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.

 

[fedupcamper]

update #3:
Disconnected the sensors as suggested by @diego74, only thing I noticed in behavior was that the occasional rumble maybe disappeared, but otherwise nothing changed. I used the OBD2 expecting to get a faultcode for the disconnnected sensors, but it was clean, maybe I'm doing something wrong? I ran it twice under two different vehicle profiles "Fiat Ducato 2.0 HDI", and a more generic profile fit for all Fiat Ducato I guess?
Same result on both.

I managed to pull this very eloooongated screenshot, bare with me (it shows the pedal positions in percent, my feet were off all pedals at all times):

Cranked for a longer time this time, perfectly even and rhythmical, no oddities or anything that seems out of order.
I know the ECM (or maybe DCM) has soft locks for various things, Immobilizer, but also AdBlue. Can this be a strict SW issue where a parameter has been set in on of the ECU's?
Can I restart by pulling the main battery triggering a hard reset of the ECU's?
Maybe that's next on the list, but I can't go on much longer. Soon two weeks standing.

 

[ZaphodB]

Control module voltage 11.28v

 

[lycopersicum]

Re: not getting a fault code after disconnecting a sensor, on my van the fault only comes up after engine has been running for a few seconds.

 

[diego74]

Normally the sensor disconnection triggers the error as soon as you turn the key to the ON possition, many mechanics without scanners to clean errors have learned it the hard way, but it really depends on how the ECU was programmed by the guys at BOSCH facilities, so if you want to make sure you are disconnecting the correct sensors you can do this by reading the errors while the sensor is disconnected or by reading that sensor value with the scanner, coolant temp should have a different value when connected/disconnected, MAF is in change of air quantity and air temperature, you can check those as well.

The low voltage value also called my atention, but I guess it is wrong data from the scanner, you can double check this with a multimeter while crancking, it should not be very low as the ECU might be turned off due to low voltage, hence nobody will be injecting fuel to the engine.

As with regards to the pedal value, it internally has different potentiometers which usually have crossed values and are constantly compared by the ECU for any inconsistence, please press it down and check if the 80% value goes down to 20% while fully pressed and the one that is listed as 20% now does get increased up to 80%.

If nothing of this provides any useful information it would be time to check if fuel is reaching the cylinders or try to manually inject fuel via the air ducts, but I'm not yet familiar with these engines as I normally work with petrol ones where we use "starting fluid" to diagnose a fuel injection issue but it is not good for diesel engines.

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

 

[diego74]

I reproduced this video in full volume and I do hear some explosions occuring, try to feed the engine with diesel from another gas station, perhaps the "water in diesel" indocator/sensor is not working in your van, or try to purge it (x244 has a bolt in the filter case).

 

[diego74]

Do you think that the employee that washed your van could have triggered this issue?:

 

[fedupcamper]

Yeah noticed that too, did I mention I'm on my fourth battery so far? (and it's giving up on me too)