Crank no start...but then does...

[Ninj43]

Is it cranking fast enough? The ECU won't fire the injectors if the engine isn't cranking fast enough.

Sounds like it but unless I catch it in the act and log the engine speed I'll not know for sure.
I suppose a sensor issue under reading engine speed may cause the Injectors not to fire?
Again we need some logs eh?

 

[DXX]

Is it cranking fast enough? The ECU won't fire the injectors if the engine isn't cranking fast enough.

Have you measured the battery voltage when cranking?
I had a battery that was cranking fine but was defective.

 

[Ninj43]

Will test and report in the am I'm assuming it'll start.
In some ways hope it doesn't so I can get some meaningful logs

 

[DXX]

Did you check the ground cable connection at the right hand upper engine mount? This is a common issue with Transporters, it will affect cranking current resistance and battery charging.
Look for corrosion up through the insulation past the terminal. Might look fine at a distance but could have many failed strands.

 

[Ninj43]

Not yet but on the list for the am

Thanks everyone some great suggestions here I'm very grateful will report back asap

 

[mmi]

I've had it a year. Very few miles around 1500.

It's had an EGR and AdBlue delete when it got a remap 6 months ago

How does coincide ECU reporting last DPF regeneration being 1120 miles (1809 km) ago? Remap?

I haven't checked the DPF stats for a couple of months but it was regenning as expected.

Hmmm... how do you know it has been regenning?



Also the voltage readings are somewhat low - though was captured only 9 seconds after startup. Thus a longer recording of blockmaps would be more than useful.

Also quite a range before running out of AdBlue

Please check exhaust tailpipe - is it sooty?

 

[Ninj43]

Very interesting........The remap and adblue/EGR delete were done 1131 miles ago, so its regenned 10 miles after and never again!

I was sure I had checked distance travelled since last regen and it was around 60 kms but that was about 500 miles ago so I've potentially been looking a failed regen report on the Autel.

The AdBlue range will be mental due to the removal.

Tailpipe is clean as a whistle

What did you spot with the voltages?

So, thank you @mmi even if this isn't the cause of the crank no start issue, it's saved me a blocked DPF at the very least! Ill stick a stock file back on asap and get it into a regen condition

 

[DXX]

I would think the actual soot level is going to be high after approx’ 1100 miles without a re-gen.
What the ECU reads maybe completely different if the DPF was ‘deleted’.

 

[Ninj43]

DPF is not deleted

 

[mmi]

Very interesting........The remap and adblue/EGR delete were done 1131 miles ago, so its regenned 10 miles after and never again!

it's saved me a blocked DPF

Well, hopefully - the pressure across the DPF is currently fairly high for a new DPF - suggesting the DPF regens indeed have been suspended. Would have expected to see well below 10 mbar at those conditions.

What did you spot with the voltages?

Oh sorry - the keyword was left out.

Also the voltage readings are somewhat - though was captured only 9 seconds after startup.

Voltage readings are somewhat weird. Just barely 12 Volts engine running - would expect to see more than 13.5 Volts fairly soon as engine has started. So hopefully the alternator just wasn't ramped up yet.

 

[Ninj43]

Yeh, definitely not been regenning - typically want 5-10mb at idle and under 50 at driving speeds......mines logging into the 250-300mb so it's done well not to complain but wasn't far away from a limp mode and glowplug light I think.

I see what you mean about the battery voltage - Ill run a proper test and another block map. Off to stick a stock file on it now and coax it into a regen or give it a clean as needed

Thanks again

 

[Ninj43]

So, took the van out for some logs - come back, left it 5 mins, crank no start is back. So I've got some VCDS logs and it doesnt look like weve got any fuel pressure.

By the time Id logged it, something has cooled down and its starting on the button again. This should give you some much better info @mmi - Please see below, the second of the 2 block maps is after the fault is cleared and the van is idling.

Just FYI, the van was sat on battery support at 14v throughout so that might sway what you see on the voltages

 

[Ninj43]

Just done a battery test, all looks good:
Cranking Time = 2665ms and 10.44v (normal)
Charging Test:
Loaded 14.79v
Unloaded 14.82v
Ripple 9mV
Overall health is 62% and its sat at 75% charge

 

[mmi]

I've got some VCDS logs and it doesnt look like weve got any fuel pressure.

Unfortunately true.

It seems that fuel pressure regulation does not do what's expected (red) - no change at all in the status. It should change to "Regulated operation via pressure control valve" immediately when cranking is started. Does this mean that fuel pressure regulator actually bleeds the pressure??? For comparison see

Spoiler: A successful engine startup

Post in thread 'Won’t start [Resolved]'

1 Aug 2021

Tick the following in VCDS Advanced Measuring Values,

IDE00021 Engine RPM​

IDE00347 Air mass: actual value:​

IDE00351 Main injection: start of activation​

IDE00352 Main injection: duration of activation​

IDE00407 Rail pressure regulation: status​

IDE00416 Starter control: terminal 50 feedback​

IDE00589 Fuel pressure​

IDE03767 Engine status​

IDE07757 Exhaust recirc.valve 1 bank 1: posit.feedback - Actual value​

IDE07771 Throttl.valve adapt. 1 bank 1: posit feedback - Actual value​

IDE07824 Tank-internal presupply pump 1 bank...​

• mmi

• 

Also noticed that in the logs of yesterday (22nd Oct) the fuel pressure regulator didn't behave as expected - although engine was seemingly running fine and fuel pressure was ok - a snippet below.

  IDE00407   Rail pressure regulation: status Regulated operation via quantity control valve
  IDE00589   Fuel pressure 30600 kPa rel
  IDE03767   Engine status Idle

EDIT: After checking quite a few log files it seems that also the condition above is correct. Obviously need to study further.

Also a bit mystery why the air mass meter (yellow) doesn't register much air (<0.4 g/s) - would expect to see 10 times more.



Would be helpful if you could record a successful engine startup and "hopefully" a failed startup - with the following parameters - trying to pinpoint the fuel pressure regulation chain.

IDE00021 Engine RPM​

IDE00347 Air mass: actual value:​

IDE00352 Main injection: duration of activation​

IDE00407 Rail pressure regulation: status​

IDE00589 Fuel pressure​

IDE01378 Fuel high pressure: control deviation​

IDE05632 Fuel pressure regulator valve actual value​

IDE05633 Valve for fuel metering: feedback value measured​

IDE07822 Fuel pressure regulator valve: activation​

IDE07824 Tank-internal presupply pump 1 bank 1: activation​

ENG125965 HPV current demand coming from the HPV control​

ENG125966 HPV current demand coming from the IMV control​

 

[Ninj43]

Definitely something a miss with fuel pressure regulation then. Would it be fair to say all the logs so far have shown an issue with the fuel pressure to varying degrees but a total failure is conicident with the no start??

So now I've got a stock file on the ECU, we're ruling out any monkey business with software. Ill run that last test tomorrow which will be very interesting to see if we have a fuel pressure issue still.

That's not to say the van hasn't always had an issue with fuel pressure of course, we've seen there it can run and drive fine with no logged DTCs but still have an issue only seen in the logs

Thanks again, really helpful advice

 

[mmi]

Would it be fair to say all the logs so far have shown an issue with the fuel pressure to varying degrees but a total failure is conicident with the no start??

Yes - that's exactly my thought and certainly needs to be investigated.

So now I've got a stock file on the ECU, we're ruling out any monkey business with software

Sounds good - at least the stock ECU behaviour is fairly well known and understood.

 

[Ninj43]

Yup

ok so good plan for tomorrow I'll get those logged.

Ill investigate any lines of enquiry with the fuel pressure reg valve - not sure how much of a job it is to change one on this engine but if it's giving spurious signals that could be the culprit.
We should see immediately if it's software or still present tomorrow

Coincidence is a funny thing - just popped up on FB:


I'm pretty sure Darkside always warn of removing an EGR on these where the DPF is still present.
Never really saw the issue, to my mind the EGR is fully closed during a regen so why would it matter that it's commanded shut all the time but this is familiar.

 

[DXX]

Yup

ok so good plan for tomorrow I'll get those logged.

Ill investigate any lines of enquiry with the fuel pressure reg valve - not sure how much of a job it is to change one on this engine but if it's giving spurious signals that could be the culprit.
We should see immediately if it's software or still present tomorrow

Coincidence is a funny thing - just popped up on FB:

View attachment 307060
I'm pretty sure Darkside always warn of removing an EGR on these where the DPF is still present.
Never really saw the issue, to my mind the EGR is fully closed during a regen so why would it matter that it's commanded shut all the time but this is familiar.

They have always said that but is it because they have a batch of replacement straight through exhausts to shift?
CFCA owner here running a blanked EGR with an emulator, no issues for tens of thousands of miles like many others.

 

[Ninj43]

Yup, makes no sense to me and I see nothing principally different with a potential link between EGR and DPF on this engine vs any other but Ill reserve a full statement for now

 

[Ninj43]

@mmi please see attached log. As you'll see a successful start (albeit as the glow plugs would have gone cold, slightly slower than normal)

I guess the question is, is the fuel regulation behaviour as youd expect?

To my untrained eye it looks like Regulated operation via quantity control valve is present as soon as it cranks?