Start up fault

[Del94]

Hi again, I'm trying to record my van when in fault with my new VCDS. I think the attached might show the fault? The problem is the fault doesn't present every start up. Once when I was trying to record it the VCDS just displayed n/a in every column. I've ticked the boxes that delmassive highlighted on another thread.
Desperate to get to the bottom of this problem which the van first presented when it was 3 months old.
Massive battle with VWFS over the past couple of years. VAN is 2018 DSG I've attached the which is the first I've made. going to try and record more as I get more familiar with VCDS. Thanks in advance.

 

[mmi]

Hmmm... so what's the problem? No start, poor start? The logs don't indicate anything obvious....

Please do full VCDS Auto-Scan and post the result file.

VCDS > Auto-Scan > Start (VCDS detects all the controllers automatically for T6) > Save

 

[Del94]

Thanks for replying. Intermittent start up fault, most times starts perfect even stop start.
Sometimes just cranks until it times out without firing, sometimes starts on second attempt, sometimes takes several attempts.
A couple of Saturdays ago drove from Heathrow to Portland Dorset absolutely perfect. Went to leave 6 hours later van completely refused to start just kept cranking.
AA man arrived was not impressed about towing me to Heathrow he pulled a hose off (air intake?) van eventually started and drove perfectly all the way back.
Never leaves a fault code. Been in the main dealer a few times over the last 3 years, but I’ll do a scan again in the morning.
I would really love to get to the bottom of this van now has just under 47000 miles and I’ve owned it from new.

 

[Del94]

*removed air intake hose and sprayed easy start in while I cranked it

 

[mmi]

Thanks for the explanation. Well, no fault code = have to start from scratch. Still the Auto-Scan is always good start. Anyways, it looks like that I already have a scan of very similar engine than yours.

Let's grab full data package from engine and see if anything is stored in there.

Please record and post two "blockmaps" from the engine

1) ignition on (engine not running)​

2) engine idling​

How to:

VCDS > Applications > Controller Channel Map >


Tick/fill boxes as above and hit Go.
VCDS flashes screens for a moment (when finished hit "Done, Go Back") and there will be file blockmap-01-... in folder C:\Ross-Tech\VCDS\Logs\....

---

If you want to record the engine cranking - here is a procedure:

Won’t start [Resolved]

T6 204 diesel. Van was used on a long drive and then a trip to the shops. It was left 5 mins and then wouldn’t start. Turns over but doesn’t fire. no fault codes. There was a slight burning smell when I parked up and it looks as if the front egr pipe has a crack, rear one has already been...

www.t6forum.com

Let me know if more details are needed - the important bit there is ""Group UDS requests - by 7", which will significantly improve sampling rate thus allowing us to see events in great detail. Don't forget to start the logging.

 

[Del94]

Thank you. I’ll get to it in the morning

 

[Del94]

Hi, I hope these are ok, very new to this diagnostic business, fingers crossed

 

[Dellmassive]

are we thinking fuel rail pressure bleeding down?

possible fuel pressure leak back to the tank?

causing the van/ HPFP to have to re pressurise the fuel rail before starting and running.

so . . . . id be looking at the fuel rail pressure on VCDS?

before start, cranking, running. etc

 

[Del94]

Thanks for your reply. I’m a plumber by trade with very basic engine knowledge. Would this be like a non return valve failing should it be bleeding down?

 

[Dellmassive]

Thanks for your reply. I’m a plumber by trade with very basic engine knowledge. Would this be like a non return valve failing should it be bleeding down?

Yes, and no. ( well slightly with thermals etc)

The rail should hold a certain amount of pressure, ready for the next restart.

 

[mmi]

Well, if I'm interpreting the data correctly we should look into the camshaft timing -

In the data the suspicious value is the following:

IDE00182

Camshaft adaptation intake bank 1: phase position

2.9

degrees

Normally this is stable and not far away from 0.

Would be interesting to see if the value fluctuates during cranking, or soon after engine start-up.

Perhaps you could record an engine start-up and then 1-2 minutes on idle

Ignition ON
VCDS > Select > Engine > Adv. Meas. Values
Tick the following in VCDS Advanced Measuring Values,

IDE00021 Engine RPM​

IDE00182 Camshaft adaptation intake bank 1: phase position​

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​

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 1: activation​

ENG126043-ENG126092 P_L_Aps_camshaft_drift_angle-Camshaft target wheel drift angle​

Tick "Group UDS requests" - by 7.
Click Log - Start
Start the engine - (or even better if it just cranks).
Let engine idle for 1-2 minutes.
Stop logging etc.

The logfile will be in folder ...VCDS\Logs

 

[mmi]

The rail should hold a certain amount of pressure, ready for the next restart.

Mine doesn't hold the pressure - purges immediately.

TIME	IDE00021	IDE00589
STAMP	Engine speed	Fuel pressure
[sec]	[r/min]	[kPa]
108.65	827	30800
108.77	829	31000
108.90	830	30700
109.04	828	30900
109.18	827	30900
109.31	826	30800
109.45	829	30600
109.60	829	30700
109.73	828	30600
109.87	828	30600
109.99	827	30800
110.13	826	30600
110.25	830	30400
110.39	828	30700
110.52	827	30800
110.65	828	30700
110.79	828	30700
110.93	827	30800
111.07	833	30600
111.21	833	30500
111.35	707	400
111.48	598	300
111.62	539	500
111.76	402	500
111.90	54	500
112.04	0	500
112.18	0	500
112.32	0	300
112.44	0	500
112.57	0	500
112.72	0	500
112.83	0	300
112.96	0	500
113.10	0	300
113.23	0	0
113.35	0	300

 

[Dellmassive]

Mine doesn't hold the pressure - purges immediately.

TIME	IDE00021	IDE00589
STAMP	Engine speed	Fuel pressure
[sec]	[r/min]	[kPa]
108.65	827	30800
108.77	829	31000
108.90	830	30700
109.04	828	30900
109.18	827	30900
109.31	826	30800
109.45	829	30600
109.60	829	30700
109.73	828	30600
109.87	828	30600
109.99	827	30800
110.13	826	30600
110.25	830	30400
110.39	828	30700
110.52	827	30800
110.65	828	30700
110.79	828	30700
110.93	827	30800
111.07	833	30600
111.21	833	30500
111.35	707	400
111.48	598	300
111.62	539	500
111.76	402	500
111.90	54	500
112.04	0	500
112.18	0	500
112.32	0	300
112.44	0	500
112.57	0	500
112.72	0	500
112.83	0	300
112.96	0	500
113.10	0	300
113.23	0	0
113.35	0	300

Noted.

How can I duplicate that test on vcds to get the same data set and corroborate the results.

 

[mmi]

Noted.

How can I duplicate that test on vcds to get the same data set and corroborate the results.

Actually the setup for this is in the post #11 above - VCDS (HEX-V2) can even record all 12 parameters at that rate (0.14 seconds/full set). By recording 7 or less the sampling rate ramps up a bit (the Group UDS requests-thingy!)

The engine shutdown above was done by using Start/Stop-button - just to keep ECU alive measuring.

Of course the engine shutdown can be done simply by turning ignition off, however then also the ECU shuts down thus cutting off the data after a few seconds. The data cut-off can be eliminated by turning the ignition back on (not too fast though not to restart the engine).

 

[Del94]

What fantastic feedback, many thanks

 

[Del94]

Well, if I'm interpreting the data correctly we should look into the camshaft timing -

In the data the suspicious value is the following:

IDE00182

Camshaft adaptation intake bank 1: phase position

2.9

degrees

Normally this is stable and not far away from 0.

Would be interesting to see if the value fluctuates during cranking, or soon after engine start-up.

Perhaps you could record an engine start-up and then 1-2 minutes on idle

Ignition ON
VCDS > Select > Engine > Adv. Meas. Values
Tick the following in VCDS Advanced Measuring Values,

IDE00021 Engine RPM​

IDE00182 Camshaft adaptation intake bank 1: phase position​

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​

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 1: activation​

ENG126043-ENG126092 P_L_Aps_camshaft_drift_angle-Camshaft target wheel drift angle​

Tick "Group UDS requests" - by 7.
Click Log - Start
Start the engine - (or even better if it just cranks).
Let engine idle for 1-2 minutes.
Stop logging etc.

The logfile will be in folder ...VCDS\Logs

As a complete novice I will add this that I’ve noticed over the years my van has 3 start up (modes?) don’t know how best to describe it.
It either starts strongly and precise or starts with what I can best describe as a wobble or just keeps cranking until it times out and refuses to start

 

[Del94]

Hi the attached log was from this morning. Fortunately the van was faulting so this is just cranking before it would've timed out.

No fault at all yesterday but 4 times this morning before 11am.

I'm probably being completely dumb but I didn't think I could see ENG 126092 on my VCDS, wondering if I've not looked hard enough?

Best Derek

 

[mmi]

Thanks.

I believe the log reveals why the engine this time didn't start - very low fuel pressure in fuel rail (red below).

In the picture below only most "relevant" bits of the data. All of them in PDF-attcahment.



TIME STAMP -

IDE00021 Engine RPM - engine cranks very well​

​

IDE00182 Camshaft adaptation intake bank 1: phase position - normal, well it had changed 0.7 degrees since the blockmap log.​

​

IDE00347 Air mass: actual value: - normal (for the actual revs)​

​

IDE00351 Main injection: start of activation - normal​

​

IDE00352 Main injection: duration of activation - normal - injectors were driven open for 1.762 milliseconds (at each stroke) but probably the pressure was too low to actually open the the nozzles.​

​

IDE00407 Rail pressure regulation: status - normal​

​

IDE00416 Starter control: terminal 50 feedback - normal​

​

IDE00589 Fuel pressure - VERY LOW - should have been more than 25000 kPa within less than 0.5 seconds from start of cranking.​

​

IDE07757 Exhaust recirc.valve 1 bank 1: posit.feedback - Actual value - normal, EGR was closed (no recirculation)​

​

IDE07771 Throttl.valve adapt. 1 bank 1: posit feedback - Actual value - normal, airway open​

​

IDE07824 Tank-internal presupply pump 1 bank 1: activation - normal, fuel lift pump (in the tank) was activated (actually already before cranking)​

ENG126043-ENG126092 P_L_Aps_camshaft_drift_angle-Camshaft target wheel drift angle - normal

I didn't think I could see ENG 126092 on my VCDS, wondering if I've not looked hard enough?

It's actually in the log - the "address" for this is a long one in two parts "ENG126043-ENG126092" There indeed isn't ENG126092 as such.

---

Below a snippet of "normal" fuel pressure build-up during cranking (credit @aarona ) - please note the time stamps.

 

[Del94]

Many thanks, what would your advice be for my next action in solving this problem?

 

[Del94]

Really happy with the help so far - have never received any remotely useful input from the dealership.
But in there defence they never observed it faulting first hand only my videos.
VCDS has been fantastic so far - only my inexperience limiting it.