.youtube.com/@Diagnosedan

TheCarCareNut
https://www.youtube.com/@TheCarCareNut

all the best.mark

[Dan transit man]

Did you ever get this sorted? Having the same issues every day on cold start, it struggles to fire and needs a few seconds cranking.
Recently went away and left it parked for a week. Got in it to come home and wouldn’t start. Called AA and both assumed battery but even with power pack took a good minute plus to fire. He said could be fuel pressure related.
Put a new battery on it when got home but still having same issues.
No faults on forscan.
Any recommendations?
Cheers

[DanMK7uk]

When was fuel filter last done ?

[Dan transit man]

According to the service it was 40k miles ago.
I’ll give it a go first.
Just come to start it and struggled after 3 days of sitting. Battery brand new.

[knobby1]

According to the service it was 40k miles ago.
I’ll give it a go first.
Just come to start it and struggled after 3 days of sitting. Battery brand new.

If the fuel filter full prior to trying to start..??

Lord Knobrot

[Dan transit man]

How would I know if fuel filter is full before starting?
I’m thinking it’s fuel related as if it were anything else, why would it be ok starting the rest of the day. It’s like the fuel draining out the system, the longer it sits.
I’ll get fuel filter changed, look for any obvious leaks and get forscan plugged in to see the live data on starting.
Injectors maybe?
2019 plate on 115k and we going away in it in 2 weeks time, which is fine if I start it everyday.
Cheers

[Dan transit man]

So I managed to hook up forscan quickly after finished work. Van took a few seconds to start and only took readings after it had fired.
Didn’t really know what to look at but went for low pressure side and it appears to be reading higher than it should be.
Maybe someone could let me know.
I have attached picture.
If anyone has suggestions for what live data I should take read then please fire away.
Cheers
Dan

IMG_8818.jpeg

Sorry don’t know why it rotated.

[metalworker0]

for what its worth this is what Google AI says

f your 2.0 EcoBlue engine is showing a "low side fuel pressure too high" reading, it most likely indicates a faulty fuel pressure regulator, which is the primary component responsible for controlling fuel pressure on the low side of the system; a malfunctioning regulator could be stuck open, allowing excessive fuel pressure to build up.
Potential causes for high low-side fuel pressure in a 2.0 EcoBlue engine:
Faulty fuel pressure regulator:
This is the most common culprit, as a stuck-open regulator can lead to excessive fuel pressure on the low side.
Restricted fuel return line:
If the return line is partially blocked, it can prevent proper fuel flow back to the tank, causing pressure to build up.
Fuel pressure sensor malfunction:
A faulty fuel pressure sensor could be sending incorrect readings to the engine control unit, leading to incorrect fuel pressure adjustments.
Clogged fuel filter:
While less likely to cause high pressure, a severely clogged fuel filter can restrict fuel flow and contribute to pressure issues.
What to do:
Check for diagnostic trouble codes (DTCs): Use a diagnostic scanner to identify any related fault codes that can point to the specific issue.
Inspect the fuel pressure regulator: Visually check for damage or leaks, and consider replacing it if suspect.
Check the fuel return line: Inspect the return line for any kinks, blockages, or damage that could restrict fuel flow.
Replace the fuel filter: If the fuel filter is significantly dirty, replace it.
Have a mechanic diagnose the problem: For accurate diagnosis and repair, consult a qualified technician who can properly test the fuel pressure system and identify the root cause.

and lot of differences between ecoblue to the 2.2 - so perhaps the wrong thread to post it on
my above answer was for ecoblue - which is what this threads entitled and about
all the best.mark

[knobby1]

How would I know if fuel filter is full before starting?

You simply remove it and have a look....if it's not full, you may have found your issue.....

Lord Knobrot

[Dan transit man]

So today I bought and fitted a new fuel filter. Plenty of fuel came out when draining ready to remove. Primed the pump with a few turns of the key and started on the second attempt.
Let’s just say I think either porky pies were told about the last change or they really do get so clogged after 40k

IMG_8832.jpeg

Time will tell if that does anything.
Forscan still showed high pressure on the low side.
I have noticed that the fuel pressure control valve is reading 0.00A. Should this not have some input or could this be the problem?
I’m not sure if it’s on the end of the fuel rail or this fella here with the orange clip on it?

IMG_8837.jpeg

Any more input feel free to share. I’d like one of these starting problem threads to finish with a solution.
Cheers
Dan

IMG_8834.jpeg

[knobby1]

40k is way too long to leave a fuel filter change.

Lord Knobrot

[Dan transit man]

So no change after fuel filter change. Still extended cranking after just over 24hrs sitting.
I’m going to have to check out this fuel pressure control valve next.
Does anyone know if it should be showing an amp reading when engine running?
Or could someone when they got 5mins, read theirs with forscan and let me know.
Mines a 69 plate 2.0 eco blue.
Cheers