Technical Ducato 2020 engine turns but does not start.

[fedupcamper]

@varesecrazy thanks for the tip in the other thread. I'll check that tomorrow.

 

[diego74]

check water temp, air temp, diesel/common rail pressure, etc.

Not sure what NOx refers to as that error code description can be generic, if it refers to the oxygen sensor it should not matter, if it is the EGR it can cause problems.

 

[fedupcamper]

I'll get back to you with some more data.

 

[fedupcamper]

More data:
I checked most of the connector I was able to find in the engine bay, refitted the ones I could reach, wiggled the rest. I checked the harnesses for damages/abrasion, could not find anything except for some grime, but they are designed for that (I presume).

Checking temperatures, pressures and everything else through ODB2: all looks normal, nothing strikes me as wrong.
Peculiar thing I noticed was that the pedal sensors seemed off. Two of them at about 20% and accelerator as about 80%.
While pressing down the accelerator, the values did not change. Only thing I noticed was that at the bottom, there's a semi-stop and then a click (as if you reach a button and then once activation force is overcome, it is pressed).
Don't know if that is normal as I've never tried that before.

Key in ignition shows these pressures for the fuel rail:

While cranking:
Commanded Fuel Rail Pressure: 34800kPa (about).
Fuel Rail Pressure: 56400kPa (about).

Car Scanner OBD2 stores the logs in a .brc format. I not sure how to open them outside of the actual app.

DTC:

 

[bugsymike]

Fuel Rail Pressure: 56400kPa (about).

If engine is actually showing 56400kpa when cranking engine that is around 560 Bar pressure at common rail so more than enough to start the engine, so to me the issue could be mechanical.
I only got a bit of the engine cranking video, so hard to tell if four good compressions, is it possible the enthusiastic pressure washing was allowed to get in air intake/aircleaner and as you were dring along it got suckled into the engine?
If so much more serious, but will only show with a diesl engine compression tester.

 

[fedupcamper]

If engine is actually showing 56400kpa when cranking engine that is around 560 Bar pressure at common rail so more than enough to start the engine, so to me the issue could be mechanical.
I only got a bit of the engine cranking video, so hard to tell if four good compressions, is it possible the enthusiastic pressure washing was allowed to get in air intake/aircleaner and as you were dring along it got suckled into the engine?
If so much more serious, but will only show with a diesl engine compression tester.

Is there something on the OBD2 that would show that water has entered where it shouldn't?

 

[bugsymike]

Is there something on the OBD2 that would show that water has entered where it shouldn't?

Not really, unless it can show inbalance between engine cylinders.
If safe to do it with engine off and key out, you could put a socket and bar on the crank pulley and turn engine over to try and feel four good even spaced compressions.
I assume at that age the vehicle is fairly low mileage?
So no need to suspect cambelt issues etc.

 

[fedupcamper]

Not really, unless it can show inbalance between engine cylinders.
If safe to do it with engine off and key out, you could put a socket and bar on the crank pulley and turn engine over to try and feel four good even spaced compressions.
I assume at that age the vehicle is fairly low mileage?
So no need to suspect cambelt issues etc.

Well its a 2020 Ducato, but it has run 162000km. But timing belt/cambelt was changed in January so should not be an issue.
I don't know how to do what you described, and not what to feel either. Can you hear it when cranking? Is it possible to hear it if I crank longer?

 

[bugsymike]

Well its a 2020 Ducato, but it has run 162000km. But timing belt/cambelt was changed in January so should not be an issue.
I don't know how to do what you described, and not what to feel either. Can you hear it when cranking? Is it possible to hear it if I crank longer?

So around 100,000 miles, not excessive in my book and providing cam belt job was done correctly that shouldn't be an issue. Especially if it was running perfectly before the "pressure wash".
Normally if cam belt fails the engine would spin/turn over much faster than normal, but with no distinct beats as no compression on any cylinders due to cam shaft not working correctly.
When engine is cranking over it should sound rhythmic with four distinct beats in effect, as it come to the compressions of each cylinder when on it's firing stroke.
If you were turning the engine over by hand (obviously with ignition key out) then much like in the old days of starting handles, as the engine is turned each piston will build up compression ready to fire that cylinder, so as you turn the handle it would feel a distinct resistance for separate equally spaced times as engine is turning, if good.
If a garage had suspicions about an engines condition they can remove either injectors or heater plugs, depending on what adaptors they use and then fit a pressure gauge to each cylinder in turn, spin the engine over on the ignition key and hopefully see four good pressure readings.
Any odd readings will indicate damage on that cylinder of the engine.
You could try a longer video and perhaps it will be a help.

 

[fedupcamper]

So around 100,000 miles, not excessive in my book and providing cam belt job was done correctly that shouldn't be an issue. Especially if it was running perfectly before the "pressure wash".
Normally if cam belt fails the engine would spin/turn over much faster than normal, but with no distinct beats as no compression on any cylinders due to cam shaft not working correctly.
When engine is cranking over it should sound rhythmic with four distinct beats in effect, as it come to the compressions of each cylinder when on it's firing stroke.
If you were turning the engine over by hand (obviously with ignition key out) then much like in the old days of starting handles, as the engine is turned each piston will build up compression ready to fire that cylinder, so as you turn the handle it would feel a distinct resistance for separate equally spaced times as engine is turning, if good.
If a garage had suspicions about an engines condition they can remove either injectors or heater plugs, depending on what adaptors they use and then fit a pressure gauge to each cylinder in turn, spin the engine over on the ignition key and hopefully see four good pressure readings.
Any odd readings will indicate damage on that cylinder of the engine.
You could try a longer video and perhaps it will be a help.

Engine was running perfectly before, I did have some problems with my car battery, occasionally the MIL would light up with the additional warning that the Start/Stop is not available, especially on longer drives (would happen while driving). Maybe I'd be able to borrow a pressure gauge to find out if all cylinders build up the same pressure.
I'll make a longer video tomorrow, but to my ears it seems to be rhythmical without skipping any beats.

OBD is not telling me much either, but then again, I don't know exactly what to look for.

The NOx-sensor failure warning is now gone, I'm assuming due to me clearing the faults. Probably will show up again if when I get this thing running again.

 

[diego74]

Hi,

Accelerator pedal potentiometer value is shown as 80% opened when it is not pushed down?, if so try to download the AlfaOBD or any other App and check if that value is consistent among the other apps, because that should be wrong.

You would also have to check compression, injectors fuel return, check the timing belt marks, and fuel quality maybe?.

Would you mind please check if you can export the live data while crancking and export it in CSV or TXT format?.

 

[diego74]

You can also try to disconnect the MAF sensor and the coolant temp sensor and try to start it, this is because that forces the ECU to work in emergency mode by assuming some sensor values, perhaps we can see a different behavior.

 

[fedupcamper]

Hi,

Accelerator pedal potentiometer value is shown as 80% opened when it is not pushed down?, if so try to download the AlfaOBD or any other App and check if that value is consistent among the other apps, because that should be wrong.

You would also have to check compression, injectors fuel return, check the timing belt marks, and fuel quality maybe?.

Would you mind please check if you can export the live data while crancking and export it in CSV or TXT format?.

yes, that what it showed on the app I used. I will try with another to see if it picks up the same values.